Module 6 Objectives

Question 1

What are the laws of thermodymamics?

Answer 1

• Energy cannot be created or destroyed
• Conversion of one form of energy into another always leads to a loss of energy, typically, in the form of heat
• A highly organized system contains a lot of potential energy while a system that is disorganized (high chaos = entropy) contains a low amount of potential energy)

Question 2

What is metabolism?

Answer 2

The sum of all biochemical reactionsin a cell or organism.
metabolism = catabolism + anabolism

Question 3

What is catabolism?

Answer 3

The sum of all degradative reactionsin a cell or organism.

Generate energy (ATP, heat) and oxidize carbon (electrons to NAD+, NADP+, and FAD);
Large —> small

Question 4

What is anabolism?

Answer 4

The sum of all biosynthetic reactionsin a cell or organism.

Require energy (ATP) and reduce carbon (electrons from NADH, NADPH and FADH2)
Small —> large

Question 5

What is the formula for Photosynthesis (Phototrophs)?

Answer 5

6 CO2 + 6 H2O + Sunlight —–> C6H12O6

Question 6

What is the formula for Cellular Respiration (Heterotrophs)?

Answer 6

C6H12O6 —-> 6 CO2 + 6 H2O + ATP

Question 7

What are the steps of macronutrients to ATP?

Answer 7

Catabolism of proteins, fats, and carbohydrates in the three stages of cellular respiration.

Stage 1: oxidation of fatty acids, glucose, and some amino acids yields acetyl-CoA.
Stage 2: oxidation of acetyl groups in the citric acid cycle includes four steps in which electrons are abstracted. S
tage 3: electrons carried by NADH and FADH2 are funneled into a chain of mitochondrial (or, in bacteria, plasma membrane–bound) electron carriers — the respiratory chain — ultimately reducing O2 to H2O. This electron flow drives the production of ATP.

Question 8

What is glucose catabolism?

Answer 8

• The ‘splitting’ of ‘sugar’
• Partial oxidation of C (—> NADH)
• ATP (small amount)
• Primary source of metabolic energy in some mammalian tissues and cell types (brain, red blood cells, anaerobic muscle, sperm,…)
• Two-phase process
• Many enzymes of glycolysis are Mg2+-dependent

10 enzymatic steps (make 2 NADH and 2 ATP
Glucose (C6) —-> 2 pyruvate (C3)

Question 9

What is kinase?

Answer 9

Catalyze transfer of a phosphate group from one organic molecule to another, usually involving ADP or ATP (most of these are non-reversible)

Question 10

What is Phosphatase?

Answer 10

Remove a phosphate group, yielding inorganic phosphate (Pi)

Question 11

What is Isomerase?

Answer 11

Catalyze the formation of an isomer of the substrate (requires the breaking of a bond, reversible reactions)

Question 12

What is Dehydrogenase?

Answer 12

Catalyze redox reactions (coenzyme NAD+/NADH, FAD/FADH2 or NADP+/NADPH)

Question 13

What is the TCA cycle?

Answer 13

8 intermediates (metabolites)
8 enzymes
- 4 Dehydrogenases(2 catalyze an oxidative decarboxylation)
Location: Matrix of mitochondria

Yield per acetyl-CoA:
- 2 CO2 (waste)
- 3 NADH
- 1 FADH2
- 1 ATP

Question 14

What is oxidative phosphorylation?

Question 15

What is fatty acid catabolism?

Question 16

What is amino acid catabolism?

Question 17

What is fermentation? How does it work?

Question 18

What are the micronutrient requirements for bioenergentics?

Question 19

What are the structure and function of enzymes?

Answer 19

Stucture:
Enzymes are proteins
Enzymes have an active site that is complementary to the substrate.

Functions:
Enzymes = Biocatalysts
- Increase reaction rate (v0) by lowering the activation energy of a chemical reaction

Question 20

What are examples of alcohol dehydrogenase?

Answer 20

The big picture of alcohol (ethanol) processing in our body (primarily in the liver)

                ADH                ALDH CH3CH2OH ----> CH3CHO ----> CH3COO- 
                     Acetaldehyde       Acetate

Question 21

What is acetaldehyde to the body? What is it quickly converted into?

Answer 21

It is toxic and a known carcinogen; does normally not accumulate as it is quickly converted to acetate.

Question 22

What is acetate used for?

Answer 22

Energy production (TCA cycle and oxidative phosphorylation)
As a building block for fatty acids, stored in the form if triglycerol (fat)

Question 23

What are enzyme kinetics examples?

Question 24

Explain Michaelis-Menten inhibitors.

• Normal binding
• Competitive inhibition
• Mixed inhibition
• Uncompetitive inhibition

Answer 24

• Normal binding: normal substrate in the active site
• Competitive inhibition: different substrate in the active site blocking the normal substrate
• Mixed inhibition: different substrate in a different active site; normal substrate can’t bind because changes the original active site shape
• Uncompetitive inhibition: different substrates on different active site; normal substrate can still bind

Question 25

What is the schematic depiction of inhibitor action?

Answer 25

Competitive: Vmax - unchanged; Km - increases
Mixed: Vmax - decrease; Km - increases (allosteric effect)
Uncompetitive: Vmax - decrease; Km - decreases

Question 26

Explain enzyme regulation beyond the MM-model.

Answer 26

Intracellular can be covalent or non-covalent, but are both reversible

Extracellular are covalent, but non-reversible

Question 27

What are physiological examples of enzyme regulation?

Answer 27

Blood clotting - Beneficial

Blood clotting - pathologies
- Myocardial infarction (heart attack)
- Cerebrovascular Accident (stroke)
- DVT = Deep Vain Thrombosis
- Pulmonary Embolism