biochem basics

Question 1

free energy equation and negative vs positive G

Answer 1

delta G = deltaH - T(delta S)

G= free energy
H = enthalpy
T= temp
negative G reaction is spontaneous (releases energy)
positive G reaction is non spontaneous (requires energy)

Question 2

positive S vs negative S

Answer 2

increases disorder vs lowers disorder

Question 3

formula for enthalpy

Answer 3

deltaH = deltaE + P(deltaV)

E = bond energy of products or reactants in a system
P = pressure 
V= volume

Question 4

what is delta G when Keq is 1

Answer 4

0 because ln 1 = 0 based on equation

Question 5

K’eq

Answer 5

ratio of products to reactants when enough time has passed for equilibrium to be reached

Question 6

Q vs Keq

Answer 6

Q is the ratio of products to reactants in any given set up while K is the ratio at equilibrium

Question 7

two factors that determine whether a reaction will occur spontaneously in the cell

Answer 7

intrinsic properties of reactants and products (Keq)

concentrations of reactants and products (RTlnQ)

Question 8

activation energy

Answer 8

energy required to produce transition state, lowered by catalyst

Question 9

enzymes

Answer 9

don’t affect delta G, lower activation energy, has a kinetic role, not a thermodynamic one

Question 10

oxidation reactions characteristics

Answer 10

gain of oxygen atoms, loss of hydrogen atoms, loss of electrons

Question 11

reduction reactions characteristics

Answer 11

loss of oxygen atoms, gain of hydrogen atoms, gain of electrons

Question 12

catabolism vs anabolism

Answer 12

breaking down molecules vs building up,

anabolic processes are usually reductive

Question 13

acids vs bases

Answer 13

acids - proton donors, electron pair acceptors

bases - proton acceptors, electron pair donors

Question 14

how is strength of acids/bases determined

Answer 14

related to how much the products are favored over the reactants, measured by acid ionization constant Ka

bases - Kb

Question 15

what does a high Ka or Kb indicate

Answer 15

high acidity or basicity

Question 16

amphoteric substance

Answer 16

acts as an acid or a base

Question 17

pH

Answer 17

measures concentration of H+ in a solution, lower pH indicated high conc, which equals higher acidity

Question 18

buffer

Answer 18

solution that resists changing pH when a small amount of acid or base is added

Question 19

bicarbonate buffer system

Answer 19

most important buffer system in our blood plasma, consists of carbonic acid and its conjugate base bicarbonate

for instance, when H+ is produced, reaction will shift to form H2CO3, reducing amount of free H+ ions.