Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT-BIOCHEMISTRY > Biochemistry Basics > Flashcards

Biochemistry Basics Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
1
Q

what are the two relevant forms of energy in chemistry?

A

kinetic energy (movement of molecules) and potential energy (energy stored in chemical bonds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

First Law of Thermodynamics/Law of Conservation of Energy

A

The energy of the universe is constant; if the energy of a system decreases, the energy of the system must increase and vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Second Law of Thermodynamics

A

Entropy (disorder) of the universe tends to increase; spontaneous reactions tend to increase the disorder of the universe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

entropy

A

S, disorder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

enthalpy

A

H, bond energy, delta H=delta E+(P*delta V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

spontaneous

A

delta G is negative, reaction is favourable, occur without a net addition of energy and have energy to spare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

non-spontaneous

A

delta G is positive, reaction is unfavourable, requires energy input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

exergonic

A

energy exits the system, describes reactions with negative change in free energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

endergonic

A

reaction requires energy input, describes reactions with positive change in free energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how are endergonic reactions completed in the body?

A

by reaction coupling to exergonic reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

exothermic

A

reactions with a negative change in enthalpy, releases heat into the surroundings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

endothermic

A

reactions with a positive change in enthalpy, requires input of heat from the surroundings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

in which direction of free energy does a system always move?

A

towards lowest free energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does the value of delta free energy depend on?

A

the concentration of reactants and products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

delta G naught=

A

standard free energy with all reactants and products at 1M concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

delta G naught prime=

A

1M concentration of all solutes except H+ and a pH of 7, standardized for human physiological conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the formula for delta G naught prime?

A

= -RTlnKeq’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the formula for delta G (real life)?

A

=delta G naught prime + RTlnQ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

equilibrium

A

the point where the rate of reaction in the forward direction equals the rate of reaction in the reverse direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

if a system in equilibrium is disturbed (ex. by adding excess reactant or product), will the value of K change?

A

no, but the value of Q will change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the two factors that determine whether a reaction will occur spontaneously (negative free energy change) in the cell?

A

1) the intrinsic properties of the reactants and products (K)
2) the concentration of reactants and products (RTlnQ)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

do all spontaneous reactions occur rapidly?

A

no, spontaneous means a reaction is energetically favourable (thermodynamics) but says nothing about rate of reaction (kinetics)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

does free energy change depend on the reaction pathway?

A

no, it is only a measurement of the difference in free energy between reactants and products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

chemical kinetics

A

the study of reaction rates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

why are some spontaneous (thermodynamically favourable) reactions slow to proceed or do not proceed at all?

A

because of a large activation energy barrier

26
Q

transition state (TS)

A

unstable state that all reactions proceed through, takes large amounts of energy to produce

27
Q

activation energy Ea

A

the energy required to produce the transition state

28
Q

what is the barrier that prevents many reactions from proceeding (even thermodynamically favourable ones)?

A

activation energy

29
Q

what determines the kinetics of a reaction?

A

activation energy

30
Q

catalyst

A

lowers the activation energy of a reaction without changing the free energy change by stabilizing the transition state, it is regenerated with each reaction cycle

31
Q

enzymes

A

biological catalysts that lower Ea without changing delta G

32
Q

what kind of role do catalysts (enzymes) have?

A

a kinetic role, NOT a thermodynamic one

33
Q

photosynthesis

A

the process by which plants store energy from the sun in the bond energy of carbohydrates

34
Q

photoautotrophs

A

generate energy from light to make their own food ex. plants

35
Q

chemoheterotrophs

A

use energy of food/chemicals produced by other living things ex. humans

36
Q

oxidation

A

loss of electrons

37
Q

reduction

A

gain of electrons

38
Q

what determines whether a molecule is oxidized or reduced?

A

it depends on the other atoms that they are bound to

39
Q

what is indicative of oxidation reactions?

A

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

40
Q

what is indicative of reduction reactions?

A

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

41
Q

redox pair

A

describes the pair resulting from oxidation/reduction; when one atom gets reduced, another one must be oxidized

42
Q

catabolism

A

the process of breaking down molecules

43
Q

anabolism

A

the process of building up molecules

44
Q

what is the term to describe the process of extracting energy from glucose to produce CO2 and H2O?

A

oxidative catabolism

45
Q

are anabolic processes generally reductive or oxidative?

A

reductive

46
Q

Bronsted-Lowry acid

A

proton donors

47
Q

Bronsted-Lowry base

A

proton acceptors

48
Q

Lewis acid

A

electron-pair acceptors

49
Q

Lewis base

A

electron-pair base

50
Q

what is the relationship between acid-ionization constant Ka and acidity?

A

the larger the Ka, the stronger the acid; the smaller the Ka, the weaker the acid

51
Q

what is the relationship between base-ionization constant Kb and basicity?

A

the larger the Kb, the stronger the base; the smaller the Kb, the weaker the base

52
Q

polyprotic

A

molecules with more than one proton to donate

53
Q

amphoteric

A

substances that can act as either an acid or a base

54
Q

evertime a polyprotic acid donates a proton, what is the effect on acidity of the resulting species?

A

the resulting species will be a weaker acid than its predecessor

55
Q

low pH means:

A

higher [H+] and the solution is acidic

56
Q

high pH means:

A

lower [H+] and the solution is basic

57
Q

what is the relationship between pKa and acidity?

A

lower pKa = stronger acid

58
Q

what is the relationship between pKb and basicity

A

lower pKb=stronger base

59
Q

buffer

A

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

60
Q

what does a buffer consist of?

A

presence of a weak acid and its conjugate base (or weak base and its conjugate acid) in roughly equal concentrations

61
Q

what is the most important buffer system in our blood plasma?

A

the bicarbonate buffer system: H2CO3—>H+ + HCO3-

MCAT-BIOCHEMISTRY (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions