Proteins: Primary and secondary structure

Question 1

What is the result of proteins having a unique shape?

Answer 1

They have different functions in organisms

Question 2

What is a polypeptide?

Answer 2

A long chain of amino acids linked together

Question 3

What determines the primary structure of the protein?

Answer 3

order of amino acids

Question 4

how many naturally occurring amino acids are there? How many combination does that result in ?

Answer 4

20
Trillions of combinations

Question 5

Are polypeptides always straight?

Answer 5

No, they can curl and fold into 2 main shapes:
- alpha-helices
- Beta pleated sheets

Question 6

What is the meaning of helix?

Answer 6

Coil/Spring shaped

Question 7

What causes the polypeptide shape variations to occur?

Answer 7

The structure of amino acids

Question 8

How does alpha helix structure form?

Answer 8

polypeptide chain coils and the hydrogen bonds between oxygen and hydrogen keep the coil stable

Question 9

How does the beta pleated sheet structure form?

Answer 9

polypeptide chains form a zig zag and fold over themselves

Question 10

Since hydrogen bonds are weak, how do they keep the
secondary structures stable?

Answer 10

A single hydrogen bond is weak, but many hydrogen bonds collectively keep the secondary structure stable

Question 11

Define secondary structure of a protein

Answer 11

It is the curling or folding of a polypeptide chain into alpha-helices or beta pleated sheets due to formation of hydrogen bonds