Second Half F24 II: Lecture Slides 80 - 99

Question 1

What will the complete oxidation of glucose produce?

Answer 1

H2O and CO2

Question 2

What are the three stages of the complete oxidation of glucose?

Answer 2

1.) Glycolysis and Pyruvate Dehydrogenase

2.) Citric Acid Cycle

3.) ETC

Question 3

What is the polarity of Glucose?

Answer 3

Glucose is hydrophilic

Question 4

Why can a glucose molecule not diffuse across a membrane?

Answer 4

Due to its hydrophilic properties

Question 5

What molecules catalyze glucose import?

Answer 5

Transporter proteins called GLUTs, residing in the cell membrane

Question 6

What is the many actions of the hormone insulin?

Answer 6

To stimulate GLUT mediated glucose uptake in skeletal muscles and adipose tissue.

Question 7

What is the GLUT-4 transporter?

Answer 7

Specific transporter for insulin and only functioning in the presence of insulin

Question 8

What happens in diabetes?

Answer 8

Blood Glucose is not taken up into the cells adequately.

Question 9

What is the fasting [blood glucose] in the body?

Answer 9

Approximately 5mM

Question 10

What cell types depend solely on glycolysis?

Answer 10

• Red Blood Cells
• Renal Medulla
• Brain
• Sperm

Question 11

What is glycolysis the only pathway known to be able to do?

Answer 11

Provide energy under anaerobic conditions (anaerobic micro-organism are completely depends in glycolysis for energy)

Question 12

Where does glycolysis take place?

Answer 12

In the cytosol

Question 13

What happens in the first 5 reactions of glycolysis?

Answer 13

Using an ATP molecule to activate glucose by phosphorylating it

Question 14

What happens in the last 5 reactions?

Answer 14

Seeing the net generation of ATP

Question 15

What is ATP used as in Step 1: Phosphorylation of Glucose?

Answer 15

ATP is used as cofactor that acts as a carrier/donor of phosphate groups to phosphorylate many types of molecules.

Question 16

What happens in Step 1 of Glycolysis?

Answer 16

ATP is used to turn glucose into glucose-6-phosphate

Question 17

What enzyme helps ATP in this phosphorylation?

Answer 17

Hexokinase

Question 18

What is a Isozyme?

Answer 18

Two or more enzymes that catalyze the same reaction but are encoded by different genes

Question 19

How many isozymes of Hexokinase?

Answer 19

4

Question 20

How does hexokinase 4 differ?

Answer 20

In its kinetic and regulatory properties

Question 21

What happens in step two of glycolysis?

Answer 21

Phosphohexose Isomeration occurs

Question 22

What is a Phosphoisomerisation?

Answer 22

Turning Glucose-6-Phsophate into Frutcose-6-Phosphate

Question 23

What enzyme catalyzes this phosphoisomerisation?

Answer 23

Phosphohexose Isomerase

Question 24

What is the third step of glycolysis?

Answer 24

The second phosphorylation

Question 25

What happens in the second phosphorylation?

Answer 25

Fructose 6-phosphate turns into Fructose 1,6-bsiphosphate

Question 26

What is the enzyme that catalyzes this reaction?

Answer 26

phosphofructokinase-1

Question 27

What is a Bisphosphate?

Answer 27

Has the phosphate in two different positions

Question 28

What is a diphosphate?

Answer 28

The phosphates are connected to each other

Question 29

What is the Fourth Step of Glycolysis?

Answer 29

The Fructose 1,6 bisphosphate splits into two three carbon units

Question 30

What are the two three carbon units?

Answer 30

Dihydrooxyacetone Phosphate and Glyceraldehyde 3 phosphate

Question 31

What is the enzyme that catalyzes this reaction?

Answer 31

Aldolase

Question 32

What happens in the fifth step of Glycolysis?

Answer 32

Interconversions of the triode phosphates (three carbon units)

Question 33

What does the Interconversion of the Triose phosphates do?

Answer 33

Dihydrooxyacetone Phosphate is immediately isomerized into Glyceraldehyde 3-Phosphate

Question 34

What enzyme carries out the reaction of the Interconversion of the Triose phosphates?

Answer 34

Triose Phosphate Isomerase

Question 35

Where does glycolysis continue from?

Answer 35

G3P only

Question 36

From this point onwards, what must happen?

Answer 36

Two triose molecules must be catabolized for each molecule of glucose with which we started

Question 37

What is step 5 of glycolysis?

Answer 37

Glyceraldehyde 3-Phosphate Dehydrogenase Reaction

Question 38

What happens in the dehydrogenase of G3P?

Answer 38

G3P combines with an inorganic phosphate to produce 1,3-biphosphoglycerate

Question 39

What is the enzyme that carries out this reaction?

Answer 39

Glyceraldehyde-3-phosphate dehydrogenase

Question 40

What is the cofactor that carries out this reaction?

Answer 40

The reduced cofactor of NAD to NADH

Question 41

Why is this step the key to glycolysis?

Answer 41

As the 1,3-biphosphoglycerate is a high energy molecule

Question 42

What must happen to the NADH?

Answer 42

It must be reoxidized to carry out glycolysis as an ongoing process

Question 43

What is the sixth step of glycolysis?

Answer 43

Phosphoryl transfer from 1,3-BPG to ADP - The first substrate level phosphorylation

Question 44

What does 1,3BPG turn into?

Answer 44

3-Phosphoglycerate

Question 45

What reaction occurs for this process?

Answer 45

The conversion of ADP To ATP and the enzyme phosphoglycerate kinase

Question 46

What is the free energy of the anhydride bond that was broken recovered in?

Answer 46

The form of ATP

Question 47

What is the overall stoichiometry of this reaction?

Answer 47

Two moles of 1,3-BPG per mole of glucose - so this reaction generates two ATP per glucose

Question 48

What is the 8th step of glycolysis?

Answer 48

Conversion of 3-phsophoglycerate to 2-phosphoglycerate with the use of the enzyme phosphoglycerate mutaste

Question 49

What is a mutate?

Answer 49

A sub class of isomerase: mutates catalyze reactions in which a functional group is shunted between different positions in a molecule

Question 50

What is the 9th step of glycolysis?

Answer 50

Dehydration of 2-phosphoglycerate

Question 51

What does 2-phosphoglycerate turn into?

Answer 51

Phosphoenolpyruvate with the removal of water

Question 52

What enzyme does this?

Answer 52

Enolase

Question 53

What is the 10th step of glycolysis?

Answer 53

Transfer of the phosphorylation group from the phosphoenolpyruvate to ADP: The Second Level Substrate Level Phosphorylation

Question 54

What does Phosphoenolpyruvate turn into?

Answer 54

Pyruvate (enrol form) with the use of ADP to ATP and the cofactors Mg and K

Question 55

What enzyme catalyses this reaction?

Answer 55

Pyruvate Kinase

Question 56

What happens to the Pyruvate (enrol form)

Answer 56

It quickly tautomerizes to keto-pyruvate (giving rise to a large negative delta G)