Proteins

Question 1

What are the functions of proteins?

Answer 1

Enzymes, hormones, oxygen transporters

Question 2

What do proteins form?

Answer 2

Skin, hair, feathers, nails and cartilage

Question 3

What is the monomer of protein?

Answer 3

Amino acids

Question 4

What are the 3 groups in amino acids?

Answer 4

1. Variable R group
2. Amino group
3. Carboxyl group

Question 5

What type of group is an amino group?

Answer 5

Basic group

Question 6

What type of group is a Carboxyl group?

Answer 6

Acidic groupn

Question 7

What is a dipeptide?

Answer 7

A peptide composed of 2 amino acids

Question 8

What is the simplest amino acid?

Answer 8

Glycine

Question 9

What bond links together amino acids to form proteins?

Answer 9

Peptide bond

Question 10

Through what reaction are amino acids bonded?

Answer 10

Condensation reaction

Question 11

What are the 4 levels of protein structure?

Answer 11

Primary structure, secondary structure, tertiary structure, quaternary structure

Question 12

Define primary structure.

Answer 12

Type, number and sequence of amino acids linked by a peptide bond in a polypeptide

Question 13

Define secondary structure.

Answer 13

Folding shape that the polypeptide chain forms as a result of hydrogen bonding

Question 14

What are the 2 secondary structures of proteins?

Answer 14

1. Coil into an alpha helix
2. Fold into a beta pleated sheet

Question 15

What 2 groups are in an alpha helix?

Answer 15

1. Amine group
2. Carboxyl group

Question 16

What is an amine group?

Answer 16

Nitrogen atom having a lone pair

Question 17

What is a carboxyl group?

Answer 17

Carbon atom double bonded to an oxygen atom and singly bonded to a hydroxyl group

Question 18

Define tertiary structure.

Answer 18

Overall specific 3D shape of polypeptide chain.

Question 19

What are the 2 main groups of the tertiary structure?

Answer 19

1. Globular proteins
2. Fibrous proteins

Question 20

Define globular proteins.

Answer 20

Soluble proteins.

Question 21

What are some examples of globular proteins?

Answer 21

Enzymes and haemoglobin

Question 22

Define fibrous proteins.

Answer 22

Insoluble proteins

Question 23

What is an example of fibrous proteins?

Answer 23

Collagen

Question 24

What do fibrous provide?

Answer 24

Structural support

Question 25

What are the bonds in tertiary structure?

Answer 25

Hydrogen, ionic, disulphide

Question 26

Define hydrogen bond.

Answer 26

Form between strongly polar groups such as oxygen and hydrogen

Question 27

How can hydrogen bonding be broken?

Answer 27

High temperature or pH changes

Question 28

Define disulphide bond.

Answer 28

Form between sulphur atoms of 2 cysteine (type of amino acid) molecules

Question 29

How can disulphide bonds be broken?

Answer 29

Reducing agents

Question 30

Define ionic bonds.

Answer 30

Form between ionised amine and carboxylic acid group

Question 31

How can ionic bonds be broken?

Answer 31

pH changes

Question 32

Define hydrophobic bonds.

Answer 32

Occur between non polar side chains

Question 33

Define quaternary structure.

Answer 33

Combination of 2 or more polypeptide chains in tertiary form

Question 34

What are some example of proteins with quaternary structure?

Answer 34

Haemoglobin and collagen

Question 35

How many polypeptide chains does haemoglobin contain?

Answer 35

4 - 2 alpha chains
- 2 beta chains

Question 36

What structure is haemoglobin?

Answer 36

Quaternary

Question 37

Is haemoglobin globular?

Answer 37

Yes

Question 38

What is the prosthetic group of haemoglobin?

Answer 38

Haem group

Question 39

Define prosthetic group

Answer 39

Non protein found within the protein molecule

Question 40

What type of structure is collagen?

Answer 40

Quaternary

Question 41

How many polypeptide chains in collagen?

Answer 41

3

Question 42

Why is glycine every 3 amino acids in collagen?

Answer 42

It is the smallest amino acid so fits tightly