Glycosis

Question 1

What do cells use instead since they cannot use glucose directly by cells as a source of energy?

Answer 1

Cells use ATP as their immediate energy source

Formation of ATP from the break down of glucose takes place during cellular respiration

Question 2

What are the two types of cellular respiration?

Answer 2

• Aerobic respiration
• Anaerobic respiration

Question 3

What are the properties of aerboic respiration?

Answer 3

• Requires oxygen
• More efficient (more ATP per molecule of glucose)
• Produces CO2 and water - much more ATP - complete breakdown of glucose to CO2
• Slow

Question 4

What are the properties of anerboic respiration?

Answer 4

• Takes place in absence of oxygen
• Less efficient
• Incomplete breakdown of glucose

Question 5

What does anerboic respiration produce in animals?

Answer 5

Lactate

Question 6

What does anaerboic respiration produce in plants and fungi/yeast?

Answer 6

Ethanol and carbon dioxide

Question 7

What are the four stages of aerboic respiration?

Answer 7

• Glycosis
• Link reaction
• Krebs cycle
• Oxidative phosphorylation

Question 8

What is glycosis?

Answer 8

The spilitting of a 6-carbon glucose molecule into two 3-carbon pyruvate molecules

Question 9

What is the link reaction?

Answer 9

3-carbon pyruvate molecules enter in a series of reactions which leads to the formation of acetlycoenzyme A (2-carbon molecule)

Question 10

What is the Krebs cycle?

Answer 10

Introduction to acetlycoenzyme A into the cycle of oxidation reactions that yield some ATP and a large quantity of reduced NAD and FAD

Question 11

What is oxidative phosphorylation?

Answer 11

Use of electrons associated with reduced NAD and FAD released from the Krebs cycle to synthesis ATP with water produced as a by-product

Question 12

What is glycosis inital stage for?

Answer 12

Aerobic respiration

and

anaerobic respiration

Question 13

Where does glycosis occur?

Answer 13

Cytoplasm of all living cells

Question 14

What are the four main stages of glycosis?

Answer 14

• Phosphorylation of glucose to glucose phosphate
• Spiltting of the phosphorylated glucose
• Oxidation of triose phoshphate
• Production of ATP

Question 15

First step of glycosis

phosphorylation of glucose to glucose phosphate

Answer 15

Before it can spilt into two, glucose must be made more reactive by the addition of two phosphate molecules (phosphorylation)

The phosphate molecules come from the hydrolysis of two ATP molecules to ADP

This provides the energy to activate glucose to lower the activation energy for the enzyme-controlled reaction that follows

Question 16

Second step

Spiltting of the phosphorylated glucose

Answer 16

Each glucose molecule is spilt into two 3-carbon molecules known as triose phosphate

Question 17

Third step

Oxidation of triose phosphate

Answer 17

Hydrogen is removed from each of the two triose phosphate molecules and transferred to a hydrogen-carrier molecule known as NAD as to form reduced NAD

Question 18

Four step

Production of ATP

Answer 18

Enzyme-controlled reactions convert each triose phosphate into another 3-carbon molecules called pyruvate

In this process, two molecules of ATP are regenerated from ADP

Question 19

Overall net yield/gain from one glucose molecule undergoing glycosis

Answer 19

• two molecules of ATP
• Two molecules of reduced NAD
• Two molecules of pyruvate

Question 20

Why are two molecules of ATP net yield/gain?

Answer 20

Four molecules of ATP are produced, but two are used up in inital phosphorylation of glucose

net increase is two molecules

Question 21

Why does glycosis provide indirect evidence for evolution?

Answer 21

Universal feature of every living organisms

Question 22

Why does glycosis require any organelle or membrane for it to take place?

Answer 22

The enzymes for glycoytic pathway are found in the cytoplasm in cells

Question 23

Diagram of glycosis

Answer 23