Glycolysis

Question 1

Location of glycolysis

Answer 1

cytoplasm

Question 2

What is glycolysis

Answer 2

A series of reactions that extracts energy from glucose

Question 3

overview of glucose

Answer 3

1. the trapping of glucose molecule by phosphorylation

2. the splitting of glucose molecule into 2

Question 4

steps of glycolysis

Answer 4

1. phosphorylation
2. lysis
3. oxidation/dehydrogenation
4. de-phosphorylation
5. pyruvate is produced

Question 5

first step of glycolysis

Answer 5

• Glucose(hexose 6c) is phosphorylated by 2 ATP to form fructose biphosphate.
• Glucose is a high energy molecule however it is hard to react it. To tap to its bond energy, energy is used to make the reaction is easier.
• Glucose to glucose phosphate (use ATP) to glucose biphosphate to fructose biphosphate( use ATP)

Question 6

Second step of glycolysis

Answer 6

lysis: the splitting of fructose biphosphate to 2 molecules of triose phosphate (3c)

Question 7

Third step of glycolysis

Answer 7

dehydrogentaion or oxidation: hydrogen is removed from the triose phosphate and is transferred to coenzyme carrier molecule NAD to from NADH.

• the Hydrogen in NADH can be transferred easily to other molecules and is also used in oxidative phosphorylation to generate ATP
  formula: 4H + 2NAD = 2NADH + 2H^+

Question 8

fourth step

Answer 8

de-phosphorylation(substrate linked phosphorylation): phosphate from intermediate substrate molecules are transferred to ADP to from ATP. it only accounts for a small amount of ATP

4pi + 4 ADP = 4ATP

Question 9

final products

Answer 9

1. 2 pyruvate molecules
2. A net gain of 2 ATP
3. 2 reduced NAD

Question 10

What happened to pyruvate?

Answer 10

Pyruvate itself still contains a high amount of chemical potential energy. If free oxygen in available, energy can be released from pyruvate via the krebs cycle and oxidative phosphorylation. However, the pyruvate first need to enter the link reaction in the mitochondria

Question 11

Why is glucose converted to hexose biphospahte?

Answer 11

1. Glucose is actually quite stable because of the activation energy that has to be added before any reaction takes place. In living organism, the activation energy is overcome by lowering it using enzymes and also by raising the energy level of glucose by phosphorylation
2. Glucose is not really reactive, hexose biphosphate is unstable and more reactive which makes it easier to split into 2 triose phosphate molecule
3. the addition of the phosphate also traps glucose inside the cell since glucose with a phosphate can’t readily cross the membrane.