Lecture #18: Background To Biochemistry

Question 1

Oxidation- reduction reaction

Answer 1

A^0 + B^0 —-> A^+ + B^+
A^+ = oxidized state, reduced energy
B^+ = reduced state, increase energy

Question 2

Exergonic/exothermic reation

Answer 2

A + B —> C+D + energy

Question 3

Endergonic/endothermic reaction

Answer 3

M + N + energy —> O + P

Question 4

Catalyst

Answer 4

1. speeds up a chemical reaction
2. without being changed in the process

Question 5

Enzyme

Answer 5

Most important in biology
protein catalyst
- 3-D shape
- lowers activation energy
Affected by:
- temperature
- pH

Question 6

Ribosomes

Answer 6

RNA catalyst

Question 7

Allosteric enzymes

Answer 7

enzyme that changes effectiveness based on changing shape when a molecule binds to it
2 ways that it works (both changes shape of enzyme):
1. Activators
2. Inhibitors

Question 8

Activators

Answer 8

bind to inactive enzyme to activate it

Question 9

Inhibitors

Answer 9

bind to active enzyme to inactivate it

Question 10

Control of chemical reactions

Answer 10

1. increase the amount of reactants
2. increase the amount of enzyme
3. increase the amount of activator for allosteric enzyme

Question 11

Biochemical pathway

Answer 11

starting molecule –> Intermediate –> Intermediate –> product (used up by cell activity) –> back to starting molecule
- if product inhibits an enzyme = self-regulating process (endproduct inhibition/feedback inhibition)

Question 12

Co enzymes

Answer 12

Non-proteins, helpers for enzymatic reactions

Question 13

NAD+

Answer 13

• oxidized form
• less energetic
• electron acceptor

Question 14

NADH

Answer 14

• reduced form
• more energetic
• electron doner

Question 15

NAD+ + 2H —> NADH + H+

Answer 15

NAD+ —> NADH = reduction

Question 16

Create ATP

Answer 16

NADH can donate 2e- to an electron transport chain

e- passed through a chain of molecules (in membrane) - energy from e- is used to pump protons (H+) across the membrane (Build up high conc. of H+)

Then the H+ diffuse back through a coupled channel to create ATP

Question 17

Oxidative phosphorylation

Answer 17

ADP + free phosphate –> ATP
- endergonic process (uses energy)

Question 18

Substrate phosphorylation

Answer 18

ADP + strip a phosphate from another molecule –> ATP
- exergonic process (releases energy)

Question 19

Energy

Answer 19

to maintain order of complex structure (or living organisms), there must be a constant input of energy

Question 20

If a system is left on its own

Answer 20

Complex –> Simple
More order –> less order
more energetic molecules
–> less energetic molecules

Question 21

What law of thermodynamics is this?

Answer 21

2nd - law of entropy
- entropy = disorder (measure of disorder)

Question 22

Photosynthesis

Answer 22

6 CO2 + 6H2O (sunlight)—> C6H12O6 (carbohydrate) + 6 O2
- endergonic process

Question 23

Cellular respiration

Answer 23

C6H12O6 + 6 O2 —> 6 CO2 + 6 H2O + energy (ATP)
- exergonic process