Chapter 4

Question 1

metabolism

Answer 1

sum total of all chemical rxns that occur in cell

Question 2

catabolic rxns

Answer 2

energy releasing metabolic rxns

Question 3

anabolic rxns

Answer 3

energy requiring metabolic rxns

Question 4

nutrients

Answer 4

supply of monomers (or precursors) required by cells for growth

Question 5

macronutrients

Answer 5

nutrients required in large amounts

Question 6

micronutrients

Answer 6

nutrients required in trace amounts

Question 7

carbon

Answer 7

1. required by all cells
2. typically bacterial cell is 50% carbon (dry weight)
3. major element in all classes of macromolecules
4. heterotrophs use organic carbon
5. autotrophs use inorganic carbon

Question 8

nitrogen

Answer 8

1. typical bacterial cell is 12% nitrogen

2. key element in proteins, nucleic acids

Question 9

phosphorous

Answer 9

synthesis of nucleic acids and phopholipids

Question 10

sulfur

Answer 10

sulfur containing amino acids, vitamins, coenzyme A

Question 11

potassium

Answer 11

required by enzyme for activity

Question 12

magnesium

Answer 12

1. stabilizes ribosomes, membrane and nucleic acids

2. required for many enzymes

Question 13

calcium

Answer 13

1. helps stabilize cell walls in microbes

2. plays key role in heat stability of endospores

Question 14

sodium

Answer 14

required by some microbes

Question 15

iron

Answer 15

1. key component of cytochromes and FeS proteins involved in electron transport
2. anoxic conditions –> ferrous (Fe2+) form, exists as insoluble materials
3. oxic conditions –> ferric (Fe3+) form, exists as insoluble minerals
4. cells produce siderophores to obtain iron from insoluble mineral form

Question 16

siderophores

Answer 16

iron binding agents

Question 17

growth factors

Answer 17

organic compounds require in small amounts by certain organisms (vitamins, aa, purines, pyrimidines)

Question 18

vitamins

Answer 18

most commonly required growth factor, function as coenzyme

Question 19

culture media

Answer 19

nutrient solutions used to grow microbes in lab

Question 20

defined media

Answer 20

precise chemical composition is known

Question 21

complex media

Answer 21

composed of digests of chemically undefined substances (yeast, meat extracts)

Question 22

selective media

Answer 22

contains compounds that selectively inhabit growth of some microbes but not others

Question 23

differential media

Answer 23

contains indicator (dye) that detects particular chemical rxns during growth

Question 24

pure culture

Answer 24

culture containing only a single kind of microbe

Question 25

contaminants

Answer 25

unwanted organisms in culture

Question 26

cells can be grown in _______ or _______

Answer 26

liquid, solid culture media

Question 27

pure culture technique

Answer 27

streak plate, pour plate, spread plate

Question 28

free energy

Answer 28

energy released that is available to do work

Question 29

delta G

Answer 29

change in free energy during a rxn

Question 30

exergonic

Answer 30

reactions w/ negative delta G

Question 31

endergonic

Answer 31

reactions w/ positive delta G

Question 32

free energy of formation

Answer 32

energy released or required during formation of given molecule from elements

Question 33

activation energy

Answer 33

energy required to bring all molecules in a chemical reaction into reactive state

Question 34

catalyst

Answer 34

substance that lower activation energy of reaction, increases reaction rate, does not affect energetics or equilibrium of reaction

Question 35

redox reactions

Answer 35

oxidation-reduction

Question 36

energy from redox rxns is used in synthesis of _______

Answer 36

energy-rich compounds

Question 37

electron donor

Answer 37

substance oxidized in redox reaction

Question 38

electron acceptor

Answer 38

substance reduced in redox reaction

Question 39

two classes of electron carriers

Answer 39

prosthetic groups, coenzymes

Question 40

prosthetic groups

Answer 40

attached to enzymes

Question 41

coenzymes

Answer 41

diffusable (NAD+, NADP)

Question 42

_______ and _______ facilitate redox rxns without being consumed, they are recycled

Answer 42

NAD+, NADH

Question 43

chemical energy released in redox rxns primarily stored in certain _______

Answer 43

phosphorylated compounds (ATP, phosphoenolpyruvate, glucose 6-phosphate)

Question 44

long term energy storage involves insoluble polymers that can b oxidized to generate _______

Answer 44

ATP (glycogen, sulfur in prokaryotes; starch and lipids in eukaryotes)

Question 45

two reaction series linked in energy conservation in chemoorganotrophs

Answer 45

fermentation, respiration

Question 46

fermentation

Answer 46

substrate-level phosphorylation; ATP directly synthesized from energy-rich intermediate

Question 47

respiration

Answer 47

oxidative phosphorylation; ATP produced from proton motive force by transport of electrons

Question 48

glycolysis (embden-meyerhof)

Answer 48

common pathway for catabolism of glucose, anaeorbic process, three stages

Question 49

glycolysis

Answer 49

glucose consumed, two ATPs produced, fermentation products generated (some harnessed by humans for consumption)

Question 50

aerobic respiration

Answer 50

oxidation using O2 as terminal electron acceptor, higher ATP yield than fermentations

Question 51

electron transport system

Answer 51

membrane associated, medicate transfer of electrons, conserve some energy released during transfer and use it to synthesize ATP, redox enzymes are involved in electron transport

Question 52

NADH dehydrogenases

Answer 52

proteins bound to inside surface of cytoplasmic membrane; active site binds NADH and accepts 2 electrons and 2 protons that are passed to flavoproteins

Question 53

flavoproteins

Answer 53

contains flavin prosthetic group that accepts 2 electrons and 2 protons and donated electrons to next protein in chain

Question 54

cytochromes

Answer 54

proteins contain heme prosthetic groups, accept and donate a single electron via the iron atom in heme