Micro Lecture 4

Front 1

Metabolism

Back 1

Sum total of all reactions in a cell

Front 2

Catabolic

Back 2

Energy releasing

Front 3

Anabolic

Back 3

Energy requiring

Front 4

Nutrients

Back 4

Monomers required for growth

Front 5

Macronutrients

Back 5

Carbon nitrogen potassium phosphorus magnesium calcium sodium

Front 6

Micronutrients

Back 6

Iron

Front 7

Growth factors

Back 7

Organic compounds required in small amounts by certain organisms. examples: vitamins, amino acids, purines, pyrimidines

Front 8

Vitamins

Back 8

Most commonly required growth factor. most function as coenzymes

Front 9

Culture media

Back 9

Nutrient solutions. Two broad classes: defined media and complex media

Front 10

Defined media

Back 10

Precise chemical composition is known

Front 11

Complex media

Back 11

Digests of chemically undefined substances. (Yeast and meat extracts)

Front 12

Selective media

Back 12

Inhibits the growth of some organisms but not others

Front 13

Differential media

Back 13

Contains an indicator, usually a dye, that detects particular chemical reactions occurring during growth

Front 14

Pure culture

Back 14

Contains a single kind of microbe

Front 15

Contaminants

Back 15

Unwanted organisms in a culture

Front 16

Organisms can be grown in...

Back 16

Liquid or solid culture media

Front 17

Solid media is prepared by...

Back 17

Addition of a gelling agent ( agar or gelatin)

Front 18

When grown on solid media, cells form...

Back 18

Isolated masses (colonies)

Front 19

Pure culture techniques

Back 19

Streak plate, pour plate, spread plate

Front 20

Free energy (G)

Back 20

Energy released that is available to do work

Front 21

The change in free energy during the reaction is referred to as...

Back 21

Delta G not prime

Front 22

Reactions with a negative Delta G not prime...

Back 22

Released free energy and are exergonic

Front 23

Reactions with a positive Delta G not prime...

Back 23

Require energy and are endergonic

Front 24

Energy is defined in units of...

Back 24

Kilojoules, a measure of heat energy

Front 25

Free energy calculations do not provide information on...

Back 25

Reaction rates

Front 26

Activation energy

Back 26

Energy required to bring all molecules in a chemical reaction into the reactive state. A catalyst is usually required to breach the activation energy barrier

Front 27

Catalyst

Back 27

A substance that

- lowers the activation energy of a reaction

- increases reaction rate

- does not affect energetics or equilibrium of reaction

Front 28

Enzymes

Back 28

Biological catalysts

typically proteins

highly specific

generally larger than substrate

typically rely on weak bonds

Front 29

Active site of an enzyme

Back 29

Region that binds substrate

Front 30

Enzymes increase the rate of chemical reactions by...

Back 30

10^8 to 10^20 times the spontaneous rate

Front 31

Catalysts are dependent on

Back 31

Substrate binding, position of substrate relative to catalytically active amino acids in active site

Front 32

Many enzymes contain small non protein molecules that...

Back 32

Participate in catalysis but are not substrates

Front 33

Prosthetic groups

Back 33

Bind tightly to enzymes and usually bind covalently and permanently (heme)

Front 34

Coenzymes

Back 34

Loosely bound to enzymes, most are derivatives of vitamins (nad+/nadh)

Front 35

Electron donor

Back 35

The substance oxidized in a redox reaction

Front 36

Electron acceptor

Back 36

The substance reduced in a redox reaction

Front 37

Redox couple

Back 37

Can be either electron donors or acceptors under different circumstances

Front 38

Reduced substance of a redox couple with a more negative reduction potential...

Back 38

Donates electrons to the oxidized substance of a redox couple with a more positive reduction potential

Front 39

Chemical energy released in redox reactions is primarily stored in...

Back 39

Certain phosphorylated compounds

Front 40

To reaction series are linked to energy conservation in chemoorganotrophs

Back 40

Fermentation and respiration

Front 41

Fermentation

Back 41

Substrate level phosphorylation, ATP directly synthesized from an energy rich intermediate

Front 42

Respiration

Back 42

Oxidative phosphorylation, ATP produced from proton motive force formed by transport of electrons

Front 43

Three major steps of glycolysis

Back 43

Glucose consumed, 2 ATPs produced, fermentation products generated

Front 44

Aerobic respiration

Back 44

Oxidation using o2 as the terminal electron acceptor, and higher yield ATP than fermentations

Front 45

Electron transport systems

Back 45

Membrane-associated, mediate transfer of electrons, conserve some of the energy released during transfer and use it to synthesize ATP, many oxidation reduction reactions are involved in electron transport

Front 46

NADH dehydrogenases

Back 46

Proteins bound to the inside surface of cytoplasmic membrane, active site binds NADH and accepts two electrons and two protons that are passed to flavoproteins

Front 47

Flavoproteins

Back 47

Contains flavin prosthetic group that accepts two electrons and two protons but only donates the electrons to the next protein in the chain

Front 48

The proton motive force

Back 48

Results in generation of pH gradient and an electrochemical potential across the membrane. The inside becomes electrically negative and alkaline, and the outside becomes electrically positive and acidic

Front 49

ATP synthase

Back 49

Converts proton motive force into ATP, has two components.

Reversible, dissipates proton motive force.

Front 50

The two components of ATP synthase

Back 50

F1: Multi protein extra membrane complex, faces cytoplasm

F0: proton-conducting intramembrane channel

Front 51

The citric acid cycle

Back 51

Pathway through which pyruvate is completely oxidized to co2. Initial steps same as glycolysis. Per glucose molecule 6 co2 molecules released and NADH and FADH generated

Plays a key role in catabolism and biosynthesis

Front 52

Methods of energy generation by microorganisms

Back 52

Fermentation, aerobic respiration, anaerobic respiration, chemolithotrophy, phototrophy.

Front 53

Anaerobic respiration

Back 53

The use of electron acceptors other than oxygen (nitrate, carbonate, etc.);

Less energy released compared to aerobic respiration;

Dependent on electron transport, generation of a proton motive force, and ATPase activity.

Front 54

Chemolithotrophy

Back 54

Uses inorganic chemicals as electron donors (H2S, Fe2+, NH3...)

Typically aerobic

Begins with oxidation of inorganic electron donors

Uses electron transport chain and proton motive force

Autotrophic: uses co2 as carbon source

Front 55

Phototrophy

Back 55

Uses energy as a light source

Front 56

Photophosphorylation

Back 56

Light mediated ATP synthesis

Front 57

Photoautotrophs

Back 57

Use ATP for assimilation of co2 for biosynthesis

Front 58

Photoheterotrophs

Back 58

Use ATP for assimilation of organic carbon for biosynthesis