Glycolysis

Question 1

Where does glycolysis take place in the cell?

Answer 1

Cytoplasm

Question 2

What is a molecule with a six membered ring generally known as?

Answer 2

Pyranose

Question 3

What is a molecule with a five membered ring generally known as?

Answer 3

Furanose

Question 4

What happens in a transamination reaction?

Answer 4

An amino group is transferred from one molecule to another (commonly from an amino acid to a keto acid)

Question 5

What is broken down during phosphorylation in glycolysis?

Answer 5

ATP into ADP & Pi (inorganic phosphate molecule)

Question 6

Why does the phosphorylation of glucose need to occur initially?

Answer 6

Phosphorylated form of glucose is ionised and therefore is trapped in the cell

Question 7

What is NAD made up of?

Answer 7

Nicotinamide, ribose x2, adenine (ribose + adenine = adenosine)

Question 8

Why is vitamin B3 so crucial in glycolysis?

Answer 8

It is extremely important in the manufacture of nicotinamide

Question 9

Under aerobic conditions, what happens to the NADH produced?

Answer 9

It is sent to the electron transfer chain where it loses its H+, setting up a proton gradient which drives ATP synthase to manufacture ATP; when the hydrogen ion returns, it reacts with the final elector acceptor, oxygen, to produce water, which is then expelled from the cell. The remaining NAD- is recycled back to the start of the glycolysis reaction

Question 10

Under anaerobic conditions, what happens to the NADH produced?

Answer 10

Due to the absence of a final electron acceptor (oxygen), the NADH is broken down to NAD in the reaction turning pyruvate into lactate, and recycled so that the process of glycolysis can continue, despite the anaerobic conditions

Question 11

What part does hexokinase play in the rate regulation of glycolysis?

Answer 11

Glucose —> Glucose-6-Phosphate

Question 12

What part does phosphofructokinase play in the rate regulation of glycolysis?

Answer 12

Fructose-6-Phosphate —> Fructose-1,6-Bisphosphate

Question 13

What part does pyruvate kinase play in the rate regulation of glycolysis?

Answer 13

Phosphoenolpyruvate —> Pyruvate

Question 14

What is meant by the term ‘allosteric inhibition’?

Answer 14

Inhibition of an enzyme by binding to a site distant to its active site, but causing a conformational change in its structure so that it can’t bind to a substrate

Question 15

Name three factors that inhibit the phosphofructokinase enzyme

Answer 15

High concentration of citric acid
High concentration of ATP
Low pH

Question 16

Name one factor that stimulates the phosphofructokinase enzyme

Answer 16

High concentration of fructose-6-phosphate