Chapter+8

Page 83 //search terms for info. on this topic is upper and lower critical temperature;//
1. Respiration rate increases with decreasing temperature below 12 C; temperature changes between 12 C and 33 C have no effect on respiration rate; As temperature climbs above 33 C, respiration rate begins to increase (sharply); 2. Bird is trying to maintain temperature homeostasis; Respiration generates waste heat; Rise in metabolic rate undertaken to preserve core temperature; Bird may increase motion as well to preserve core temperature; 3. increase in metabolic rate linked to activities designed to keep cool; such as evapourative cooling through increased ventilation rate; 4. random/experimental error; variation in surface area of birds effects temperature homeostasis;

1. 15/16 g total mass loss; __560-544;__ 13 1.2 g per day;
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= = 2. alcoholic fermentation; CO2 is the waste product; CO2 release leads to mass loss;

3. population growth of yeast/more yeast plants respiring; positive feedback/increasing amounts of co2 from higher population leads to lower solubility/higher rate of release; waste heat decreases CO2 solubility ;

4. substrate has run out; death of yeast (from high alcohol); = =

1. a) At time zero, glucose concentration is 42g/l; Glucose concentration falls gradually between 0 and 5 hours; Sharp decline in glucose concentration between 5 and 10 hours; At 10 hours, glucose concentration is close to 0g/l; As time increases, rate of uptake of glucose increases. . b) Between zero and 5 hours, decline in glucose concentration correlates with a gradual increase in yeast population; After 5 hours, rate of growth of yeast increases and rate of uptake of glucose increases correspondingly; Between zero and ten hours, ethanol production matches yeast growth; At 10 hours, yeast growth slows as glucose runs out; After 15 hours, rate of yeast growth increases as ethanol concentration decreases.
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2. Estimates based on the small graph: a) 5 hours = 0.02A, 10 hours = 0.08A therefore yeast growth = 0.06A = = b) 10 hours = 0.08A, 15 hpurs = 0.10A therefore yeast growth = 0.02A

3. 5 - 10 hours represents exponential growth phase and fastest uptake of glucose; 10-15 hours represents stationary phase - growth limited by space or resources (e.g. glucose availability); After 10 hours, rate of growth decreases as glucose concentration decreases

4. Help me out with this one... Increasing levels of ethanol between 0 and 15 hours suggests high anaerobic activity; Beyond 15 hours, ethanol decreases - aerobic respiration produces water, reducing ethanol concentration?; Beyond 15 hours, is ethanol being used as an energy source to replace the depleted glucose?


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