Intro to Metabolism

Question 1

Cellular Combustion Pathways

Answer 1

TCA and Oxidative Phosphorylation

Question 2

O2 not involved in Kreb’s Cycle but ?

Answer 2

it doesn’t proceed without O2 usage in ETC (strictly aerobic both)

Question 3

Where do glycolysis and gluconeogenesis occur?

Answer 3

Cytosol

Question 4

Properties of a living system?

Answer 4

1- Self-regenerating 
2- Obeys Physiochemical laws ( CO2, ammonium, and water recycling) 
3- Highly Organized
4- Utilize and generate energy
5- Open and Dynamic system

Question 5

Only form of energy used at 37 degrees ?

Answer 5

Only ATP is used isothermally

Question 6

Define Open Dynamic System?

Answer 6

exchange with environment and constantly changing 9efflux and influx) while maintaining homeostasis

Question 7

What is meant by all molecules as steady state?

Answer 7

Constant concentration because rate of breakdown in pathways should be equal to the rate of synthesis.

Question 8

Example of dynamic system

Answer 8

You have a pool of water with an outlet and inlet where the inflow rate is equal to the outflow rate, and you add dye to your pool of water. The level of water in the pool remains the same, but the intensity of color of the pool of water decreases due to water being recycled.

Question 9

Is steady state equilibrium?

Answer 9

No equilibrium is closed system of reversible reactions only where Keq is constant and doesn’t change. Also DeltaG =0 indicating no work can be done.
Steady State: open dynamic system of rev and irreversible reactions where concentrations can change and then return to basal line. DeltaG not = to 0 so work can be done.

Question 10

Two experiments that proved to us that a living system is dynamic ?

Answer 10

Schoenheimer and ATP daily Requirement

Question 11

What bonds are between ATP phosphates?

Answer 11

3 phosphate residues linked by anhydride bonds.

Question 12

ATP is a high energy molecule implying that…

Answer 12

the products are more stable than reactants (favorable rxns)

Question 13

Reactivity of a molecule doesn’t mean that…

Answer 13

it is stable or requires a lot of energy to break the bond

Question 14

What are reducing equivalents?

Answer 14

NADH and FADH2

Question 15

Relationship btw Q and Keq ?

Answer 15

Q = Keq => ΔG = 0; We are at equilibrium
Q < Keq => ΔG < 0; The reaction is spontaneous
Q > Keq => ΔG > 0; The reaction is spontaneous in the opposite direction.

Question 16

Standard Conditions

Answer 16

1 mole of compounds under standard state: 37 ºC, 1 atm Pressure, 1 M concentration and pH = 7:

Question 17

Eq of free energy at Standard Conditions

Answer 17

ΔG0’ = -RT ln Keq
• Keq < 1 ([C] and [D] are low at equilibrium => Not much of the S is transformed into P when equilibrium is reached) => ΔG0’ +ve => rxn is endergonic.
• Keq > 1 ([C] and [D] are high at equilibrium => Most S is transformed into P when equilibrium is reached) => ΔG0’ -ve => rxn is exergonic and spontaneous.

Question 18

Free Energy equation when reaction starts

Answer 18

ΔG =ΔG0’+ RT ln Q=RT ln Q/Keq

Question 19

Magnesium is needed for?

Answer 19

To prevent the degradation of ATP because it is highly reactive.