Biological Molecules

Question 1

What is the difference between an alpha glucose molecule and a beta glucose molecule ?

Answer 1

Hydroxyl (OH) on the bottom right of alpha
Hydroxyl group is on the top right in a beta glucose molecule

Question 2

How does cellulose differ from starch and glycogen ?

Answer 2

Made from Beta glucose
Others are made from alpha glucose

Question 3

What bond is formed in lipid molecules and how is it formed ?

Answer 3

Ester bonds
Formed via condensation reaction
Between glycerol molecule and fatty acid

Question 4

What does the ‘ R ‘ group in a fatty acid determine ?

Answer 4

Whether or not the molecule will be saturated (single C-C )
Or unsaturated (C=C)

Question 5

What differentiates amino acids ?

Answer 5

Their R groups

Question 6

How is a dipeptide formed ?

Answer 6

Between two amino acids

Question 7

Describe the ‘ Induced-fit model ‘

Answer 7

Active site not initially complementary to substrate
Substrate collides, binds - induces change in shape of active site
Enzyme-Substrate complexes form
Substrate bonds are stressed and broken
Lowers activation energy

Question 8

Describe the structure of DNA

Answer 8

Polymer of nucleotides
Double helix
Hydrogen bonds
Complementary Base Pairing

Question 9

Describe the process of ‘Semi - Conservative replication ‘

Answer 9

Dna helicase breaks hydrogen bonds between complemntary bases
Split into two chains
Both acting as template strands (DNA)
Free Dna nucleotides join via complementary base pairing
Adenine - Thymine , Cytosine - Guanine
Adjacent nucleotides joined via phosphodiester bonds
Catalysed by DNA Polymerase
Forms newly synthesised strand and original DNA strand

Question 10

What sort of molecule is ATP ?

Answer 10

A nucleotide

Question 11

Describe the structure of ATP

Answer 11

Nucleotide
Pentose (Ribose) sugar
Nitrogenous base (Adenine)
3 phosphate groups

Question 12

What are the products of hydrolysis of ATP ?

Answer 12

ADP
Pi ; inorganic phosphate group

Question 13

How can the ‘ inorganic phosphate group ‘ be utilised ?

Answer 13

Phosphorylation of compounds
Making them more reactive

Question 14

How is ATP resynthesised ?

Answer 14

ADP + Pi
Catalysed by ATP synthase

Question 15

When is ATP resynthesised ?

Answer 15

Photosynthesis
Respiration

Question 16

How is water useful in metabolic processes ?

Answer 16

Acts as a metabolite
E . g. Condensation, hydrolysis

Question 17

How does water allow for metabolic processes to occur ?

Answer 17

Acts as a solvent

Question 18

How does Water act as a buffer ?

Answer 18

Very high specific heat capacity (Heat required to raise 1kg of substance by 1 degree)
Buffers solutions

Question 19

What property of water allows it to travel as a continuous column ?

Answer 19

High cohesion
Between water molecules
Due to hydrogen bonding
Allowing for travel as a continuous column and provides surface tension

Question 20

What property of iron allows it to carry out its job in Haemoglobin ?

Answer 20

Charged/Polar molecule
Able to bind to oxygen

Question 21

How is ATP formed from its component molecules ?

Answer 21

Three phosphates
Ribose sugar
Adenine
Joined via condensation reactions
Catalysed by ATP synthase

Question 22

Where is the ‘ OH ‘ located on an alpha glucose molecule

Answer 22

At the top

Question 23

What is the byproduct of the formation of a trisaccharide ?

Answer 23

2H20

Question 24

Describe the role of hydrogen ions

Answer 24

Lowers Ph of solutions (acidic)
Impacting enzyme function
Impacts haemoglobin function

Question 25

Describe the role of iron ions

Answer 25

Polar
Bind to oxygen in haemoglobin

Question 26

Describe the role of sodium ions

Answer 26

Involved in co-transport of glucose and amino acids

Question 27

Describe the role of phosphate ions

Answer 27

Dna component
Phosphorylation of other compounds