Metabolism

Question 1

In Glycolysis: What are the Carriers.

Answer 1

ATP, NADH, Acetyl CoA

Question 2

What is the NET ATP from Glycolysis?

Answer 2

2

Question 3

What is the NET ATP from TCA?

Answer 3

2

Question 4

What is the NET ATP from ETC?

Answer 4

28

Question 5

Draw the Process of Pyruvate in Anaerobic Conditions

Question 6

What Happens when theres too much Lactate?

Answer 6

body pH drops, too acidic

Question 7

What other Sugars other than Glucose can be used?

Answer 7

galactose and fructose from adipose tissues or liver

Question 8

Describe Lactose Intolerance.

Answer 8

• lactose is too big to pass through digestive tract lining
• must be broken into galactose and glucose by lactase
• if lactase is underproduced
• lactose remains in GI tract
• becomes fermented by bacteria

Question 9

Describe Symptoms of Lactose Intolerance

Answer 9

farting, diarrhoea, cramps, bloating, nausea

Question 10

Describe Galactosemia

Answer 10

inherited autosomal recessive disorder

• deficiency of galactose-1-phosphate uridyl transferase
• in the eye..
• aldose reduces galactose into galacitol

Question 11

What are the Symptoms of Galactosemia

Answer 11

cataracts in the eye, enlargement of liver, CNS failure

Question 12

HOW does Fluoride kill cariogenic bacteria?

Answer 12

inhibits Enolase

• enzyme needed to convert 2-phosphopglycerate into PEP
• think glycolysis

Question 13

State and Describe 4 Mechanisms in which Metabolism can be Regulated.

Answer 13

1. Allosteric Regulation
   - enzyme activity can be inhibited by binding an effector molecule at a site other than the enzyme’s active site
2. Association with Regulatory Protein
3. Covalent Modification
   - phosphorylation
4. Sequestration
   - alters accessibility of reactions, products and substrates

Question 14

What are the 4 Main Enzymes in Glycolysis?

Answer 14

Hexokinase
Phosphofructokinase
Pyruvate Kinase
Pyruvate Dehydrogenase

Question 15

How is Hexokinase Regulated?

Answer 15

Allosteric Regulation

• inhibit Glucose into G-6-P

Question 16

2 Ways in Which the Activity of Phosphofructokinase is Reduced?

Answer 16

1. Allosteric Regulation by ATP
   - ATP is overproduced
   - binds to allosteric site
   - lowers the PFK affinity
2. Sensitivity to pH
   - high acidity reduces activity
   - prevents formation of lactic acid

Question 17

How Can Phosphofructokinase be Activated

Answer 17

by Fructose-2,6-Bisphosphate

• binds to allosteric site
• increase enzyme affinity for F-6-P
• reduces affinity for ATP

Question 18

How is the Activity of Pyruvate Kinase Regulated?

Answer 18

allosteric regulation and covalent modification

Question 19

How is Pyruvate Kinase Activated?

Answer 19

Fructose-1,6-Bisphosphate

Question 20

How is Pyruvate Dehydrogenase Regulated?

Answer 20

allosteric regulation and covalent modification

has 2 limiting sited
E2 Transacetylase - limited by Acetyl CoA
E3 Dihydrolipolydehydrogenase - limited by NADH

Question 21

What are the Main Enzymes in TCA?

Answer 21

citrate synthase
isocitrate dehydrogenase
a-ketoglutarate dehydrogenase

Question 22

Draw out Glycolysis

Question 23

Where does Glycolysis Occur?

Answer 23

in the cystol of the cell

Question 24

What are the 5 Main Stages in Glycolysis and where do they occur, using enzymes?

Answer 24

1) Irreversible Phosphorylation
- hexokinase

2) Isomerisation - Aldose to Ketone
- phosphoglucose isomerase

3) Irreversible Phosphorylation
- phosphofructose kinase

4) Cleavage
- Aldose

5) Isomerisation
- Triose Phosphate Isomerase
- DHAP into GAP

Question 25

Draw out Link Reaction

Question 26

Where does Link Reaction Occur?

Answer 26

matrix of the mitochondria

Question 27

Draw out TCA Cycle

Question 28

What are the 9 Steps of TCA Cycle?

Answer 28

1. Condensation 2. Condensation 3. Hydration 4. Oxidative Decarboxylation 5. Oxidation Decarboxylation 6. Substrate Level Phosphorylation 7. Dehydrogenation 8. Hydration 9. Dehydrogenation

Question 29

What is the only sugar the brain will use?

Answer 29

glucose

Question 30

Draw Glycolysis.

Question 31

Draw Glycolysis in the liver and in the muscles.

Question 32

What 2 Enzymes are needed at a branch point?

Answer 32

Transferase Enzyme - transfers 3 glucose units from one end to another Amylo-a-1,6-glucosidase - hydrolyses the single glucose unit left behind

Question 33

How does Adrenaline and Glucagon work? Draw it out. (cAMP)

Question 34

Draw Out Glycogenesis

Question 35

What is Anderson's Disease?

Answer 35

deficiency of branching enzyme liver failure and death in first year of life

Question 36

Insulin activates PK, what is this?

Answer 36

protein kinase

Question 37

how does protein kinase work, draw it out.

Question 38

How does Gluconeogenesis work?

Answer 38

the opposite of glycolysis, bypassing the irreversible steps

Question 39

Draw out the Steps of Gluconeogenesis

Question 40

Where does Gluconeogenesis Occur?

Answer 40

in the liver

Question 41

What are the precursors for Gluconeogenesis?

Answer 41

lactate glycerol amino acids

Question 42

Draw out the roles of lactate and glycerol.

Answer 42

lactate into pyruvate by lactate dehydrogenase glycerol + ATP into glycerol phosphate + ADP + H+ into DHAP by glycerol kinase and then glycerol phosphate dehydrogenase

Question 43

State Steps of ETC.

Answer 43

1. NADH-Q reductase complex 2. succinate dehydrogenase 3. cytochrome c reductase complex 4. cytochrome c oxidase complex

Question 44

What is the Proton Motive Force?

Answer 44

change in ph + change in charge gradient

Question 45

Describe Structure of ATP Synthase

Answer 45

two functional domains = F0 and F1

Question 46

Describe F0 from ATP Synthase

Answer 46

- imbedded in the inner mitochondrial mem - has a proton pore - has multiple subunits C subunits rotate - has aspartic acid in the middle - when in contact with membrane = neutral charger - when in contact with a unit = negative charge B subunit stuck on the outside - 2 half channels - hydrogen diffuses in Galway

Question 47

How does F0 work?

Answer 47

- aspartic acid in contact with a complex = negative charge - c subunits cant move - due to chemical gradient, protons move in = positive charge - c subunit rotates clockwise - repeats

Question 48

What is the F1 Complex, Explain Subunits?

Answer 48

contains the catalytic activity of the synthase 5 Subunits 3 a, 3 b, 1g - only gamma rotates and determines the state - open state = ATP release - tense state = ATP produced

Question 49

Describe Muscle Shuttle

Answer 49

- e- from NADH transport into mitochondria via glycerol-3-phosphate shuttle

Question 50

Draw Muscle Shuttle.

Question 51

How does ATP synthase travel in the Heart and Liver

Answer 51

Malate-Aspartate Shuttle

Question 52

Draw Malate-Aspartate Shuttle.

Answer 52

NADH donates e- to oxaloacetate to form malate - malate dehydrogenase malate goes across the mitochondrial membrane malate back into oxaloacetate - mitochondria malate glutamine + oxaloacetate = aspartate - aminotransferase

Question 53

What is the Purpose of the Pentose Pathway?

Answer 53

to oxidise glucose to create NADPH

Question 54

Draw out Pentose Pathway

Question 55

What is a Toxic Bi-Product of Oxidative Phosphorylation, what percents is it found in?

Answer 55

ROS 1%

Question 56

How do you get rid of ROS?

Answer 56

NADPH - reduced glutathione::: - hydrogen peroxide into water using *glutathione peroxidase* - oxidised glutathione::: - uses *glutathione reductase* and NADPH to become reduced = repeat process

Question 57

What Happens if you have a Deficiency in G-6-P Dehydrogenase?

Answer 57

no ability to produce NADPH = no detoxification - problem when under oxidative stress BUT INHIBITS MALARIA PARASITE