Biology Protein exam questions

Question 1

A competitive Inhibitor decreases the rate of an enzyme controlled reaction. Explain how?

Answer 1

The competitive inhibitor has a similar shape to enzymes active site. IT binds to the active site which prevents enzyme substrate complexes forming

Question 2

When bred bec omsde stale the structure of starch is changed. scientist have suggested retrograded starch is a competitive inhibitor of amylase in the small intestine. Suggest hiw stale bread could help you to reduce weight gain.

Answer 2

amylase wont hydrolyse starch into maltose meaning that no glucose is formed so less glucose absorbed in the body

Question 3

describe how the structure of a protein depends on the amino acids it contains.

Answer 3

-strcture of protein depends on the position of the amino aicds on their chain.
-primary = order of AA
-secondary - h binds form between carboxyl and amine group to from aplha helix or b pleated sheets
- tertiary - h,ionic and disulphide bonds cause further doling between eptide binds
- quaternary - more than 2 polypeptide joined tg

Question 4

describe how amino acids join to form a polypeptide so there is always NH2 at one ebd and COOH at the other

Answer 4

always one free carboxyl group and amine group which joins together to form a peptide bond.

Question 5

Answer 5

Triglyceride has gone down because of the action of lipase
Triglycerides decreased because of the hydrolysis
Triglycerides decrease because of digestion of ester bonds

Question 6

After collecting samples the scientist immediately heated them to 70 degrees for 10 minutes

Answer 6

To denature the enzymes to no further hydrolysis can occur

Question 7

Describe the role of micelles in the absorption of fats into the cells lining the ileum

Answer 7

1. Micelle include bile salts and fatty acids
   2 this makers the fatty acids more soluble in Water
2. Bring fatty acids to lining of ileum
3. Maintain a higher concentration of fatty acids to lining
4. Fatty acids absorbed by digestion