year 12 content pg test wrong questions

Question 1

formation of an enzyme substrate complex increases the rate of reaction.
Explain how. (2)
.

Answer 1

-enzyme provides alternate pathway with lower activation energy
-puts stress on/bends the bonds.

Question 2

lyxose binds to the enzyme.
Suggest a reason for the difference in the results shown in teh graph with and without lyxose. (3)

Answer 2

-lyxose changes tertiary structure of enzyme
-active site of enzyme changes shape
-more enzyme substrate complexes form.

Question 3

suggest how the courtship sequence provides evidence to support the claim taht the two species are separate species. (1)

Answer 3

additional action in sequence.

Question 4

the diagram shows the co transport mechanism for the absorption of amino acids into the cell lining the ileum

the addition of a respiratory inhibitor stops the absorption of amino acids.
use the diagram to explain why (3)

Answer 4

less respiration
-less ATP produced

-no active transport of sodium ions.

Question 5

explain how the organic bases help to stablise the structure of DNA. (2)

Answer 5

-hydrogen bonds between base pairs holds the 2 strands together
-many hydrogen bonds provides strength.

Question 6

Suggest the role of the mRNA base triplets UGA, UAG, and UAA (2)

Answer 6

-stops translation
-results in detachment of polypeptide chain from ribosome.