Lecture 10 Flashcards

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

how are polymers synthesized

A

dehydration

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

how are polymers broken down

A

hydration

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

what is a catabolic pathway

A

energy is released by the breakdown of complex molecules to simpler compounds; overall ΔG is negative

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

what is an anabolic pathway

A

energy is used to build complicated molecules from simpler ones; overall ΔG is positive

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

what is kinetic energy

A

the energy of an object in motion

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

what is potential energy

A

stored energy

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

what is thermal energy

A

kinetic energy associated with random movement of atoms or molecules

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

what is chemical energy

A

is potential energy availablefor release in a chemical reaction

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

what are the four forms of energy

A

light, electricity, motion, heat

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

what is the first law of thermodynamics

A

Energy can be changed from one form to another, but it cannot be created or destroyed

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

what is the second law of thermodynamics

A

Every energy transfer or transformation increases the disorder (entropy) of the universe

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

what causes a reaction to be spontaneous

A

the products are less ordered than the reactants; the products have less energy than the reactants

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

what does it mean for a reaction to be spontaneous

A

a process that can occur without an input of energy; must increase the entropy of the universe

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

how can a non-sponatanous reaction occur

A

can only occur if energy is added to the system

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

what does it mean when an reaction is exothermic

A

reactions release energy; the products have less potential energy than the reactants; spontaneous; more stable

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

what does it mean when an reaction is endothermic

A

reactions absorb energy; the products have more potential energy than the reactants; not spontaneous; less stable

17
Q

how does a reaction end with a negative delta-G, the system must…

A

give up enthalpy, give up order, or both

18
Q

what is free-energy

A

energy available to do work

19
Q

what is ΔG

A

is a measure of a system’s instability – its tendency to change to a more stable state

20
Q

what type of systems are living organisms

A

open systems

21
Q

what is the ultimate source of energy for most organisms

A

the sun

22
Q

a cell does what three main kinds of work

A

chemical, transport, and mechanical

23
Q

why is ATP important

A

temporarily stores chemical potential energy that drives most cellular work

24
Q

what is phosphorylation

A

Terminal phosphate group is transferred to a reactant molecule involved in an endergonic reaction

25
Q

what are catalysts

A

chemical agent that speeds up a reaction without being consumed by the reaction

26
Q

what is activation energy

A

The initial energy needed to start a chemical reaction is called the free energy of activation

27
Q

how are enzymes beneficial to reactions

A

enzymes reduce activation energy and speed up metabolic reactions

28
Q

what is the active site

A

The substrate interacts with a small pocket or groove in the enzyme molecule

29
Q

how do enzymes lower activation energy

A

Bringing the reacting molecules together; Changing the shape of the substrate molecules; Providing a microenvironment that promotes catalysis; Participating directly in the chemical reaction

30
Q

what determines enzyme activity

A

initial substrate concentration, environmental conditions, cofactors, enzyme inhibitors

31
Q

what are cofactors

A

non-protein helpers

32
Q

what are enzyme inhibitors

A

competitive and noncompetitive

33
Q

what are competitive inhibitors

A

they bind to the active site of an enzyme, competing with the substrate- can be overcome by increase [substrate]

34
Q

what are noncompetitive inhibitors

A

they bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective

35
Q

what is allosteric regulation

A

Enzyme’s function at one site is affected by the binding of a regulatory molecule at another site; activation and inhibitors

36
Q

what is feedback inhibition

A

End product switches off the metabolic pathway

37
Q

what is allosteric activation

A

enzyme binds allosteric activators; binding activator converts enzyme to high-affinity state; in high-affinity state, enzyme binds substrate

38
Q

what is allosteric inhibition

A

enzyme binds allosteric inhibitor, binding inhibitor converts enzyme to low-affinity state; substrate is released

39
Q

why is feedback inhibition important

A

prevents a cell from wasting chemical resources