Intro To Metabolism

Question 1

What is the purpose of enzyme regulation?

Answer 1

Enzymes accelerate each step, regulating supply and demand

Question 2

What are catabolic pathways ?

Answer 2

Catabolic pathways release energy by breaking down complex molecules to simpler compounds

This energy is stored in organic molecules until need to do work in the cell

Question 3

What are anabolic pathways ?

Answer 3

Anabolic pathways consume energy to build complicated molecules from simpler compounds

The energy released by catabolic pathways is used to drive anabolic pathways

Question 4

What is reduction?

Answer 4

A chemical reaction in which a molecule gains electrons and energy

The molecule that accepts electrons is reduced

The molecule being reduced receives energy

Question 5

What is oxidation?

Answer 5

A chemical reaction in which a molecule gives up electrons

Oxidation releases energy

The molecule losing the electron is oxidized

Question 6

What is NAD+?

Answer 6

Nicotinamide adenosine dinucleotide(NAD+)

• An electron carrier
• NAD+ accepts 2 electrons and one proton to become NADH
• Reaction is reversible

Question 7

What is NADPH?

Answer 7

-NADPH carries electrons from catabolic pathways to biosynthetic processes ATP

Question 8

Give adjectives of catabolism

Answer 8

Degradation

Convergent

Oxidative

Question 9

What are the products of catabolism?

Answer 9

ATP

FADH2

NADH

NADPH

Question 10

What is the divergent process of anabolism ?

Answer 10

Where a few biosynthetic precursors form a wide variety of complex products

Question 11

How is energy usually provided to anabolism?

Answer 11

Reactions require energy(endergonic) and take energy by breaking down ATP to ADP + Pi

Question 12

Give adjectives for anabolism

Answer 12

• synthesis
• “reductive”
• divergent
• uses ATP

Question 13

What are the products of anabolism?

Answer 13

NAD+

FAD

ADP

NADP+

Question 14

Do catabolism and anabolism have anything in common

Answer 14

A catabolic and an anabolic pathway may share some reaction steps
-Reversal of some enzymatic steps

Question 15

Why are anabolism and catabolism not the exact reverse of each other?

Answer 15

• But… cannot be reverse of each other would create a futile cycle
• Must control the pathways

E.g. glycolysis and gluconeogenesis

Question 16

What are the 3 stages of metabolism/catabolism (comeback for pic)

Answer 16

1. Hydrolysis of complex molecules; broken down into their component building blocks
2. Conversion of building blocks to simple intermediates: these molecules degraded to Acetyl coenzyme A (Acetyl CoA) and other simple molecules
   - Some of this energy is captured as ATP, the energy transfer molecule
3. Oxidation of Acetyl CoA: Tricarboxylic acid cycle is the final common pathway from food to generation of ATP (convergent pathways)
   - TCA generates NADH and FADH2, which carry electrons from TCA, are the substrates for oxidative phosphorylation —-to generate ATP