Proteins

Question 1

What makes up proteins?

Answer 1

One or more polypeptide chains which are made from amino acids

Question 2

When is a dipeptide formed?

Answer 2

When two amino acids join together

Question 3

When is a polypeptide formed?

Answer 3

When more than two amino acids join together

Question 4

What bond forms between the amino acids when peptides are formed?

Answer 4

peptide bonds

Question 5

What components make up an amino acid?

Answer 5

A carboxyl group (COOH)
An amino group (NH2)
A variable ‘R’ group

Question 6

How many different amino acids are there?

Answer 6

20

Question 7

What is the only difference between all of the amino acids?

Answer 7

The variable R group

Question 8

Through what reaction are dipeptides and polypeptides formed? What product is released?

Answer 8

condensation

a water molecule

Question 9

What are the 4 levels to the structure of protein?

Answer 9

Primary
Secondary
Tertiary
Quaternary

Question 10

Describe the primary structure of protein.

Answer 10

A sequence of amino acids in a polypeptide chain

Question 11

What bonds are there in a primary structure?

Answer 11

Peptide

Question 12

What is the structure of the secondary stage of protein?

Answer 12

Alpha helix or

Beta pleated sheet

Question 13

What bonds are there in the secondary structure of proteins?

Answer 13

peptide

hydrogen

Question 14

Describe the tertiary structure.

Answer 14

The secondary structure is curled and folded even further

Question 15

What bonds are there in the tertiary structure?

Answer 15

peptide
hydrogen
ionic
disulfide bridges

Question 16

What makes up the quaternary structure?

Answer 16

More than 2 polypeptide chains

Question 17

Describe the test for proteins.

Answer 17

BIURET TEST
1) add a few drops of sodium hydroxide solution to make the sample alkaline
2) Then add copper sulfate solution
Positive result=purple colour
Negative result= blue colour