Cell Metabolism

Question 1

Three stages of Cellular Metabolism

Answer 1

Glycolysis TCA Cycle Oxidative phosphorylation

Question 2

Glycolysis

Answer 2

Oxidation of glucose within the cytosol of individual cells, generating ATP and NADH

Question 3

TCA Cycle

Answer 3

Oxidation of small molecules within the mitochondria generating ATP, NADH, FADH2 and waste products

Question 4

Oxidative Phosphorylation

Answer 4

generation of ATP by reduction of oxygen to water

Question 5

How many ATP molecules produced

Answer 5

36-38 ATP

Question 6

6 reactions of metabolism

Answer 6

1. Oxidation-reducation 2. Ligation requiring ATP cleavage (formation of covalent bonds) 3. Isomerization - 4. Group transfer - transfer of functional group from one moelcule 5. Hydrolytic - Cleavage of bonds by addition of water 6. Addition or removal of functional groups - Form or remove double bonds

Question 7

How many reactions make up glycolysis pathway

Answer 7

10 (formation of a high energy compound and splitting of a high energy compounds)

Question 8

Step 1 of Glycolysis

Answer 8

Irreversible

Negative charge traps glucose inside the cell

“kinase” - carries out phosphorylation

Question 9

Step 2 of Glycolysis

Answer 9

Isomerisation

Able to split into equal halves later

Question 10

Step 3 of Glycolysis

Answer 10

IMPORTANT REACTION

Regulation of phosphofructokinase

Question 11

Step 4 of Glycolysis

Answer 11

Two high energy compounds have been generated

Question 12

Step 5 of Glycolysis

Answer 12

Only glycolytic enzymopathy that is fatal

Important for endocrinologist

Question 13

Step 6 of Glycolysis

Answer 13

NADH is generated which can produce more ATP in oxidative phosphorylation

Question 14

Step 7 of Glycolysis

Answer 14

Transfer of phosphate groups

Question 15

Step 8 of Glycolysis

Answer 15

Phosphate goes from 3 position to 2 position

Question 16

Step 9 of Glycolysis

Answer 16

Dehydration reaction

Question 17

Step 10 of Glycolysis

Answer 17

Question 18

Alcoholic Fermentation

Answer 18

Characteristic of yeasts

Carboxylase = removes carboyl groups

Question 19

Generation of Lactate

Answer 19

Anaerobic respiration

Oxygen is a limiting factor

Question 20

Why NAD+ regeneration is essential

Answer 20

It is required for glycolysis for the dehydrogenation of glyceraldehyde 3-phosphate

Question 21

What is creatine phosphate used as

Answer 21

Buffer for ATP

Thermodynamically favourable

Question 22

Acetyl CoA generation

Answer 22

Occurs in the mitochondria

Question 23

What is Acetyl CoA

Answer 23

Thioester bond is high-energy, can be hydolysed to give off 2C

Question 24

What is Beri Beri?

Answer 24

Poor Pyruvate Dehydrogenase Complex

Cofactor is Thiamine which donates a proton and attacks pyruvate

Question 25

How many molecules are produced/lost in TCA Cycle?

Answer 25

1 GTP OR ATP 3 NADH 1 NADH 2 CO2 In the mitochondria matrix space Enzymes are soluble proteins Because NAD+ needs to be reoxidised under oyxgen, only aerobic respiration

Question 26

What are ketogenic amino acids

Answer 26

Gives rise to ketone bodies

Question 27

What are glucogenic amino acids?

Answer 27

Give rise to glucose

Question 28

Degration to pyruvate

Answer 28

Alanine Cysteine Glycine Serine Threonine Tryptophan

Question 29

Degradation to oxeloacetate

Answer 29

Asparagine Aspartate

Question 30

Degradation to Fumarate

Answer 30

Aspartate Phenylalanine Tyrosine

Question 31

Degradation to succinyl CoA

Answer 31

Isoleucine Methionine Threoine Valine

Question 32

Degradation to a-Keto-Glutarate

Answer 32

Arginine Glutamate Glutamine Histidine Proline

Question 33

Degradation to Acetyl CoA

Answer 33

Isoleucine Leucine Tryptophan

Question 34

Acetoacetyl CoA

Answer 34

Leucine Lysine Phenylalanine Tryptophan Tyrosine

Question 35

What are transamination reactions?

Answer 35

Group transfer of amino acid to a keto acid

Question 36

How is glutamate reconverted to a-ketoglutarate

Answer 36

Glutamate dehydrogenase is used which generates NH4+

Question 37

NADH transportation from skeletal muscle and brain

Answer 37

Glycerol phosphate shuttle

Question 38

NADH transportation of the liver, kidney and heart

Answer 38

Malate-aspartate shuttle

Question 39

What are the steps of the glycerol phsophate shuttle

Answer 39

1. Cytosolic glycerol 3 phosphate dehydrogenase transfers electrons from NADHA to glycerol 3 phosphate 2. Membrane bound mitochondrial glycerol 3-phosphate dehydrogenase transfers electrons to FAD which get passed to co-enzymes Q

Question 40

Malate aspartate shuttle

Answer 40

AT - aspartate transaminase MDH - malate dehydrogenase

Question 41

Glycolysis and Krebs cycle

Answer 41

Black arrow denotes single enzyme catalysed reaction Red arrow represent multi-step pathways

Question 42

TCA cycle goes wrong

Answer 42

Decrease TCA activity Preferrentially undergo glycolysis which produces lactate in ample oxygen

Question 43

Subtrates of kinases

Answer 43

Serine Threonine Tyrosine Contain a hydroxyl group which can be phosphorylated

Question 44

What is substrate-level phosphorylation

Answer 44

Transfer of a high-energy phosphate group to ADP

Question 45

Why can Lactate dehydrogenase be used as a diagnostic tool

Answer 45

Cells release LDH when they die Diagnose disorders including stroke and myocardial infarction

Question 46

What is expressed in glucose metabolism of cancer tumours

Answer 46

GLUT1 Increased glucose transporters