Brainscape's Knowledge GenomeTM

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


See full index

Microbiology Lecture > Chapter 10 > Flashcards

Chapter 10 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Catabolism

A

the breakdown of a larger molecule into smaller one(s)
Breaks covalent bonds and releases energy, so they are exergonic
Enzyme catalyzed
Most are also oxidations (provides reducing power)
Generates precursors for anabolism

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

Anabolism

A

biosynthesis– the synthesis of a larger molecule from a smaller one or smaller ones
Creates many new covalent bonds and requires energy input so they are endergonic (never endothermic)
Enzyme catalyzed
Mostly reductions

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

Thermodynamics

A

a science that analyzes energy changes in a collection of matter called a system (e.g., a cell)
all other matter in the universe is called the surroundings

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

First Law of Thermodynamics

A

Energy can be neither created nor destroyed
Total energy in universe remains constant
However, energy may be redistributed either within a system or between the system and its surroundings (energy amount can change in a system)

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

Second Law of Thermodynamics

A

Entropy
amount of disorder or randomness in a system
Physical and chemical processes proceed in such a way that the disorder of the universe increases to the maximum possible

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

Calorie

A

amount of heat energy needed to raise 1 gram of water from 14.5 to 15.5°C

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

Joules

A

units of work capable of being done by a unit of energy

1 cal of heat is equivalent to 4.1840 J of work

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

Exergonic

A

chemical reactions with a negative Go′value that release free energy (if heat released it also exothermic)

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

Endergonic

A

chemical rReactions with a positive Go′ value require an energy input (it is never endothermic in biological systems)

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

Role of ATP in Metabolism

A

High energy molecule

Exergonic breakdown of ATP is coupled with endergonic reactions to make them more favorable

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

Oxidation Reduction Reactions

A

Many metabolic processes involve oxidation-reduction reactions (electron transfers)
Electron carriers are often used to transfer electrons from an electron donor to an electron acceptor
Oxidation-reduction reactions also transfer energy with the electrons

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

redox

A

Transfer of electrons from a donor to an acceptor
results in energy release, which can be conserved and used to form ATP
the more electrons a molecule has, the more energy rich it is

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

oxidation

A

the loss of an electron or electrons from an atom, or the loss of an electron, electrons or whole hydrogen atom (2 electrons and 1 proton) from a molecule
Removing electrons or a hydrogen atom removes energy so oxidations are exergonic

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

Reduction

A

the gain of an electron or electrons by an atom, or the gain of an electron, electrons or whole hydrogen atom (2 electrons and 1 proton) by a molecule
Adding electrons or a whole hydrogen atom (bonds) adds energy so reductions are endergonic

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

Redox tower

A

represents the range of possible reduction potentials for redox couples in nature
The reduced substance in the redox couple at the top of the tower has the greatest tendency to donate electrons
The oxidized substance in the redox couple at the bottom of the tower has the greatest tendency to accept electrons
The farther the electrons “drop” from donor to acceptor, the greater the amount of energy released

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

ETC

A

Electron carriers organized into ETC
first electron carrier having the most negative E’o
the potential energy stored in first redox couple is released and used to form ATP
first carrier is reduced and electrons moved to the next carrier and so on

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

Electron carriers

A

Located in cell membranes of chemoorganotrophs in bacteria and archaeal cells
Located in internal mitochondrial membranes in eukaryotic cells
Examples of electron carriers include NAD, NADP, and others

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

NAD

A

nicotinamide adenine dinucleotide

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

NADP

A

nicotinamide adenine dinucleotide phosphate

20
Q

FAD

A

flavin adenine dinucleotide

21
Q

FMN

A

flavin mononucleotide

22
Q

coenzyme Q

A

a quinone

also called ubiquinone

23
Q

Cytochromes

A

use iron to transfer electrons

iron is part of a heme group

24
Q

Nonheme iron-sulfer proteins

A

e.g., ferrodoxin
use iron to transport electrons
iron is not part of a heme group

25
Q

Protein catalysts

A

have a great specicificty for the reaction catalyzed and the molecules acted on

26
Q

Catalyst

A

substrates that increase the rate of a reaction without being permanently altered

27
Q

Substrates

A

reacting molecules

28
Q

Products

A

substances formed by reaction

29
Q

Apoenzyme

A

protein component of an enzyme

30
Q

cofacter

A

ion needed by enzyme

31
Q

nonprotein component of an enzyme

A

prosthetic group-firmly attached. coenzyme-loosely attached

32
Q

haloenzyme

A

apoenzyme and cofacter

33
Q

Activation energy

A

energy required to form transition-state complex

Enzyme speeds up reaction by lowering Ea

34
Q

How enzyme lowers Ea

A

By increasing concentrations of substrates at active site of enzyme
By orienting substrates properly with respect to each other in order to form the transition-state complex
Two models for enzyme-substrate interaction
lock and key and induced fit

35
Q

Effect on enzyme activity

A

substrate concentration
pH
temperature

36
Q

Effect of substrate

A

Rate increases as [substrate] increases

No further increase occurs after all enzyme molecules are saturated with substrate

37
Q

Effect of pH and Temperature

A

Each enzyme has specific pH and temperature optima
Denaturation
loss of enzyme’s structure and activity when temperature and pH rise too much above optima

38
Q

Competitive inhibitor

A

directly competes with binding of substrate to active site

39
Q

Noncompetitive inhibitor

A

binds enzyme at site other than active site

changes enzyme’s shape so that it becomes less active

40
Q

Ribozymes

A 
Thomas Cech and Sidney Altman discovered that some RNA molecules also can catalyze reactions
Examples
catalyze peptide bond formation
self-splicing
involved in self-replication
41
Q

Regulation of Metabolism

A

important for conservation of energy and materials. maintenance of metabolic balance despite changes in env

42
Q

Allosteric Regulation

A

Most regulatory enzymes
Activity altered by small molecule
allosteric effector
binds non-covalently at regulatory site
changes shape of enzyme and alters activity of catalytic site
positive effector increases enzyme activity
negative effector inhibits the enzyme

43
Q

Covalent modification of enzymes

A

Reversible on and off switch
Addition or removal of a chemical group (phosphate, methyl, adenyl)
Advantages of this method
respond to more stimuli in varied and sophisticated ways
regulation on enzymes that catalyze covalent modification adds second level

44
Q

Feedback Inhibition

A

Also called end-product inhibition
Inhibition of one or more critical enzymes in a pathway regulates entire pathway
pacemaker enzyme
catalyzes the slowest or rate-limiting reaction in the pathway

45
Q

isoenzymes

A

different enzymes that catalyzes same reaction

Microbiology Lecture (11 decks)

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