Topic 4: Bioenergetics

Question 1

Explain what is meant by the lock and key mechanism

Answer 1

Substrate binds to active site of enzyme
both are complementary to each other so form enzyme-substrate complex
Bonds are broken which result in smaller molecules being formed and enzyme product produced

Question 2

Explain how the pregnancy test strip works to show a positive result
urine passes through reaction zone

Answer 2

HCG hormone binds to the mobile HCG antibody (in the reaction zone)
(passes up the stick) HCG hormone binds to the immobilised HCG antibodies in
the results zone
(the other) antibodies which do not attach to HCG bind to antibodies in control
zone
blue dye appears in both control and results zones (to show
positive result)

Question 3

plant

Answer 3

(nitrate deficiency ) stunted growth
(magnesium deficiency ) yellowing of leaves

Question 4

compare anaerobic respiration in a yeast and animal cell

Answer 4

yeast produces ethanol but muscles produce lactic acid
yeast produces CO2 but muscles do not
both release small amounts of
energy

Question 4

compare anaerobic respiration in a yeast and animal cell

Answer 4

yeast produces ethanol but muscles produce lactic acid
yeast produces CO2 but muscles do not
both release small amounts of
energy

Question 5

liquid parafin

Answer 5

stops air from getting in

Question 6

Describe how glucose from the small intestine is moved to a muscle cell

Answer 6

glucose is absorbed by diffusion into the bloodstream
then blood delivers glucose to muscles in capillaries