functions of proteins

Question 1

what is the structure of an enzyme?

Answer 1

they’re a spherical shape due to the tight folding of the polypeptide chains.

Question 2

what are functions of enzymes?

Answer 2

They’re soluble. They have different functions, some digest large molecules into smaller ones or synthesise (make) larger molecules

Question 3

what is the structure of structural proteins?

Answer 3

consist of long polypeptide chains that sit parallel with crosslinks between them

Question 4

what are functions of structural proteins?

Answer 4

supportive tissue in animals like keratin (hair and nails) or collagen (connective tissue)

Question 5

what is the structure of antibodies?

Answer 5

made up of 2 short polypeptide chains and 2 heavy (long) chains with variable regions (different amino acid sequences)

Question 6

what is the function of antibodies?

Answer 6

they’re part of the immune system and bind with specific antigens to bring out an immune response

Question 7

what is the structure and function of haemoglobin?

Answer 7

4 polypeptide chains in a compact shape. It is soluble and carries oxygen by unloading and loading

Question 8

how do you test for proteins?

Answer 8

biuret test

Question 9

describe the biuret test?

Answer 9

1. add 2cm3 of distilled water to test tube containing sample
2. add equal volume of dilute sodium hydroxide solution
3. add a few drops of very dilute copper sulphate solution
4. gently mix
5. if proteins are present, solution turns from blue to lilac/purple

Question 10

what 2 things make up the buret solution

Answer 10

sodium hydroxide
copper sulfate