Metabolism

Question 1

What is glycolysis?

Answer 1

The conversion of glucose into pyruvate.

Question 2

How do enzymes speed up reactions?

Answer 2

Enzymes speed up reactions by lowering the activation energy..

Question 3

What happens in the link reaction?

Answer 3

• Pyruvate is decarboxylated, Carbon is removed in the form of CO2.
• NAD is reduced to become NADH
• This convert pyruvate to Acetyl CoA.

Question 4

What is the net gain of ATP and reduced NAD in glycolysis?

Answer 4

2 ATP & 2 NADH

2 ATP is used and 4 is produced

2 NADH is produced.

Question 5

Explain what happens in glycolysis?

Answer 5

• Glucose is phosphorylated by adding 2 phosphates, the result is 2 molecules of triose phosphate.
• Triose phosphate is oxidized as it loses hydrogen, the result is pyruvate.
• NAD collects the 2 hydrogen ions to form 2 NADH.
• 4 ATP is produced. (Net gain od 2 ATP)

Question 6

Where does the krebs cycle take place?

Answer 6

In the Matrix of the mitochondria

Question 7

Explain what happens in the krebs cycle?

Answer 7

• Acetyl CoA (2C) reacts with Oxaloacetate (4C) to form citrate (6C).
• Acetyl CoA goes back to the link reaction to be used again.
• Decarboxylation occurs, 6C Citrate becomes a 5 carbon compound (a-ketoglutarate).
• Decarboxylation occurs again, 5 carbon compound becomes 4 carbon compound.
• 2 NAD’s gets reduced.
• ATP is produced.
• FAD is reduced
• The end product is oxaloacetate, which is used again to do the same cycle.

Question 8

What are the types of inhibitors?

Answer 8

1. Competitive inhibitor
2. Non-competitive inhibitor

Question 9

What does the competitive inhibitor do?

Answer 9

Competes with the substrate for the same active site.

Question 10

What does the non-competitive inhibitor do?

Answer 10

Bind at a different site which alters(affects) the shape of the enzyme.

Question 11

How can the rate of reaction be increased in competitive inhibition?

Answer 11

By increasing the number of substrates, because there is more available substrate than inhibitors.

Question 12

What are some differences between competitive and non-competitive inhibition?

Answer 12

Question 13

What is end-product inhibition?

Answer 13

When the end-product of a reaction allosterically inhibits the first enzyme from starting another reaction.

Question 14

What is an allosteric site?

Answer 14

A binding site on the surface of an enzyme other than the active site. It is also the site where the end-products binds to in an end-product inhibition.

Question 15

Explain the example of isoleucine and threonine.

Answer 15

• Threonine is turned into isoleucine through the help of different enzymes.
• Isoleucine is the final product, which then binds allosterically to the enzyme that catalyses the first step, which means that the substrate can no longer bind to the active site.