Cell Metabolism 1 original

Question 1

What is involved in an oxidation - reduction reaction?

Answer 1

Electron transfer

Question 2

What is involved in ligation requiring ATP cleavage?

Answer 2

Formation of covalent bonds eg. Carbon-carbon

Question 3

What is involved in isomerisation?

Answer 3

Rearrangement of atoms to form isomers

Question 4

What is involved in group transfer?

Answer 4

Transfer of one functional group to another

Question 5

What is involved in a hydrolytic reaction?

Answer 5

Cleavage of bonds by the addition of water

Question 6

What is involved in a reaction where functional groups are added or removed?

Answer 6

Addition of functional groups to double bonds or their removal to form double bonds

Question 7

Describe the enzyme required for the phosphorylation / functional group transfer from ATP to glucose and the resulting molecule.

Answer 7

Hexokinase and glucose 6-phosphate

Question 8

Describe the enzyme and type of reaction in glycolysis involving glucose-6-phosphate

Answer 8

Phosphoglucose (PG) isomerase, isomerization

Question 9

Name the product produced in the isomerization of glucose-6-phosphate and describe why this step is useful

Answer 9

Fructose 6 phosphate; it is useful because the pentose sugar can later be split into two equal parts

Question 10

Name the enzyme needed to form fructose-1,6-biphosphate and any other molecules involved

Answer 10

phosphofructokinase (PFK) Fructose-6-phosphate, ATP

Question 11

Name the enzyme used to cleave fructose-1,6-biphosphate

Answer 11

Aldolase

Question 12

Name the two molecules produced when fructose-1,6-biphosphate is cleaved and the type of reaction

Answer 12

Dihydroxyacetone phosphate and glyceraldhehyde 3-phosphate, hydrolytic cleavage

Question 13

What type of reaction converts dihydroxyacetone into glyceraldehyde 3-phosphate and which enzyme is used?

Answer 13

Isomerization and triose phosphate isomerase

Question 14

Which step in hydrolysis involves the investment of 2 molecules of ATP?

Answer 14

Step 1

Question 15

Which step of glycolysis involves the splitting of a high energy compound?

Answer 15

Step 2

Question 16

What is the net gain of ATP in glycolysis?

Answer 16

2 ATP

Question 17

How many ATP are formed during stage step 2 of glycolysis?

Answer 17

4

Question 18

What type of reaction changes glyceraldehyde-3-phosphate into 1,3-biphosphoglycerate, which enzyme is used and what other molecules are involved?

Answer 18

Dehydrogenation and group transfer/phosphorylation, glyceraldehyde-3-phosphate dehydrogenase, NAD+ —> reduced NADH, inorganic phosphate group is added

Question 19

Which enzyme and small molecule are used to transfer a group from 1,3-biphosphoglycerate and which molecules are produced?

Answer 19

Phosphoglycerate kinase and 2 ADP, forming 2 3-phosphoglycerate and 2 ATP

Question 20

Which enzyme forms 2-phosphoglycerate, which molecule does it act on and what type of reaction is it?

Answer 20

Phosphoglycerate mutase, 3-phosphoglycerate and isomerization

Question 21

Which enzyme is used to remove a group from 2-phosphoglycerate and which molecule is formed? Which group is removed?

Answer 21

Enolase, phosphoenolpyruvate, H2O

Question 22

Which enzyme is used to form pyruvate and from which molecule is it formed? Which other small molecule is formed/made in the process?

Answer 22

Pyruvate kinase, phosphoenolpyruvate, ATP

Question 23

Name the 3 fates of pyruvate

Answer 23

Lactate, ethanol and acetyl CoA

Question 24

Name the enzyme that converts pyruvate to lactate and which other molecules are converted in the reaction.

Answer 24

Lactate dehydrogenase and NADH+H+ —> NAD+ (2H add onto pyruvate). This reaction is reversible (lactate can be oxidised to form pyruvate)

Question 25

Which enzyme is used to convert pyruvate to acetaldehyde? Which molecule is released during this reaction?

Answer 25

Pyruvate decarboxylase, carbon dioxide

Question 26

Which enzyme converts acetaldehyde to ethanol?

Answer 26

Alcohol dehydrogenase

Question 27

Which molecule is oxidised when acetaldehyde is converted to ethanol?

Answer 27

NADH + H+ —> NAD+ (acetaldehyde is reduced)

Question 28

In aerobic respiration, what is pyruvate converted into? Which enzymes are required?

Answer 28

Acetyl CoA, pyruvate dehydrogenase complex

Question 29

When pyruvate is converted to acetyl CoA, which other molecules are involved? Describe what happens

Answer 29

HS-CoA transfers to pyruvate, losing a hydrogen which goes on to NAD+, forming the reduced NADH. Carbon dioxide is released as a bi-product

Question 30

Which enzyme converts Creatine phosphate to Creatine and which other molecule is made in the process?

Answer 30

Creatine kinase and ATP

Question 31

What is the function of Creatine/Creatine phosphate

Answer 31

Buffer needed for phosphate to form ATP during exercise

Question 32

What is the name of the high energy bond in acetyl CoA? What is special about it?

Answer 32

Thioester - it is readily hydrolysed and therefore acetyl CoA is ready to donate acetate (2C) to other molecules

Question 33

A deficiency of which vitamin causes Beri beri?

Answer 33

Thiamine

Question 34

What are the effects of Beri Beri?

Answer 34

Damage to the peripheral nervous system, weakness of the musculature and decreased cardiac output

Question 35

Why is thiamine important in the pyruvate dehydrogenase complex?

Answer 35

It acts as a cofactor, losing a proton resulting in a carbanion which readily attack’s pyruvate