Biology: Chapter 3: Enzymes: Inhibitors

Biology: Chapter 3: Enzymes: Inhibitors

• Enzyme inhibitors reduce the rate of reaction by interfering with the enzyme in some way.
• Can be temporary or permanent.

Competitive inhibitors

• Another molecule, with a similar structure to the type of substrate the enzyme catalyses, binds with the enzyme, inhibiting it's function for other substrates. 
• The competitive inhibitor therefore creates competition for the substrate, lowering the rate of reaction as the substrates have less enzymes to bind to. 
• Rate of reaction depends on the concentration of substrate and inhibitor. More inhibitors - lower rate of reaction.
• Usually temporary as the inhibitor will leave the enzyme after a certain time.
• Example: Ethylene glycol is used as antifreeze, and can sometimes be drunk accidentally. In the body it is quickly converted to oxalic acid, which causes permanent kidney damage. However, when the person is given ethanol, ethanol acts as a competitive inhibitor, slowing down the reaction of ethylene glycol long enough for it to be excreted. 

Non-competitive inhibitors

• Molecule that binds to another part of the enzyme, called the Allosteric site, affecting the bonding in the 3D shape of the enzyme molecule and altering the shape and shape of the active site so substrates cannot bind to the enzyme. 
• Enzyme will be blocked no matter how much substrate is present, which is why it is called a non-competitive inhibitor.
• Usually permanent, denaturing the enzyme they exhibit, which can be lethal.
  
• However, temporary non-competitive inhibitors are essential for metabolic reactions. This is because reactions need to tightly controlled as so they don't 'run wild'. 
• Temporary non-competitive inhibitors allow products to be produced in specific amounts.
• In multiple sclerosis, enzyme rate is not controlled and the immune system allows the enzymes to attack the nerves, resulting in paralysis.
• One common way of controlling metabolic reaction is using the end product of a metabolic pathway as a non-competitive inhibitor. 
• Metabolic pathway: Process composed of many different reactions, each catalysed by a different enzyme.
• This means the process controls itself, as the more product is produced, the more enzymes get inhibited, meaning less substrate binding. But once the end-product is needed, it can detach from the enzyme, allowing it to function again.

Biology: Chapter 3: Enzymes: Factors that affect enzyme activity

Biology: Chapter 3: Enzymes: Factors that affect enzyme activity

Course of a reaction

• In the beginning of the reaction, there are a large number of substrate molecules, so every enzyme has a substrate molecule to bind with, so rate of reaction is fastest at the beginning.
• But as the reaction continues, the substrate level goes down because they are being converted to products, so there are fewer substrates to bind to enzymes, reaction rate decreases, until it completely stops when all substrates have been converted to product.

• Initial rate of reaction: The rate at the beginning of the reaction, because rate is always quickest at the beginning. This can be found by drawing a tangent at the curve as close to time 0 as possible and calculating the gradient. 

Enzyme concentration

• Rate of reaction will increase with a higher enzyme concentration if there is always an excess of substrate concentration.
• Initial rate of reaction increases.
• If there is an limiting factor, eg. substrate concentration, the rate will not exceed after a certain point. For substrate concentration this is because even if you increase enzyme concentration, there will only be a limited amount of substrates to bind to the enzymes, and after the point where each enzyme has a substrate to bind to, excess enzymes will be useless because each substrate already has an enzyme to bind to. 
• Rate of reaction slowly decreases as substrate gets converted to product and in the end the total amount of product will be the same because the same amount of substrate was used.
• Effect of enzyme concentration can only be fairly measured at the beginning, because initial rate of reaction will vary the most with different enzyme concentrations. 

Substrate concentration

• Rate of reaction will increase with a higher substrate concentration if there is an excess of enzyme concentration.
• Initial rate of reaction increases. 
• There are more substrates for enzymes to bind to, limited to amount of enzymes for substrates to bind to.
• If more substrates are added than the amount of enzyme, each enzyme will have a substrate. The enzyme cannot work any faster, and substrates will need to wait for the enzyme to finish catalysing the first substrate.
• Enzyme will be working at it's fastest possible rate, known as Vmax. 

Temperature

• Reaction is slower at low temperature: Less kinetic energy means molecules move slowly, so there are less collisions between enzymes' active site and substrates.
• Reaction speeds up as temperature increases: There is more kinetic energy, so molecules move faster therefore there are more frequent collisions.
• However, at a certain temperature, enzyme will denature and stop working: Above a certain temperature, there is a large amount of kinetic energy, which also means a large amount of Vibrational energy. The structure of the enzyme molecule vibrates so much that some of the bonds holding the precise 3D shape of the enzyme molecule, especially the hydrogen and ionic bonds, start to break, This changes the shape of the enzyme, and therefore the shape of the active site, and substrates will no longer be able to fit into the active site. This is called denaturing, and is often irreversible.
• Optimum temperature: Temperature that the enzyme works best and fastest in. Often the temperature before the enzyme starts denaturing.
• In the human body, the optimum temperature of enzymes is our body temperature (37C), however, enzymes in different conditions will have different optimum temperatures.

pH level

• pH level: Amount of hydrogen ions in the solution. The lower the pH, the higher the hydrogen ion concentration (H+). The higher the pH, the higher the Hydroxide ion concentration (OH-). Measure of acidity and basicity. 
• Hydrogen and hydroxide ions can interact with the R groups of amino acids by affecting the ionisation (charges) of the group. 
• This affects the ionic bonding between groups, which can alter the 3D structure of the enzyme molecule, therefore also altering the shape of the active site. 
• Small differences in pH are reversible because the bonds can be reformed, However, a pH that is very different from the optimum pH of the enzyme can denature the enzyme.
• Optimum pH value: When the hydroxide and hydrogen ions positively  affect the bonds in the enzyme in such a way they make the active site more suited to the shape of the substrate.

Biology: Chapter 3: Enzymes: Basics

Biology: Chapter 3: Enzymes: Basics

• Enzyme: Protein molecules that act as biological catalysts.
• Biological catalyst: Molecule which speeds up a chemical reactions and remains unchanged at the end of the reaction.

Features of enzymes

• Intracellular: Enzymes that operate within cells.
• Extracellular: Enzymes secreted by cells and catalyse reactions outside cells.
• Globular: Hydrophilic R groups on the outside - Soluble
• Active site: Region (cleft or depression) that another molecule can bind to.
• Substrate: Molecule that binds to enzyme
• Enzyme-substrate complex: Binding of substrate and enzyme through temporary bonding between the R groups of the enzyme's amino acids and the substrate.
• Product: What you're left with after substrate binds with enzyme - Product of the reaction
• Anabolic: Making bonds
• Catabolic: Breaking bonds 

Induced fit

• Lock and key hypothesis: Each type of enzyme is specific to only one type of substrate; only one type of substrate fits in each type of enzyme's active site. However, this has been shown to be not exactly accurate, but instead enzymes and substrates have an induced fit.
• Induced fit: Enzyme, and sometimes substrate, can change shape slightly as the substrate enters the active site to ensure a perfect fit.

• Activation energy: Energy needed before a reaction occurs 
• Many necessary substrates in the body need a higher temperature than 37C before they can react, but it is impossible for us to raise our body temperature that high. 
• Enzymes lower the activation energy without increasing the heat by holding the substrates or substrate in such a way (physically breaking the bonds) they catalyse or by adding another chemical (H20 for hydrolysis/ ions).

Examples of enzymes

• Lactase: Breaks lactose into glucose and galactose. Found in the small intestine.
• Catalase: Breaks Hydrogen Peroxide into water and oxygen. Found in all living organisms.

Biology: Chapter 2: Biological molecules: Proteins

Biology: Chapter 2: Biologica molecules: Proteins

Hydroxyl group

Carboxyl group

Amino group

Sulfhydryl

Methyl group

• Proteins are an extremely important class of macromolecules. 
• Proteins make up 50% of the dry mass of most cells.
• Some of the many functions of proteins are as hormones, enzymes, antibodies, oxygen carrying pigments

Amino acids

• Structure: Central carbon atom bonded to an amine group and a carboxylic acid group (-COOH-) and a Hydrogen.

• The R group is what makes every amino acid different.
• 20 amino acids with different R groups occur naturally in proteins of living organisms
• Many new ones have been synthesized in laboratories

Peptide bond

• Covalent bond between two amino acids
• One amino acid loses a hydroxyl group (-OH-) from its carboxylic acid group (-COOH-) 
• The other loses a hydrogen from its amine group (-NHH-)
• Carbon of 1st amino acid bonds with nitrogen from amine group of the 2nd.
• Condensation reaction - H20 is removed
• Dipeptide - Two amino acids bonded by a peptide bond
• Polypeptide - Many amino acids linked by a peptide bond

• Ribosomes - Site where amino acids join together to form polypeptides - controlled by enzymes
• Peptide bond can be broken by adding H20 - hydrolysis - digestion of protein in stomach and small intestine

Primary structure

• Sequence of amino acids in a polypeptide chain
• Polypeptide can consist of several hundred amino acids linked by a peptide bond
• A change in one amino acid can completely alter the polypeptide properties

Secondary structure

• Structure of a protein molecule due to regular coiling/folding of the polypeptide chain of amino acids eg. alpha helices or beta pleated sheets
• Amino acids in a polypeptide chain have an effect on each other even if they are not directly next to each other 
• Oxygen from -CO- group of one amino acid bonds to hydrogen of -NH- group of the amino acid four places ahead of it. 

• Easily broken by high temperatures and pH changes
• Some proteins/ parts of proteins have no regular arrangement - depends on R groups of amino acids present therefore what attractions occur

Tertiary structure

• Compact structure of 3D coiling of the already-folded chain(secondary structure) of the amino acids. 
• The secondary structure (folding) of the amino acid chain (alpha helix or beta pleated sheet) coiled into a 3-dimensional (3D) structure
• Although it may look random and disorganized, the shape is very precise for each protein and is held in shape by four different types of bonds between amino acids in the chain.

1. Disulfide bonds - Strong double covalent bond formed between the sulfurs of two cysteine molecules (S=S)
2. Ionic bonds - Bond between two oppositely charged R groups (NH3+ and COO- groups). Can be broken by pH changes.
3. Hydrogen bonds - Between strong polar groups eg. -NH-, -CO- and -OH- groups
4. Weak hydrophobic interactions - Between non polar R groups. Hydrophobic R groups are repelled by the watery environment around them and stick together, though these bonds are weak.

• The tertiary structure of a protein can be broken by heat - increasing the kinetic energy makes the molecules vibrate more, so bonds holding the structure in shape (which are mostly weak non-covalent bonds) are more likely to break, and therefore changing its shape. This is called denaturing.

Quaternary structure

• 3D arrangement of two or more polypeptide chains or a polypeptide chain and a non protein molecule
• Forms a protein
• Bonded by the same four bonds used in the tertiary structure

Globular proteins

• Proteins whose molecules curl up into a 'ball' shape.
• Usually curl up so that the non-polar, hydrophobic R groups point towards the centre of the molecule, away from the watery environment.
• Most globular proteins are soluble - hydrophilic R groups on the outside of the protein, therefore water molecules cluster around them.
• Enzymes are globular proteins

Haemoglobin

• Oxygen carrying pigment in red blood cells
• Globular protein
• Made of four polypeptide chains - quaternary structure
• Each chain is known as a globin
• Two of the haemoglobin chains are called alpha chains and made from alpha-globin, while the two other ones are made from beta chains and are called beta-globin.
• The hydrophobic R groups point inside while the hydrophilic R groups are on the outside.
• Hydrophilic R groups on the outside maintain the haemoglobin's solubility.
• Interactions between hydrophobic R group on the inside help maintain it's correct 3D shape.
• Sickle cell anemia: Glutamic (hydrophilic amino acid) on the surface beta-chain is replaced with Valine (hydrophobic amino acid) - non-polar R group on the outside makes it less soluble.
• Prosthetic group: Important part of a protein molecule not made of amino acids
• Each polypeptide chain has a prosthetic haem group
• Each haem group has an iron atom, which can bind with O2 (two oxygen atoms). 
• Therefore a complete haemoglobin molecule can bind with 4 oxygen molecules (8 oxygen atoms) at one time since there are four polypeptide chains. 
• Haem group is responsible for colour of haemoglobin, depending on whether iron atoms have combined with oxygen. 
• Oxyhaemoglobin - When the iron atoms are combined with oxygen.

Fibrous proteins

• Form long strands
• Insoluble in water
• Usually have structural roles
• Keratin is a fibrous protein

Collagen

• Fibrous protein
• Makes up 25% of total protein in mammals - most common
• Structural protein 
• Consists of 3 polypeptide chains wound around each other in the shape of a helix (triple helix)
• Almost every third amino acid is glycine, the smallest amino acid - found on the inside, allows 3 strands to lie closer together and form a tight coil, since any other amino acid would be too large.
• Fibrils: Each 3 stranded collagen molecule interacts with other collagen molecules parallel to it. Covalent bonds form between R groups of amino acids next to each others, forming cross-links which hold many collagen molecules side by side forming the fibrils.
• Fibres: Strong bundle of many fibrils lying alongside each other.
• Collagen fibres line up according to forces they must withstand.
• Flexible but can withstand large tensile strength - withstand large pulling forces without stretching or breaking.
• Achilles tendon can withstand a pulling force of 300N

Biology: Chapter 2: Biological molecules: Lipids

Biology: Chapter 2: Biological molecules: Lipids

Carboxyl group

Hydroxl group

• Organic molecules which are insoluble in water.
• Esters formed by fatty acids combining with an alcohol.

Fatty acids

• Series of acids
• Contain acidic group (-COOH-) and long hydrocarbon tail (-CH-)
• Hydrocarbon chain is usually 15-17 carbon atoms long
• Some of the hydrocarbon tails have double bonds between the neighbouring carbon atoms       (-C=C-).
• Unsaturated: With double bonds -  do not contain maximum possible amount of hydrogen. Form unsaturated lipids. Double bonds make fatty acids and lipids melt more easily. Fatty acids/ Lipids with only one double bond are called monounsaturated, one or more double bonds are called polyunsaturated. Examples: Plants lipids - Oils eg olive oil 
• Saturated: Only single bonds - maximum possible amount of hydrogen. Examples: Animal lipids eg fats

Alcohols and Esters

• Alcohol: Organic molecule that contains a hydroxyl group (-OH-) attached to a carbon atom.
• Ester: Chemical produced in reaction between an acid and alcohol.
• Ester bond: Chemical link between acid and alcohol. -COOH- acid reacts with -OH- alcohol to form the ester bond -COO-. Condensation reaction. 

Triglycerides

• Fats and oils
• Most common lipid
• Glyceride: Ester formed by fatty acid bonding with the alcohol glycerol
• Glycerol: Alcohol with 3 hydroxyl groups; each of Glycerol's hydroxyl groups bond with a fatty acid through condensation
• Hydrocarbon 'tail' vary in length depending on fatty acids used.
• Insoluble in water but soluble in a few organic solvents eg. ethanol and chloroform 
• Hydrocarbon tails are non-polar (no uneven distribution of electrons) which means they are hydrophobic
• Energy reserves: Lipids are better for storing energy than carbohydrates because they have more carbon-hydrogen bonds - Lipids of one mass will yield more energy on oxidation than the same mass of a carbohydrate.
• Insulator against loss of heat: Stored around organs and under the skin
• Buoyancy for aquatic animals: Blubber
• Metabolic source of water: When lipids are oxidised in respiration they are converted to carbon dioxide and water, which is useful for animals in dry climates eg. the desert kangaroo never drinks water but instead relies on this process.

Phospholipids

• Special type of lipid
• One of the three fatty acid 'tails' is replaced with a phosphate group
• Phosphates are polar - dissolve in water (hydrophilic)
• One end of the lipid is soluble in water - The phosphate group is hydrophilic and makes the head of the phospholipid hydrophilic, but the two remaining fatty acid tails are hydrophobic.
• Used to form membranes

Social psychology: Case study 2: Prison Simulation

Social psychology: Case study 2: Prison Simulation

Author: Haney, Banks and Zimbardo (1973)

Key term: Prison simulation

Background/ context: High recividism ( re-offending) rates mean that prison does not act as a deterrent for crime and neither do they rehabilitate most inmates. What makes prison so bad? Prisoners are stereotyped as bad people, but can the dispositional assumption be tested? If good, regular people are put in a prison environment would the situational approach turn them into bad people or would they leave remaining good?

Dispositional: Behaviour is caused due to individual personality or characteristics - their disposition. 

Situational: Cause of behaviour is caused by a feature of characteristic of the situation.

Aim/Hypothesis: Test whether the behaviour of non-prisoners (regular law-abiding citizens) in a simulated prison environment is more affected by their disposition than the situation. "The deplorable conditions of our penal system and it's dehumanising effects upon prisoners and guards is due to the 'nature' (disposition) of people who administrate and of the people who populate it, or both."

Zimbardo believed that prisoners had a high recividism rate and lack of rehabilitation due to disposition rather than situation.

Setting/Apparatus: 

• For arrest of participants selected as prisoners - Police, police car and police station
• Prison construction in basement of psychology department at Stanford University
  Consisted of 3 small cells (6 x 9 feet) made of converted laboratory rooms
  Solitary confinement was a small unlit broom cupboard (2 x 2 x 7 feet)
  Corridor used as yard
• No windows, no clocks, prisoners had no contact with outside world
• Cells had a mattress, sheet and pillow per person
• Intercom set up to record conversations

Uniforms: Promote feeling of anonymity in both groups and deindividuality

Guards:

• Plain khaki shirt and trousers, whistle and wooden baton - feeling of superiority/ military attitude
• Reflecting sunglasses - Impossible to make known eye contact with a prisoner - Loss of individuality

Prisoners: 

• Loose fitting muslin smock with ID number on front and back - loss of individuality
• No undergarmets - Make the prisoners assume more feminine postures - emasculation and humiliation (loss of masculinity)
• Ankle chain, cap made from a stocking and rubber sandals - Feeling of inferiority, ankle chain makes them feel oppressed and loss of individuality

Participants/Sampling technique: Advert put in newspaper for volunteers to take part in "Study on psychological effects of prison life". Paid $15 per day (unethical - cash payment and possible deception). 24 males selected from 75 who replied, but only 21 male college students from Stanford (weakness - lack of variety - all american male students - generalization) were actually involved in experiment since one backed out and two were standby. Psychometric tests conducted to ensure participants had good mental and physical health and had not committed any crime. Self-selecting because people volunteered.

Participants randomly allocated role of prisoner or guard. All signed a contract guarenteeing adequate diet, enough clothing, appropriate clothing and medical care.

Procedure

• Induction for guards: Guards met one day prior to induction for prisoners to meet the research team which consisted of the 'superintendent' of the prison (Zimbardo himself - researcher) and the warden (research assistant). (weakness - Researcher should not participate in experiment.) Guards were told they wanted to recreate a prison environment ethically. They were told their main task was to "maintain a reasonable amount of order within the prison necessary for its effective functioning". Given tasks such as shift logs, reporting any criminal incidents and administration of meals to prisoners.Involved in placing cots in the cells. They were only given minimal guidelines on how to 'act' in order to capture genuine reactions to the simulation.Prohibited to use physical punishment or aggression.

• Induction for prisoners - Arrest: 'Arrested' from their house without prior warning along with help from Palo Alto city police department (unethical - no informed consent).
  A real police officer charged the participants for suspicion of either armed robbery or arrest, told them their legal rights, handcuffed them, searched them and took them to the police station. At the police station they were fingerprinted, had a file prepared and kept in a detention cell. The police acted as though they were dealing with a real criminal and did not answer any questions about the study.
  Each prisoner was then taken to the prison simulation where they were stripped, deloused (sprayed for lice) and made to stand alone naked - humiliate and make them feel subservient (inferior.)Given their uniform and ID number and had their picture taken.

• Prison life: Guards read the rules of the prison (devised by guards with the warden) and prisoners were told to memorize the rules.
  -Prisoners would only be referred by their uniform ID number.
  -Prisoners given 3 basic meals
  -Prisoners were allowed 3 supervised toilet visits
  -Prisoners given two hours for privileges eg. writing or reading
  -Work assignments given to prisoners so they could earn their $15 a day
  -Prisoners were lined up 3 times a day for a count - checking all prisoners were present, and they memorized their ID numbers and prison rules
  -Two visiting periods were scheduled per week (experimented lasted only 6 days)

Results

• Both sets of participants became more and more negative.
• Total of 5 prisoners had to be released because of extreme emotional depression; symptoms were seen on day 2 for 4 of the prisoners.
• 5th prisoner had to be released because he developed a psychometric rash (rash from stress)
• Experimented was terminated after 6 days because guards were becoming worse in their treatment of prisoners
• Prisoners rebelled on the 2nd day by removing their caps, tearing off their ID numbers and barricading themselves in their cells. The guards retaliated by forcing prisoners out of their cells, stripping them naked and locking some of them in solitary confinement.
• Recordings of private conversations of prisoners showed 90% of their conversations centered around prison life.
• Prisoners became more submissive while guards got more cruel. 
• Mundane realism - Participants truly believed they were stuck in the prison
• Guards started using psychological tactics to regulate prison - solitary confinement as punishment, punishment for all prisoners for the mistake of one, and privilege cells for prisoners who behaved well. This dissolved prisoner cohesion - Prisoners distrusted each other and stopped working as a team. 
• Guards became increasingly aggressive with their freedom to control - one guard locked a prisoner in solitary confinement (which was against the rules) and turned the prisoners rights into privileges.
• Prisoner #8612 left and was replaced with a replacement who went on a hunger strike to protest the treatment of inmates, but was seen as a threat by other inmates instead of trying to help.

• Pathology of power: 
  
  • Guards became increasingly aggressive with their freedom to control - one guard locked a prisoner in solitary confinement (which was against the rules) and turned the prisoners rights into privileges.
  • Aggression appeared to get stronger at the beginning when prisoners showed defiance.
  • The most hostile guards became the leader - one guard was so harsh he was nicknamed "John Wayne".
  • Guards started coming in when they were not on shift because they were so involved and enjoyed their extreme power. 
  • Some dispositional effects: Guards were either tough but fair and followed rules, never punished the prisoners and helped them, or extremely hostile and caused degradation and humiliation whenever possible.

  
  
• Pathological prisoner syndrome:
  
  • Mental state of prisoners went down rapidly
  • When their rebellion failed, they tried using subtle methods like setting up a grievance committee. When all efforts of rebellion failed they just accepted their fate and turned to self-interest at the expense of group behaviour.
  • Destroyed, isolated and obedient
  • Elements of pathological prisoner syndrome were seen:
  • Loss of personal identity: Prisoners felt deindividuated, referred to each other by ID number instead of name and rarely spoke about outside life.
  • Arbitrary control: Increased difficulty in coping with increasing stronger control and unpredictable unfairness by guards, the prisoners just accepted their fate and went along with everything - learned helplessness.
  • Dependency and emasculation: Prisoners had to depend on guards for everything from toilet breaks to cleaning their teeth (they were handcuffed and blindfolded), These became privileges and required permission. Smocks resembled dresses and without underwear the prisoners had to sit like girls. Guards taunted prisoners and called them 'sissies' or 'girls', emasculating the prisoners. 

  
  

Conclusion: Situation has a bigger effect on behaviour than disposition. People adapt what they think they should do in a situation instead of acting based on their individual thinking. Bad people do not make bad places but instead it is the other way round.

Strengths:

• Validity due to high degree of control - Laboratory experiment - 'Healthy, normal citizens' to exclude EV of disposition, guards and prisoners roles randomly assigned.
• Realistic setting: Participants began to believe they were really in an prison environment - arrest of prisoners, prison procedure, uniforms, prison environment - could show the experiment has some ecological validity
• Qualitative data - Participants conversations and behaviour - provides rich, in-depth data
• Quantitative data - Videos, counted accounts of a particular behaviour seen in participants - provides more objective data

Weaknesses:

• Participants were aware they were in an experiment - could have affected their behaviour making the experiment invalid although the situation was said to have felt 'real'.
• Participants were paid $15 a day - which may have affected the participants behaviour so they receive their pay
• Only male subjects - generalization - invalid
• Difficult to replicate - unreliable
• Researcher bias - Zimbardo himself participated in the experiment (superintendent)

Ethics

• Prisoners suffered mental abuse, harassment and having to earn basic rights (eg. toilet visits) for 5 days which could have caused psychological damage.
• Right to withdraw - Participants may not have known they could withdraw since one prisoner spread a rumor they could not leave and Zimbardo did not tell them the rumor was false
• Deception - Participants allocated the role of prisoner were not told they would be arrested as induction

Social Psychology: Case study 1: Behavioural study of obedience

Social Psychology: Case study 1: Behavioural study of obedience

Author: Milgram (1963)

Key term: Obedience

Background/Context: Milgram believed that the holocaust had such a high mortality rate because "the Germans were different" (GADH) from the rest of society. He believed that extreme obedience to authority to the point of mass murder was a one-off, and he expected that in USA in the 1960s no one would obey if he created an extreme situation. 

Destructive behaviour: Orders from authority to cause harm to another person.

Aim/Hypothesis: To test the hypothesis that obeying the orders to murder was a 'one-off' thing and would not happen again. Milgram wanted to show that the germans had a basic character defect and were ready to obey obedience without question regardless of the orders demanded by the authoritive figure, which made Hitler able to commit the genocide of millions of jews. He believed that USA citizens in the 1960s would not obey the command to inflict critical pain onto another person - in this study, that US citizens would not give a harmful electric shock participants would give to a helpless man when ordered to by a scientist in a laboratory. 

40 psychologists predicted that less than 1% would administer the highest voltage. 

Method: Laboratory experiment - observation with questionnaire and interview at the end 

Design: There is no design because the experiment is a 'controlled observation' since there are no different conditions of the IV  - everyone did the same experiment

Participants/ Sampling technique: Advert placed in newspaper looking for volunteers for a study on "learning and memory". Participants would be paid $4 plus $0.50 for travel, though they were never told that payment was conditional on completing the study. (unethical - cash reward and deception). 40 males aged 20-50 of a variety of badckgrounds were selected. The sample was self-selected because people volunteered.

Experimenters: 

• Experimenter: 31 year old biology teacher in a grey lab coat. 
• Mr. Wallace: 47 year old actor pretending to be 'learner' in participant pair. 

Stooge: Someone pretending to be a participant but is actually working in the experiment/ for the researcher. 

Controls:

• Procedure was the same for all participants
• Outfit worn by experimenter (grey lab coat)
• Mistakes made by Mr. Wallace as well as his reaction to the shocks were the same for all participants (pounding on wall at 300V)
• Prods:
  "Please continue."
  "The experimenter requires you to continue."
  "It is absolutely essential that you continue"
  "You have no other choice, you must go on"

Procedure:

1. When each participant arrived, he was introduced to "Mr. Wallace", who they believed to be another participant. The two men were told they were doing an experiment to investigate the effect of punishment on learning. (Unethical - Deception)
2. They were told that one of them would play the role of teacher or learner, and pulled slips of paper from a hat to choose which role they would play, but this was set up so Mr. Wallace would always be the learner.
3. Taken to another room where the learner Mr. Wallace was strapped to a chair and had electrodes attached to him, and the participant was shown the electric shock generator, which rose in 15 volt intervals, from 15V to 450V Participants were told the shocks could be extremely painful but not dangerous; they were both given 45V shocks to demonstrate.
4. The participant (in the role of teacher) was given word pairs to read out to test Mr. Wallace (learner/ stooge) on his recognition of which word pairs went together by pressing a button so it was displayed in teaching room. Every time Mr. Wallace got it right the next pair was presented, but each time Mr. Wallace made a mistake (which was delibrate) the experimenter (also a stooge, so mistakes were planned) ordered the participant to give a shock. The shocks were to increase by 15V for each mistake. No actual shocks were given to Mr. Wallace but the participant did not know this as there was a wall between the teacher and learner.
5. Up to 300V Mr. Wallace did not signal any response to the shocks. However, at 300V and 315V he pounded on the wall and asked to be let out. Afterwards he was silent and did not respond to anymore questions, which could suggest he was hurt, unconscious or dead.
6. When participants (teachers) turned to the experimenter for guidance, they were told to treat his silence as an incorrect response and continue to give the shocks. When the participants protested, the experimenter gave a series of  the verbal prods to encourage them to continue.
7. Participants were considered to have finished the experiment when they refused to give anymore shocks or reached the maximum at 450V. They were then interviewed and asked to rate the on a scale of 1-14 how painful the shocks were for Mr. Wallace. The participants were then debriefed and told the shocks were not real and Mr. Wallace was just an actor and was unharmed, and the real purpose of this study was to test obedience to authority. 

Results

• All participants administered up to 300V.
• 26 participants went up to the maximum 450V (65% of participants)
• 5 refused to go beyond 300V, 4 beyond 315V, 2 beyond 330V and 1 each at 345V, 360V and 375V,
• 14 participants refused
• Most participants showed signs of stress from their body language; sweating, lip biting, stuttering.
• 14 participant laughed nervously
• One had a seizure and the procedure was stopped.
• Most participants protested, although the verbal prods by the experimenter was usually enough to make them continue administering shocks. (Diffusion of responsibility - responsibility supposedly in experimenter's hands)
• Participants rated how level of pain of the last shocks given to Mr. Waller to be 13.42 on a 1-14 scale 

Conclusion

1. People are much more obedient to destructive obedience than we think - majority of people will obey destructive orders
2. However they find obeying these orders highly distressing, though they obey despite their emotional responses. The situation triggers conflict between two ingrained tendences: to obey authority and not to harm people.

Strengths

• Laboratory experiment - High levels of control, can be replicated to test for reliability - Controls: Drawing of lots, timing of scripted responses, 15V progression - allows retest for reliability
• Laboratory experiment - High level of control - IV directly affects DV -
  Controls: Test shock, receiving prods from Mr. Waller at the same time for everyone, same scripted responses - Confidence that the situation of the experiment was the cause of the obedience levels.

Weaknesses

• Laboratory experiment - Artificial scenario - Lack of mundane realism - People are not normally asked to give electric shocks as negative reinforcement.
• Laboratory experiment - Artificial setting - Lack of ecological validity - People do not find themselves in a laboratory in front of a shock generator (although the experiment was repeated in different environments (eg. rundown office block) and with different procedures (eg. experimenter not physically in the room) therefore it could be said that there is some ecological validity but not in this single experiment.)
• Participants were paid $4.00, which may have affected their behaviour as this would have made participants less likely to withdraw due to pay received.
• Generalized - Participants were all male - cannot represent whole population

Ethics

• Deception
  - Participants volunteered for a 'learning and memory' study and were not told beforehand about the experiment. 
  -Participants (teachers) thought they were giving real electric shocks
• Debriefing 
  -Participants were debriefed at the end of experiment so they know they did not really harm anyone, and Milgram had a follow up with the participants 6 months after the experiment to see if they were having any psychological issues from the experiment
• Right to withdraw 
  - Prods given by experimenter although participant protests may have made it more difficult to withdraw because the participants were unclear about whether they had a right to withdraw 
• Psychological damage
  -Participants were caused extreme stress and anxiety as well as tricked

English language: Language framework: Spoken language

Literary devices: Spoken language

Main two purposes

1. Convey meaning - Language as a means of clarification, so someone will understand you. Eg explain something or give orders or instructions.
2. Demonstrate attitudes and values - Offer opinions on subjects or get your point of view across.

External features that affect the spoken language 

1. Audience/ Person being addressed - Affects formality and content eg. friends = informal
2. Speaker's background - Affects word choices, accent, grammatical constructions, etc.
3. Location and purpose of text - Where the conversation is taking place and what's being talked about eg. speech at university about biology = formal 

• Formal: Used in situations such as talking to people you don't know well, at formal events (eg. job interview or tea party). Common for prepared and planned speeches. Uses more complex and mainly complete grammatical structures.
• Informal: Among friends or casual talk. Mainly colloquial language (spoken only), which is casual and familiar. Simpler and incomplete grammatical structure, simpler vocabulary and dialect features.

Individual speech

• Monologue: Conveys opinions, inner thoughts or experiences
• Can be scripted performance (speech, show) or individual speaking for longer than normal.
• Can be directed at individuals with no spoken contribution
• Prepared or spontaneous

Dialogue

• Conversation involving two or more people
• Use language to interact with each other
• Scripted: Actors in a movie/ tv show
• Spontaneous: Between friends - dialogue speakers respond to different cues and contexts that come up in the conversation to keep it going

5 Functions of spoken language

1. Interactional language: Language of informal speech, Has a social function. Purpose is to develop relationships between speakers. eg exchanging personal information and asking questions to keep the interaction going.
2. Referential language: Provides reader with information. Refers to objects and abstract concepts. Speaker assumes knowledge from listener, and the listener has to understand the context eg. The car will pick you up there at 5. 
3. Expressive language: Highlights speakers emotions, feelings and attitudes. Shows speakers judgement or feelings about a person, situation or event.
4. Transactional language: Getting information or making a deal eg. buying or selling. Specific purpose = driven by needs or wants instead of sociability eg. how much are those shoes
5. Phatic language: "Small talk", Used for social purposes instead of conveying serious information eg. asking about the weather to initiate a conversation.

Prepared speech

• Planned 
• Lexis: Standardised and formal, words choices are sophisticated and technical. 
• Grammar: Follow standard grammar rules, don't have many contractions (corrections), pauses controlled by punctuation.
• Formality/ Audience: Aimed at an audience, usually language chosen to persuade audience in some way or create an impact. Usually address audience directly (inclusive pronouns eg, we or you) to maintain interest. Often formal to create feeling of prestige (higher profile).
• Examples: political speeches

Spontaneous speech

• Unplanned
• Lexis: Non-standard, includes slang and dialect forms.
• Grammar: Non-standard agreements, non-standard/ irregular tenses, double negatives (eg. we done it, we was planning to)
• Formality/ Audience: Only meant for speakers involved. Formality dependent on situation (eg. strangers = more formal)

Similarities: 

• Non verbal communication eg. body language
• Discourse: Themes and ideas, beginning, middle and end

Features of spontaneous speech

• Ellipses: Part of the grammatical structure removed from the sentence without affecting the understanding eg. (Are) You coming?
• Phatic expression: Initiating conversation eg. Nice weather we have
• False start: Speaker changes train of thought halfway through conversation, and begins utterance again eg. On saturday er tomorrow night
• Back-channelling: Feed back from the listener to show the speaker he's understood eg. I see or can be non verbal eg. nodding your head
• Deitic expression: Pointers that refer the listener backwards or outside the text . Listener needs to understand the context. eg. this, that, here, there
• Non-fluency features: Interrupt the flow of speech. Hesitation, repetition, interruptions and overlaps eg. er, um 
• Elision: Slurring words together eg. gonna instead of going to
• Hedging: Uncertainty in conversation or weaken force of what you're saying eg. probably,
• maybe, perhaps

Conversation features

All conversations

• Opening
• Response
• Adjacency pairs: Short exchanges of speech that follow predictable patterns eg. How are you? I'm fine thanks
• Signalling closure: Verbal or non verbal gestures that close the conversation eg. Bye

Individual speakers

• Switching and turn taking: Speaker invites other people to talk switching the conversation by pausing or making a emphatic statement eg. How about you? Domineering speakers might ignore this meaning other speakers have to interrupt or stay silent.
• Tag questions: Attached to the end of statements and invite responses or feedback from listeners. eg. right? isn't it? Could be because the speaker is trying to control the conversation or feels awkward.
• Topic shift: Changing the subject of the conversation to control conversation
• Feedback: Listeners give verbal/ non-verbal signs to show that they're listening eg. mm-hmm, yeah, nodding

Techniques at different stages of a conversation

1. Initiating conversation: Showing an interest, offering contributions, phatic expressions and questioning for unfaimiliar people eg. tag questions to initiate response
2. Sustaining conversation: Following adjencency patterns and turn taking rules, giving feedback sustain the conversation and show speaker empathy by shared interests and opinions.
3. Ending conversation: Phatic expressions are used to signal closure so people do not appear rude eg. I should get going. There are also non verbal ways such as standing up or increasing the distance.

• Techniques in formal situations: Defined power relationship eg. interviews. Prepared situations with a specific subject and level of formality.
• Techniques in informal situations: Less prepared and involve a variety of topics but still controlled by domineering speakers than inhibited speakers.

Biology: Chapter 2: Biological molecules: Carbohydrates

Biology: Chapter 2: Biological molecules: Carbohydrates

 Sugar quiz

Polysaccharide quiz

• General formula for a carbohydrate is Cx(H2O)y
• Contain elements Hydrogen, Carbon and Oxygen
• Saccharide: Sugar

Common groups:

     Hydroxl Group

        Carbonyl Group

Monosaccharides

• Single sugar molecule
• General formula: (CH2O)n
• All monosaccharides end with -ose eg. glucose, fructose, galactose
• Trioses: 3 carbons, Pentoses: 5 carbons, Hexoses: 6 carbons.
• Source of energy, due to large amount of C-H bonds.
• Building blocks for larger molecules

Molecular and structural formula

• Molecular formula for hexose: C6H12O6
• Below is the structural and ring structure of glucose

• Pentoses and Hexoses have carbon chains long enough to close in on itself and form a more stable ring. Above is an example of a glucose ring structure. 
• Carbon 1 joins to Carbon 5, leaving Carbon 6 out of the ring.
• The hydroxl group in glucose, -OH, can be above or below Carbon 5.
• α Glucose (alpha): -OH is below the ring
• β Glucose (beta): -OH is above the ring
• These are called isomers (two forms of the same chemical).

Disaccharides and Glycosidic bond

• Disaccharides: Two monosaccharides joint together  by condensationeg. Maltose (glucose + glucose), Sucrose (glucose + fructose)
• Condensation: Two Hydroxyl (-OH) groups line up alongside each other. One combines with a H atom from the other to form a H20 molecule, which is the waste product of the reaction.
• The Oxygen becomes the bridge between both molecules, holding them together. This is called a glycosidic bond.
• The reverse of this is called hydrolysis.

Polysaccharides

• Polymers whose subunits (monomers) are monosaccharides, bonded by glycosidic bonds.
• Final unit can be several 1000 monosaccharides long, forming a macromolecule.
• Not sugars
• Energy storage unit for monosaccharides (glucose), since glucose itself cannot be stored therefore is converted into polysaccharides, which are convenient - compact and inert

Starch

•     Mixture of two substances – Amylose and amylopectin
•    Commonly found in chloroplasts – energy storage
•    Never  found in animal cells
•  Amylose: Long, unbroken chain of alpha α glucose molecules bonded by a glycosidic bond through condensation at 1,4 linkages.
• 1,4 linkages: The glycosidic bond is formed between the Carbon 1 of one glucose molecule and Carbon 4 of the next.
• Chains are curved and coil into helical structures – more compact.
•  Amylopectin: Also made of 1,4 linkages, but has shorter chains than amylose and has branches.
•  Branches: Formed by 1,6 linkages – Carbon 1 of one glucose molecule forming a bond with Carbon 6 of another.

Glycogen

•   Similar to Amylopectin – Chains of α glucose made of 1,4 linkages and 1,6 linkages, forming branches.
• More branched than amylopectin
• Clump together to form granules – visible in liver and muscle cells
• Energy storage for animal cells

Cellulose 

•  Structural role – Mechanically strong molecule
•  Polymer of beta β gluclose instead of alpha α glucose.
• In beta glucose, the –OH attached to Carbon 1 is above the ring, but on Carbon 4 it is below the ring
• This means every 2^nd beta glucose in the chain needs to rotate 180 degrees (upside down) to be able to form a glycosidic bond with the glucose in front.
• Strong molecule - Hydrogen bonding between different cellulose molecules 
• The hydrogen bonds are individually weak, but many can form due to large number of Hydroxl (-OH) groups
• Around 60-70 celluolose molecules tightly crosslink to form Microfibrils
• Microfibrils hydrogen bond together to form bundles called Fibres
• Celluloe fibres have high tensile strength but are still freely permeable 
• Found in cell wall - provide support for plant and helps it withstand the large pressures from osmosis