Section 1 - Proteins

Question 1

What are proteins composed of?

Answer 1

Long chains of amino acids

Question 2

How many different amino acids are there that are used in proteins?

Answer 2

20

Question 3

What elements do amino acids contain?

Answer 3

They all contain carbon, hydrogen, oxygen and nitrogen, and some contain sulfur.

Question 4

What are the amino acids in a protein chain attached to each other by?

Answer 4

Strong peptide bonds

Question 5

How is the order of amino acids in a protein significant?

Answer 5

The order of the amino acids in a protein determines its structure and it’s the structure of a protein that determines how it works.

Question 6

Primary structure

Answer 6

The order in which the amino acids are arranged in a protein chain is called the primary structure.

Question 7

Secondary structure

Answer 7

Some chains coil up or fold into pleats that are held together by weak forces of chemical attraction called hydrogen bonds. The coils and pleats are the secondary structure of a protein.

Question 8

Tertiary structure

Answer 8

Some proteins (especially enzymes) have a tertiary structure. The coiled chain of amino acids is folded into a ball that’s held together by a mixture of weak chemical bonds (e.g. hydrogen bonds) and stronger bonds (e.g. disulfide bonds).

Question 9

In a proteins tertiary structure, what is the ball of coiled chains of amino acids held together by?

Answer 9

A mixture of weak chemical bonds (e.g. hydrogen bonds) and stronger bonds (e.g. disulfide bonds).

Question 10

What is a globular protein?

Answer 10

A protein with a roughly spherical shape. Enzymes are classed as globular proteins.