Introduction To Biological Molecules

Question 1

What makes up an atom ?

Answer 1

Neutrons
Electrons
Protons

Question 2

How are Ionic Bonds formed ?

Answer 2

Formed by the loss/gain of an electron

Question 2

What is an ionic bond ?

Answer 2

The electrostatic force of attraction between positive and negative ions.

Question 3

What is a key feature of ionic bonds ?

Answer 3

They are soluble in water.

Question 4

How are covalent bonds formed ?

Answer 4

Formed due to sharing of electrons

Question 5

What is a covalent bond ?

Answer 5

A covalent bond is the electrostatic force of attraction between 2+ molecules for the shared pair of electrons.

Question 6

Which is stronger covalent bond or ionic bond (in biology)?

Answer 6

Covalent bonds

Question 7

How are the electrons shared in a polar bond ?

Answer 7

They are not shared equally

Question 8

Intermolecular forces

Answer 8

Intermolecular forces are forces that exist between molecules.

Question 9

Intramolecular forces

Answer 9

Intramolecular forces are the forces that hold atoms together within a molecule.

Question 10

What are different types of interactions between R groups ?

Answer 10

Ionic Bonds
Hydrogen Bonds
Hydrophobic interactions
Disulphide bridges
London Dispersion forces

Question 11

What is the general formula of a Sugar ?

Answer 11

(CH2O)n

Question 12

What is the function of sugars ?

Answer 12

They are a source of energy for a cell

Question 13

Name some examples of sugars (3)

Answer 13

Glucose
Fructose
Galactose

Question 14

What are carbohydrates ?

Answer 14

Sugar molecules can be joined together to make a carbohydrate.

Question 15

Features of fatty acids (2)

Answer 15

Can be saturated or unsaturated
Can be both hydrophilic and hydrophobic

Question 16

What can fatty acids be stored as ?

Answer 16

Triacyl-glycerols (for energy reserve)

Question 17

Structure of fatty acids

Answer 17

Hydrophilic head
2 Hydrophobic fatty acid tails

Question 18

What is the hydrophilic head made up of ?

Answer 18

A polar group
A phosphate
A glycerol

Question 19

What are Steroids made up of ?

Answer 19

4 Fused carbon rings
With functional groups attached

Question 20

Name the 5 classes of Biomolecules

Answer 20

Sugar (Carbohydrates)
Fatty Acids
Amino Acids
Steroids
Nucleotides

Question 21

Give 2 examples of steroids

Answer 21

Testosterone
Cholesterol

Question 22

Structure of an amino acid

Answer 22

Amino acids have a CENTRAL carbon, with 4 bonded groups :

• NH2 (Amine group) or NH3+
• COOH (Carboxyl group) or COO-
• H (A hydrogen atom)
• R (A variable R group)

Question 23

How are amino acids joined together ?

Answer 23

Amino acids are joined together via a peptide bond, by a CONDENSATION POLYMERISATION reaction.

Question 24

How are amino acids classified ?

Answer 24

By the different side chains.

Question 25

What are the 4 classes of amino acids ?

Answer 25

Acidic (COO-)
Basic (NH3+)
Polar (slight charge -OH)
Hydrophobic (no charge -CH3 or carbon ring)

Question 26

Uses of amino acids (3)

Answer 26

Sources of energy
Neurotransmitters
Precursors for other molecules

Question 27

What is the structure of a nucleotide ?

Answer 27

A nitrogen ring linked to a 5 carbon sugar.
Sugar can be ribose or deoxyribose.

Question 28

Functions of nucleotides

Answer 28

Short term energy store (ATP & GTP)
Store of electrons
Cofactors for enzymes
Signalling molecules
Building blocks for nucleic acid (DNA/RNA)

Question 29

Cofactor

Answer 29

Non-protein component required for biological activity

Question 30

What can biomolecules be ?

Answer 30

Hybrids

Question 31

Function of glycoproteins

Answer 31

Glycoproteins often identify and bind to receptors on a host cell. Critical for establishing an infection.

Question 32

What are viruses coated in ?

Answer 32

Glycoproteins