1. Biological Molecules - Proteins

Question 1

What are 2 examples of amino acids?

Answer 1

L-Histidine and L-Isoleucine

Question 2

Describe the structure of an amino acid?

Answer 2

-Carboxyl group COOH
-Amino group NH2
-Different R groups

Question 3

How are peptide bonds formed?

Answer 3

Due to a condensation reaction, where the carboxyl group of one amino acid joins to the amino group of another amino acid.

Question 4

What chemical property does a polar R group have?

Answer 4

Hydrophilic

Question 5

What chemical property does a non-polar R group have?

Answer 5

Hydrophobic

Question 6

What chemical property does a positively charged R group have?

Answer 6

Hydrophilic

Question 7

What chemical property does a negatively charged R group have?

Answer 7

Hydrophilic

Question 8

What are the typical secondary structures?

Answer 8

α-helices and β-pleated sheets

Question 9

How do secondary structures form?

Answer 9

As a result of hydrogen bonding between carboxyl and amino residues

Question 10

How do tertiary structures fold into their complex, specific shapes?

Answer 10

Due to intermolecular forces between different types of bonds in R groups

Question 11

What are the 4 different kinds of bonds which create intermolecular forces to hold together tertiary structures?

Answer 11

-Hydrogen bonds
-Ionic forces
-Disulfide bridges
-London forces

Question 12

What do hydrogen bonds form between?

Answer 12

Polar R groups AS WELL AS between the carbonyl oxygen of one amino acid and the amide hydrogen of another in the secondary structure (backbone atoms)

Question 13

What do ionic forces form between?

Answer 13

Positive and negative R groups

Question 14

What are disulfide bridges?

Answer 14

Covalent bonds between cysteine R groups

Question 15

What do London forces form between?

Answer 15

Non-polar R groups

Question 16

What are the two groups of quaternary structures?

Answer 16

Globular and fibrous.

Question 17

Give 3 broad examples of globular structured proteins:

Answer 17

-Enzymes
-Signalling molecules
-Transport molecules

Question 18

Give one broad example of a fibrous structured protein:

Answer 18

Structural molecules

Question 19

Give one specific example of a globular protein:

Answer 19

Haemoglobin

Question 20

Give one specific example of a fibrous protein:

Answer 20

Collagen

Question 21

What structure does haemoglobin have?

Answer 21

A quaternary structure

Question 22

What structure does collagen have?

Answer 22

Quaternary structure

Question 23

How many polypeptide chains does haemoglobin have? What do these consist of?

Answer 23

-4 polypeptide chains
-2 α-subunits
-2 β-subunits

Question 24

How many polypeptide chains does collagen have?

Answer 24

3 polypeptide chains

Question 25

What additional group do quaternary structures contain?

Answer 25

Non-amino acid derived groups known as prosthetic groups.

Question 26

How many prosthetic groups does haemoglobin have?

Answer 26

4 heme prosthetic groups

Question 27

Give 4 examples of what prosthetic groups can be formed from:

Answer 27

-Metal ions
-Methyl groups
-Phosphate groups
-Vitamins