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    (Original post by 19941994)
    Coenzyme A


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    thats a coenzyme.
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    (Original post by iesians)
    thats a coenzyme.
    Um citrate?


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    (Original post by ishtarbb)
    Sorry but can you send them to me as well? i mean if you not gonna upload them here

    im a private student and got really few resources
    thank you so much!
    http://www.scribd.com/doc/89838095/S...Stafford-Final

    check those out! there amazing!
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    (Original post by moodychopin)
    [u.al[/url]

    check those out! there amazing!
    thanks
    Q. describe how to investigate the rate of respiration practically (5 marks)
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    And look at this these are two really good notes posted by someone else for the article


    SUMMARY
    1.Brown adipose tissue (BAT) is activated by cold temperatures. Could this help us with weight loss?
    2. Obesity is on the increase in the UK because of excess white adipose tissue (WAT). This can lead to a number of health risks.
    3. Body dissatisfaction had been linked to eating disorders.
    4. fMRI has been used to study the brain response to media images of thin and fat people.
    5. When we are self-reflective, the activity within the medial prefrontal cortex (mPFC) is increased.
    6. Brains of women respond to both images and the printed word, but men do not respond the same way.
    7. In females with eating disorders mPFC and amygdala (brain area associated with emotional responses) activated.
    8. mPFC responsible for gender differences in processing words and images, and susceptibility to eating disorders.
    9. Restricted calorie diets (and increased stress) lead to more cortisol (adrenal gland hormone - its primary functions are to increase blood sugar; suppress the immune system; and aid in fat, protein and carbohydrate metabolism) release in females, causing higher levels of CHD, diabetes and cancer.
    10. Stress leads to over-compensation of calorie rich foods (in rodent studies)
    11. BAT - these cells have lipid in the form of droplets, not in one large (as in other fat cells)
    12. BAT has many mitochondria, and lots of UCP-1 (uncoupling protein that disrupts respiration at the electron transport system level, and so prevents the production of ATP, so energy is lost as heat instead of being stored.
    13. BAT cells are activated the SNS and thyroid hormones.
    14. The SNS is also activated by exposure to cold temperatures and ingestion of high caloric food.
    15. So BAT regulates Core Body Temperature and body weight by increasing energy expenditure.
    16. BAT is found in most small mammals, and newborns of larger animals. It was not thought to be present in adults of these animals.
    17. Babies have a large surface area to volume ratio so lose hear more easily - they are also unable to shiver.
    18. Lumberjacks have been found to retain BAT deposits in their neck region - the amount of BAT present relates to the length of time in cold conditions.
    19. BAT has also now been found in adults (neck region), with lean people having more BAT present in - so does it help against obesity?
    20. How can we stimulate BAT in us to help us lose weight - would it help if we were kept in cold conditions?
    21. BAT can be stimulated by high levels of thyroid hormones and drugs, but there are unpleasant side-effects.
    22. How can we increase the amount of BAT in us?
    23. A protein called PRDM 16 makes WAT precursor cells become BAT cells instead of WAT cells.
    24. Could PRDM 16 be used to transform stem cells into BAT cells, which can be transplanted to us?
    25. Diet affects gene expression.
    26. Disturbed expression of dopaminergenic genes has been identified in eating disorders.

    1. Using specific examples; discuss whether there is a correlation between the media and amount of body dissatisfaction.
    Examples For:
    • 5) University of Central Florida study; approx. half of 3 – 6 year old girls in the study said they were concerned with being fat. (No direct link- but media images could be influencing) Idea of diet pill usage increase (100% increase) in 15-17 year olds being an indicator of increased body dissatisfaction.
    • 6) 80% increase in young girls admitted to hospital with anorexia.
    • 7) Meta-analysis of 25 studies (likely to be reliable) concluded ‘body image was significantly more negative after view thin media images’.
    • 10) Hiroshima University study on healthy women: all subjects showed mPFC activation (associated with self-reflection/sub conscious thoughts) when presented with overweight images.
    • 12) Hiroshima study showed healthy women have PFC and amygdala (emotional reaction processing) ‘signicantly activated’ when presented with a self ‘fat image’.
    • 15/16) Harvard Medical School study evaluating the impact of television (main visual media source) on body satisfaction and disordered eating in adolescent girls.
    o Idea of traditional preference for full figure; low 12.7% with pathological scores for eating disorders, low/no dieting in adolescent females (implied; 15) ‘rare’), no self-induced vomiting
    o --- Increase in all above measures in 3 years since introduction of television suggests strong correlation. Eg; 16.5% increase in pathological eating disorders, 66% of subjects concerned with body image (not just limited to females), girls openly citing thin media figures as desirable / eqv, increase in self-induced vomiting to 11.3%.
    • 17) British study found ¼ UK adults is trying to lose weight either due to body dissatisfaction obesity.
    Against:
    • 11) Men showed no significant mPFC activation when [resented with overweight/ thin male images.
    • 13) Men have activated mPFC (amygdala deactivation also implied) when presented with unpleasant word stimuli concerning ‘heavy’ body image.

    2. Analyse and interpret the possible link between obesity and health issues, such as diabetes, CVD and cancer.
    • 3) ‘Obesity defined as a surplus of body fat which is detrimental to health’ around the waist/abdomen
    o Idea that if energy intake from food is greater than energy expenditure person will gain weight. (normally, fat –stored in the form of triglycerides)
     Reference to BMR (Basal Metabolic rate)
     Reference to PAL (physical activity level) needing to be taken into account
    • Idea that type 2 diabetes is caused long term high blood glucose levels
    o Relation to higher energy input than expenditure; leading to increased blood glucose levels.
    o Idea that insulin controls blood gluclose levels
    o Idea body cells do not produce enough insulin/ cells do not respond to insulin /eqv
    • Idea that CVD is a multifactorial condition.
    o So obesity is only one factor.
    o Triglycerides can form fatty acid plaques in the arteries
     Possibly leading to CVD / blood clots /death
     Or raising blood pressure and leading to atherosclerosis
    o Obese people unlikely to have appropriate diet; may have high blood cholesterol levels due to a diet high in saturated fats. Unlikely to be exercising an appropriate amount.
    o Idea that LDL DL ratio is a good indicator of CVD risk
    • Idea that body weight shouldn’t have a causal relationship with cancer
    o As cancer is caused by DNA mutation, caused by factors such as UV light/ Asbestos / X Rays / Carcinogens (eg in tobacco) (Environmental factors)
    • Idea that obesity is likely to be correlated with an unhealthy life style, people may also smoke/drink alcohol heavily.
    o These are factors that influence CVD and also cancer

    3. Lipids are biological molecules that are insoluble in water, but soluble in organic solvents, like ethanol. Triglycerides are lipids made out of three fatty acids and one molecule of glycerol joined via an ester bond. The glycerol molecules are all the same. Recall the variation between the fatty acids.
    • Fatty acids may be saturated/ unsaturated (presence of double bonds in the long carbon chain)
    • Lipids can be mono, di or tri-glycerides.
    4. When a triglyceride is broken apart by hydrolysis, how many components are found as products? Name them.
    • 3 fatty acids and 1 glycerol molecule

    5. Suggest reasons why it is likely that gender plays a role in susceptibility to eating disorders.
    • 23) Women may have evolutionary adaptations to try to acquire figures which seem to be attractive to males (subcutaneous fat /fat deposits around buttocks/hips – ideal for sexual selection). Hence, they could be more likely to look at the figures of other seemingly successful females, (eg media figures) as ideal for attracting a mate and improving chances of reproducing and passing genes on.
    • However, women may have different preferences in men (eg ability to provide for offspring) and hence, maintaining an ideal waist to hip ratio may not be as important for sexual selection in men. (This idea is backed up by lack of mPFC activation in men (11))
    o So women are more likely to take steps to change their figure and so would be more susceptible to developing an eating disorder.
    6. List key features of a good study used to determine health risk factors. Refer to examples in the text.
    • Use of a control group/individuals: 10) Study shows women images of both overweight and thin models; to see mPFC activation. This means mPFC activation when looking at overweight models can be attributed to the models being overweight and not another factor (eg knowledge that they are models) as otherwise looking at the thin models would also cause mPFC activation.
    • Epidemiological studies
    o Large sample size. eg 15) Harvard Group use the Fijian population (– no exact figure given) This gives more meaningful results.
    o Longitudinal studies: Harvard group only considers the changes in a 3 year period.
    • Methodology must be repeatable. Eg 7) multiple studies on the effect of experimental presentation of thin media images on body satisfaction
    7. Analyse and interpret data about the threats of eating disorders.
    • Occurrence of eating disorders on the rise (in England): 6) 80% rise in the last decade in number of girls admitted to hospital with anorexia.
    o Mortality rate of 10-20%. Anorexia causes death due to heart complications. Eg. Bradycardia, where the heart beats abnormally slowly (<60Bpm). This is because the heart muscles are starved of certain electrolytes due to a reduction in fluid and mineral levels. A precise electrolyte balance is needed to maintain correct electrical currents for heartbeat.
    • Eating disorders that restrict calories to under 1200kcal/day (18)) increase total cortisol output in females. This leads to a number of threats including; higher blood pressure, suppressed thyroid function, impaired immunity, increased abdominal fat which further lead to conditions such as cancer, CVD and diabetes.
    • 52) Anorexia prevalent in the UK, 1.4M females with eating disorder 10% anorexia.
    o Any logical argument about how this is a significant proportion of the total UK population (Approx 62M)
    • Logical argument about how perceived risk and actual risk are different. Eg. People may not understand the biological effects of severe dietary restriction.
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    oops sorry here's the second one


    SUMMARY
    1.Brown adipose tissue (BAT) is activated by cold temperatures. Could this help us with weight loss?
    2. Obesity is on the increase in the UK because of excess white adipose tissue (WAT). This can lead to a number of health risks.
    3. Body dissatisfaction had been linked to eating disorders.
    4. fMRI has been used to study the brain response to media images of thin and fat people.
    5. When we are self-reflective, the activity within the medial prefrontal cortex (mPFC) is increased.
    6. Brains of women respond to both images and the printed word, but men do not respond the same way.
    7. In females with eating disorders mPFC and amygdala (brain area associated with emotional responses) activated.
    8. mPFC responsible for gender differences in processing words and images, and susceptibility to eating disorders.
    9. Restricted calorie diets (and increased stress) lead to more cortisol (adrenal gland hormone - its primary functions are to increase blood sugar; suppress the immune system; and aid in fat, protein and carbohydrate metabolism) release in females, causing higher levels of CHD, diabetes and cancer.
    10. Stress leads to over-compensation of calorie rich foods (in rodent studies)
    11. BAT - these cells have lipid in the form of droplets, not in one large (as in other fat cells)
    12. BAT has many mitochondria, and lots of UCP-1 (uncoupling protein that disrupts respiration at the electron transport system level, and so prevents the production of ATP, so energy is lost as heat instead of being stored.
    13. BAT cells are activated the SNS and thyroid hormones.
    14. The SNS is also activated by exposure to cold temperatures and ingestion of high caloric food.
    15. So BAT regulates Core Body Temperature and body weight by increasing energy expenditure.
    16. BAT is found in most small mammals, and newborns of larger animals. It was not thought to be present in adults of these animals.
    17. Babies have a large surface area to volume ratio so lose hear more easily - they are also unable to shiver.
    18. Lumberjacks have been found to retain BAT deposits in their neck region - the amount of BAT present relates to the length of time in cold conditions.
    19. BAT has also now been found in adults (neck region), with lean people having more BAT present in - so does it help against obesity?
    20. How can we stimulate BAT in us to help us lose weight - would it help if we were kept in cold conditions?
    21. BAT can be stimulated by high levels of thyroid hormones and drugs, but there are unpleasant side-effects.
    22. How can we increase the amount of BAT in us?
    23. A protein called PRDM 16 makes WAT precursor cells become BAT cells instead of WAT cells.
    24. Could PRDM 16 be used to transform stem cells into BAT cells, which can be transplanted to us?
    25. Diet affects gene expression.
    26. Disturbed expression of dopaminergenic genes has been identified in eating disorders.
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    (Original post by ghogho)
    cuz the nerve fibre cnt accept a stimuli except at the resting stage this to make sure that the impulse move only in one direction
    look up the absolute and relative refractory periods
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    (Original post by I.LoveSyria.Aleppo)
    no,there's no Jan 11
    and no Jan 12
    even if you go onto the grade boundaries for Jan 2012, there's no Unit 5, only for Unit 1,2 and 4

    trust me
    LOL there is a jan 12 paper i did it last evening
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    (Original post by EmilyElectrik)
    LOL there is a jan 12 paper i did it last evening
    and jan 11 :mmm:
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    (Original post by iesians)
    name an enzyme used in Krebs cycle ?
    ATPase to convert ADP and Pi into ATP
    well i think so but nt sure
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    (Original post by This Honest)
    and jan 11 :mmm:
    she thought that this thread was for AQA not EDEXCEL:elmo:
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    For the pre release questions are we supposed to quote directly from the article or use our own words when answering the questions?
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    (Original post by ghogho)
    ATPase to convert ADP and Pi into ATP
    well i think so but nt sure
    thats NOT krebs cycle.
    answer is dehydrogenases. to transfer hydrgoen form compunds to NAD and FAD
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    (Original post by iesians)
    thats NOT krebs cycle.
    answer is dehydrogenases. to transfer hydrgoen form compunds to NAD and FAD
    aha ok thx for correcting my ans...................
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    (Original post by iesians)
    thats NOT krebs cycle.
    answer is dehydrogenases. to transfer hydrgoen form compunds to NAD and FAD
    I thought it was asking for 1 particular enzyme? Dehydrogenases are a group of enzymes, so would decarboxylases also be correct, as they are ezymes responsible for removing CO2? I didn't think we had to know the specific enzymes - only phosphofructokinase as the rate determining enzyme for respiration (which phosphorylates the hexose-phosphate in glycolysis).
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    (Original post by ghogho)
    ATPase to convert ADP and Pi into ATP
    well i think so but nt sure
    no ATPase hydrolyses ATP into ADP and Pi. ATP synthase is used to make ATP from them two in the process called oxidative phosphorylation. the movement of H+ ions (chemiosmosis) causes the generation of ATP using ATP synthase.
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    (Original post by medicinemm)
    I thought it was asking for 1 particular enzyme? Dehydrogenases are a group of enzymes, so would decarboxylases also be correct, as they are ezymes responsible for removing CO2? I didn't think we had to know the specific enzymes - only phosphofructokinase as the rate determining enzyme for respiration (which phosphorylates the hexose-phosphate in glycolysis).
    yup ! decarboxylases is righteo too !!

    never hear dof phosphofr.......wa ??!
    explain its function please
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    (Original post by medicinemm)
    I thought it was asking for 1 particular enzyme? Dehydrogenases are a group of enzymes, so would decarboxylases also be correct, as they are ezymes responsible for removing CO2? I didn't think we had to know the specific enzymes - only phosphofructokinase as the rate determining enzyme for respiration (which phosphorylates the hexose-phosphate in glycolysis).
    phosphofruct etc is nowhere in my snab text book...
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    (Original post by ghogho)
    she thought that this thread was for AQA not EDEXCEL:elmo:
    :rofl3: awww silly girl
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    Does anyone know ALL of the core experiments we should know for Unit 5?

    e.g. The woodlice and measuring oxygen uptake..

    There's other ones that I can't remember?

    Thanks!
 
 
 

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