Microbiology Exam 2

Front 1

Metabolism definition

Back 1

the sum of all chemical reactions within a living organism

Front 2

catabolism

Back 2

breaking down complex compounds into simple compounds/ molecules
- proteins into amino acids

Front 3

anabolism

Back 3

building complex molecules from simple molecules
ex: amino acids into proteins

Front 4

5 things to know about enzymes

Back 4

1. are biological catalysts
2. are specific for their substrates; usually 1 enzyme catalyzes only one reaction
3.All apoenzymes (main) are proteins
4. some enzymes need additional chemical components (cofactors)
5. the names of enzymes usually end in -ase

Front 5

2 types of metabolic reactions

Back 5

1. catabolism
2. anabolism
* both involve enzymes and energy

Front 6

T/F
a substrate can have many diff enzymes that can act on it-

Back 6

True
each reaction (and enzyme) may produce a diff product

Front 7

Different types of cofactors

Back 7

-organic cofactor- coenzyme (vitamins)
- inorganic cofactor- metal ions= Fe2+ and Ca2+

Front 8

Factors influencing enzyme activity

Back 8

temperature, pH, substrate concentration

Front 9

Temperature- how does it influence enzyme activitiy

Back 9

heat denatures protein- changes its 3D shape
when cold, substrate and enzyme have to move around to hook up. molecular movement slows when in cold temperatures.

Front 10

pH and enzyme activity

Back 10

ions (H+, OH-) can change 3-D shape resulting in denaturation.
ions compete with chemical bonds in the enzyme

Front 11

Factors influencing enzyme activity

Back 11

temperature, pH, substrate concentration

Front 12

holoenzymes (whole enzymes) consist of

Back 12

apoenzyme, cofactor, and substrate

Front 13

which part of the enzyme is a protein?

Back 13

apoenzyme

Front 14

mechansim of enzyme action: steps

Back 14

1. substrate binds at active site
2. enzyme-substarte complex formed
3. leaves enzyme
4. products come off
5. enzyme with open active site

Front 15

substrate concentration: factor influencing enzyme activity

Back 15

if saturated means: all active sites are filled with substrates.

Front 16

to increase the reaction rate of a saturated enzyme..

Back 16

the cell would have to make more enzyme for the excess substrate

Front 17

what are the 2 types of inhibitors in regards to enzyme activity

Back 17

1. competitive inhibitors
2. noncompetitive inhibitors

Front 18

competitive inhibitors

Back 18

look like the substrate and compete with the substrate for enzymes active site
*no products from inhibitors*

Front 19

noncompetitive inhibitors

Back 19

bind to another site on the enzyme (an allosteric site). binding changes the shape of the active site.
OR
can bind to metal ion cofactors keeping them from helping the enzyme work

Front 20

5 things to know about energy

Back 20

1. catabolic reactions release energy
2. anabolic reactions require energy

Front 21

5 things to know about energy

Back 21

1. catabolic reactions release energy
2. anabolic reactions require energy
3. ATP is the principle energy molecule of the cell
4.ATP is generated in 3 ways from ADP (substrate-level, oxidative, and photophosporylation)
5. energy is released form food in a series of controlled reactions rather than in a simple burst

Front 22

Oxidation

Back 22

loss of electrons

Front 23

reduction

Back 23

gain of electrons

Front 24

to extract energy release from food in controlled series from one compound to another what type of reaction is used?

Back 24

oxidation-reduction reaction

Front 25

when food is catabolized what happens/

Back 25

chemical bonds are broken which release energy

Front 26

when the third phosphate in ATP is removed what happens?

Back 26

usable energy is released

Front 27

substrate-level phosphorylation

Back 27

ATP is generated when a high-energy phosphate is directly transferred from a phosphorylated metabolic intermediate too ADP
(glycolysis)

Front 28

oxidative phosphorylation

Back 28

generation of ATP coupled with electron transport; electrons are passed from carried molecules to O2
(ETC)

Front 29

Photophosphorylation

Back 29

generation of ATP coupled with electron transport in photosynthetic cells
+cells must have light-trapping pigments
+converts light to energy into energy of ATP

Front 30

oxidation-reduction reactions are always coupled. T/F

Back 30

TRUE
each time one substance is oxidized there is another substance which is reduced.

Front 31

what is it called when energy is released in a single burst?

Back 31

combustion

Front 32

Electron carrier molecules include

Back 32

NAD and FAD
both coenzymes

Front 33

NAD nicotinmaide adenine dinucleotide

Back 33

derivative of nicacin (b vitamin)

Front 34

FAD flavin adenine dinucleotide

Back 34

derivative of riboflavin

Front 35

carbohydrate catabolism

Back 35

produce energy from our food.
either by using cellular respiration and/or fermentation

Front 36

what is the first step for both fermentation and cellular respiration?

Back 36

Glycolysis

Front 37

cellular respiration is found where

Back 37

some bacteria= anaerobically respire- dont us oxygen as a final acceptor in ETC

Front 38

what is it called when energy is released in a single burst?

Back 38

combustion

Front 39

Glycolysis

Back 39

Glucose (6 carbons)
(subst levl phosphorylation) 2 ATP (net)- ←--------------------→ 2NADH
V
V
2 Pyruvic Acid (3 carbons)

Front 40

Electron carrier molecules include

Back 40

NAD and FAD
both coenzymes

Front 41

net ATP in glycolysis

Back 41

2 ATP
2 used at beginning, 4 are made, net of 2!

Front 42

NAD nicotinmaide adenine dinucleotide

Back 42

derivative of nicacin (b vitamin)

Front 43

how is ATP made in glycolysis?

Back 43

substrate level phosphorylation

Front 44

FAD flavin adenine dinucleotide

Back 44

derivative of riboflavin

Front 45

carbohydrate catabolism

Back 45

produce energy from our food.
either by using cellular respiration and/or fermentation

Front 46

what is the first step for both fermentation and cellular respiration?

Back 46

Glycolysis

Front 47

cellular respiration is found where

Back 47

some bacteria= anaerobically respire- dont us oxygen as a final acceptor in ETC

Front 48

Glycolysis

Back 48

Glucose (6 carbons)
(subst levl phosphorylation) 2 ATP (net)- ←--------------------→ 2NADH
V
V
2 Pyruvic Acid (3 carbons)

Front 49

net ATP in glycolysis

Back 49

2 ATP
2 used at beginning, 4 are made, net of 2!

Front 50

how is ATP made in glycolysis?

Back 50

substrate level phosphorylation

Front 51

In glycolysis 2, 3-carbon molecule are made which molecule are both converted to to go through?

Back 51

glyceraldehyde 3-phosphate (GP)

Front 52

Preparatory stage of glycolysis (KNOW ALL)

Back 52

1. glucose
2. glucose 6-phosphate (phosph added from ATP)
3. fructose 6-phosphate + addition fo ATP
4. fructose 1,6 diphosphate
5. splits into: dihydroxyacetone phosphate (DHAP) adn Glyceraldehyde 3-phosphate
--only Glyceradehyde are used to go through rest of process

Front 53

energy-conserving stage of glycolysis

Back 53

2 GD oxidized to 2 pyruvic acid
- 4 ATP produced
- 3 NADH produced

Front 54

transition step (glycolysis- kreb)

Back 54

pyruvic acid is oxidized and decarboxylated (COOH is split off as CO2)
- 2 pyruvic acid per lucose result in 2 acetyl CoA per glucose

Front 55

what happens in the transition step

Back 55

3 carbon molecule becomes a 2 carbon

Front 56

T/F
Fermentation contains Krebs cycle but not an ETC?

Back 56

F
it doesnt use either!

Front 57

How many net ATP are made during Glycolysis?
And is that the same in all forms of fermentation and cellular respiration?

Back 57

2 NET ATP
YES!

Front 58

In fermentation what is oxidized/ reduced?

Back 58

Oxidized: (lost e-) Glucose
Reduced: (gained e-) Pyruvic Acid
Happens from the giving off of H+ from NAD

Front 59

wer does fermentation release energy from?

Back 59

sugars or other organic molecules

Front 60

Is fermentation anaerobic or aerobic?

Back 60

it Does not require oxygen but can occur in its presence

Front 61

If yeast is in an aerobic environment what does it produce? anaerobic?

Back 61

aerobic: CO2
anaerobic: alcohol

Front 62

What is the final electron acceptor in fermentation?

Back 62

it is ORGANIC!
ex: sulfate, nitrate

Front 63

why does fermentation produce less ATP than cellular respiration?

Back 63

becase it doesn't get the 2 extra ATP from the Krebs cycle, nor does i get the multiple extra from the ETC

Front 64

What is oxidized/reduced in lactic acid fermentation?

Back 64

Lactic acid: reduced
NADH: oxidized

Front 65

Probiotics are what?

Back 65

dried bacteria, usually lactobacillus

Front 66

what accepts the H+ from NADH and is then changed to Ethanol

Back 66

Acetaldehyde

Front 67

Ethanol is reduced in alcohol fermentation? T/F

Back 67

True

Front 68

What are the 5 common end products of fermentation?

Back 68

1. Lactic Acid- Streptococcus, Lactobacillus
2. Alcohol: ethanol, CO2
3. Propionic Acid and CO2- Propionibacterium
4. Acetone and Isopropyl Alcohol: Clostridium
5. Ethanol and Lactic Acid, Acetic acid and Succinic acid: E. Coli

Front 69

What are commercial product for each of the 5 common end products of fermentation?

Back 69

1. Lactic Acid: yogurt
2. Alcohol: wine and beer
3. Propionic Acid + CO2: Swiss cheese
4. Acetone and Isopropyl Alc: Rubbing alcohol
5. Ethanol +lactic acid, Acetic acid, Succinic Acid: E. coli

Front 70

which form does Aerobic respiration use to generate ATP?
anaerobic?
Fermentation?

Back 70

substrate-level and oxidative
-anaerobic: substrate-level adn oxidation
-fermentation: substrate-level

Front 71

how many ATP are generated in each:
aerobic, anaerobic, and fermentation?

Back 71

aerobic: 36 (eu) 38 (pro)
anaerobic: btw (2-38)
fermentation: 2

Front 72

Lipids are composed of?

Back 72

glycerol and fatty acid(s)

Front 73

what does glycerol convert to?

Back 73

glycerol converts to dihydroxyacetone phosphate

Front 74

What does the dihydroxyacetone feed into?

Back 74

glycolysis

Front 75

Fatty acids convert to what?

Back 75

Acetyl CoA which feeds into Krebs

Front 76

what happens to Amino acids in Protein catabolism?

Back 76

they must be deaminated (amine group removed)

Front 77

what happens to the remainder of the amino acid after it has been deaminated?

Back 77

its converted to pyruvate, acetyl CoA, or feeds into Krebs cycle directly

Front 78

Transition step links glycolysis to what?

Back 78

Krebs Cycle

Front 79

During the transition step btw glycolysis and Krebs what happens to the pyruvic acid?

Back 79

it is oxidized and decarboxylated (COOH is split off as CO2)

Front 80

What does pyruvic acid turn into during the transition step btw glycolysis and krebs?

Back 80

2 Pyruvic acid per glucose results in 2 Acetyl CoA per glucose
*a 3 carbon molecule becomes a 2 carbon mol

Front 81

What are the products of the Krebs cycle?

Back 81

Acetyl CoA (2c)
Citric Acid (6c)
4 CO2
2 ATP
6 NADH
2 FADH2
Oxaloacetic acid (4 c)
** all #'s are for 2 spins of krebs cycle

Front 82

a 4c molecule (oxaloacetic acid) and a 2c (acetyl CoA) combine to for what?

Back 82

a 6c molecule- citric acid

Front 83

is FAD reduced or oxidized in Krebs cycle?

Back 83

reduced because it's gaining H+

Front 84

For every glucose molecule how many spins of the kreb cycle must you have?

Back 84

2!

Front 85

what are the other names of the Krebs Cycle?

Back 85

Tricarboxylic acid cycle (TCA)
Citric Acid Cycle

Front 86

the 2 ATP are made through what process?

Back 86

substrate level phosphorylation

Front 87

What form of energy is made first in substrate level phosphorylation in krebs cycle?

Back 87

GTP is made first, then broken down into GDP + Pi--> which creates energy

Front 88

What is the energy from the break down of GTP into GDP +Pi used for?

Back 88

Energy is used to put ADP + Pi to make ATP

Front 89

What does the break down of Succinyl CoA to CoA and Succinate do?

Back 89

creates energy to combine GDP + P

Front 90

What is the ETC?

Back 90

a series of carrier molecules that pass electrons given from NADH adn FADH2 via oxidation-reduction reactions

Front 91

where do the NADH and FADH2 come from in the ETC?

Back 91

theyre produced from glycolysis and Krebs cycle

Front 92

where is most of the cells ATP made?

Back 92

the ETC

Front 93

how many ATP are produced per NADH? FADH2?
why?

Back 93

NADH: 3
FADH2: 2
difference bc FADH2 feeds in farther down the chain which is why you get less ATP production

Front 94

what is the importance of the ETC?

Back 94

- it is a series of oxidation/reduction steps
-NADH adn FADH2: feed in a different locations (produce diff amounts of ATP)
-Final electron acceptor is OXYGEN

Front 95

what is the final electron acceptor in the ETC?

Back 95

oxygen
-aerobic respiration only
-when it accepts the electrons, the combination with the H+ creates H2O.

Front 96

Every glucose produces 36-38 molecules of ATP

Back 96

most come from ETC
2 from krebs
2 from glycolysis

Front 97

in chemiosmotic generation of ATP, for every NADH 6 H+ (protons) go through the ATP synthase pump what does that yield?

Back 97

it yields 3 ATP

Front 98

what is oxidative phosphorylation?

Back 98

ETC coupled with ATP generation

Front 99

photophosphorylation?

Back 99

when sunlight hits clorophyl. it hits electrons and passes through a chain similar to the ETC

Front 100

is oxygen the final electron receptor in anaerobic respiration?

Back 100

no, usually nitrate or sulfate

Front 101

in cellular respiration, glucose and oxygen combine with ADP +P to make what?

Back 101

carbon and water dioxide, and ATP

Front 102

can bacteria anaerobically respire?

Back 102

some!

Front 103

T/F ATP yield is always lower in anaerobic respiration than it is in aerobic respiration

Back 103

TRUE

Front 104

Does fermentation involve the Krebs Cycle?

Back 104

No, it also does not involve the ETC in glycolysis

Front 105

how many net ATP are produced form fermentation?

Back 105

2!

Front 106

In fermentation is glucose reduced or oxidized?

Back 106

it is oxidized, oxygen gives up its electrons to pyruvate. (which then oxidates pyruvate)

Front 107

T/F Pyruvic Acid is reduced in Fermentation?

Back 107

TRUE! it gains electrons through the H+ given off from NAD-

Front 108

HAVE YOU LOOKED UP FERMENTATION/ KREBS CYCLE/GLYCOLYSIS DIAGRAMS IN THE BOOK?

Back 108

IF NOT DO IT!

Front 109

Where does the energy released during fermentation come from?

Back 109

sugars or other organic molecules

Front 110

Does fermentation require oxygen?

Back 110

no, but it CAN occur in its presence

Front 111

What is produced from yeast during fermentation in both an anaerobic and aerobic environment?

Back 111

anaerobic: alcohol
aerobic: CO2

Front 112

How do the final electron acceptors differ in Krebs Cycle and fermentation?

Back 112

in fermentation: its an organic molecule (sulfate, nitrate)
in krebs: always OXYGEN

Front 113

Which process produces more ATP?

Back 113

Cellular respiration: bc of ETC
fermentation: only produces 2

Front 114

HAVE YOU LOOKED UP LATIC ACID FERMENTATION AND ALCOHOL FERMENTATION DIAGRAMS IN BOOK?

Back 114

GO DO IT NOW!

Front 115

in lactic acid fermentation what is reduced? oxidized?

Back 115

lactic acid (reduced)

Oxidized:
2 NADH + 2H --> 2 NAD+

Front 116

what is the name of the "dried bacteria" that is formed during lactic acid fermentation?

Back 116

probiotics
usually lactobacillus
(Activia yogurt)

Front 117

What is the beginning of the Alochol fermentation process?

Back 117

2 NADH (made from glycolysis) enter and are oxidized to form NAD+

Front 118

what accepts the H+ that were removed from the NADH to form alcohol?

Back 118

acetaldehyde

Front 119

what is reduced in alcohol fermentation?

Back 119

ethanol

Front 120

what are the common end products for fermentation?

Back 120

1. Lactic Acid: streptococcus, Lactobacillus (yogurt)
2. Alcohol: Ethanol + CO2 (wine/beer)
3. Propionic acid + CO2: propionibacterium (swiss cheese)
4. Acetone adn Isopropyl alc: Clostridium (rubbing alcohol)
5. ethanol +lactic acid, acetic acid, succinic acid: E.coli: micro test

Front 121

what are the components of household rubbing alcohol?

Back 121

clostridium
(acetone and isopropyl alcohol)

Front 122

HAVE YOU LOOKED UP LATIC ACID FERMENTATION AND ALCOHOL FERMENTATION DIAGRAMS IN BOOK?

Back 122

GO DO IT NOW!

Front 123

in lactic acid fermentation what is reduced? oxidized?

Back 123

lactic acid (reduced)

Oxidized:
2 NADH + 2H --> 2 NAD+

Front 124

What is the form of ATP generation used in aerobic respiration?
how many ATP are made in this type of resp?

Back 124

substrate- level and oxidative phosphorylation

euk: 36
pro: 38

Front 125

what is the name of the "dried bacteria" that is formed during lactic acid fermentation?

Back 125

probiotics
usually lactobacillus
(Activia yogurt)

Front 126

in anaerobic respiration what form of ATP generation is used?
how many ATP are generated?

Back 126

substrate- level and oxidative phosphorylation

variable ATP (2-38)

Front 127

What is the beginning of the Alochol fermentation process?

Back 127

2 NADH (made from glycolysis) enter and are oxidized to form NAD+

Front 128

what accepts the H+ that were removed from the NADH to form alcohol?

Back 128

acetaldehyde

Front 129

what is reduced in alcohol fermentation?

Back 129

ethanol

Front 130

what are the common end products for fermentation?

Back 130

1. Lactic Acid: streptococcus, Lactobacillus (yogurt)
2. Alcohol: Ethanol + CO2 (wine/beer)
3. Propionic acid + CO2: propionibacterium (swiss cheese)
4. Acetone adn Isopropyl alc: Clostridium (rubbing alcohol)
5. ethanol +lactic acid, acetic acid, succinic acid: E.coli: micro test

Front 131

what is the components of household rubbing alcohol?

Back 131

clostridium
(acetone and isopropyl alcohol)

Front 132

What is the form of ATP generation used in aerobic respiration?
how many ATP are made in this type of resp?

Back 132

substrate- level and oxidative phosphorylation

euk: 36
pro: 38

Front 133

in anaerobic respiration what form of ATP generation is used?
how many ATP are generated?

Back 133

substrate- level and oxidative phosphorylation

variable ATP (2-38)

Front 134

What form of ATP generation is used in fermentation? how many ATP are generated?

Back 134

substrate-level
2 ATP generated

Front 135

in Lipid and protein catabolism what is converted?

Back 135

glucose

Front 136

HAVE YOU LOOKED AT THE LIPID AND PROTEIN DIAGRAM IN THE BOOK??

Back 136

DO IT NOW!

Front 137

what are lipids composed of?

Back 137

glycerol and fatty acids

Front 138

What does glycerol convert to in Lipid Catabolism inorder to feed into glycolysis?

Back 138

dihydroxyacetone phosphate

Front 139

In Lipid catabolism what is converted into Acetyl CoA which feeds into the Krebs Cycle

Back 139

fatty acids

Front 140

Proteins are chains of amino acids

Back 140

LOOK AT STRUCTURE OF AMINO ACID IN NOTES RIGHT NOW!

Front 141

amino acids must be deaminated during what process? (amine group removed)

Back 141

protein catabolism

Front 142

what happens to the remainder of the molecule that is not the amino acid in protein catabolism?

Back 142

converted to: pyruvate, acetyl CoA OR
feeds directly into Krebs

Front 143

What is the goal of metabolism?

Back 143

so organisms can oxidize molecules to produce energy through aerobic respiration, anaerobic respiration and/or fermentation

Front 144

T/F some energy is lost as heat during metabolism process?

Back 144

TRUE

Front 145

concluding that some energy from metabolic process is lost as heat what is the remaining energy used for?

Back 145

1. active transport
2. locomotion
3. make cellular moleucles

Front 146

INTEGRATION OF METABOLISM DIAGRAM

Back 146

LOOK AT IT

Front 147

what is microbial growth?

Back 147

growth of bacterial populations

Front 148

T/F microbial growth refers to the number of cells?

Back 148

true

Front 149

how do bacteria reproduce

Back 149

binary fission

Front 150

generation time?

Back 150

the time required for a cell to divide and its population to therefore double

can vary among diff organisms

Front 151

LOOK UP:::: PHASES: LAG, LOG, STATIONARY, DEATH

Back 151

REMEMBER:
A COMES B4 O IN ALPHABET (LAG B4 LOG)

Front 152

chemical requirements for growth?
new cig

Back 152

1. carbon- CO2 OR organic (sugar)
2. nitrogen- needed for protein synthesis (amine gp of amino acid)
3. inorgainc ions (minerals)- cofactors for enzymes
4. growth factors- certain amino acids and coenzymes (vitamins)
5. water- needed for some enzymatic reactions
6. energy source- light or chemicals

Front 153

Which is more efficient in producing amino acids and vitamins? e. coli or humans?

Back 153

E. Coli can make all of its own amino acid and vitamins while humans can only make about 1/2 of amino acids

Front 154

what type of organisms use an energy source for food? light? chemicals?

Back 154

light: phototroph
chemicals: chemotroph

Front 155

which organism uses a carbons source for food? CO2? Organic carbon?

Back 155

CO2: autotroph
Organic carbon: hetertroph

Front 156

T/F microbial growth refers to the number of cells?

Back 156

true

Front 157

what type of organism uses both light for energy and CO2 for carbon (self feeders)

Back 157

photoautotrophs

Front 158

how do bacteria reproduce

Back 158

binary fission

Front 159

in photosynthesis: hydogens from water reduce/oxidize carbon dioxide to make food?

Back 159

reduce

Front 160

generation time?

Back 160

the time required for a cell to divide and its population to therefore double

can vary among diff organisms

Front 161

LOOK UP:::: PHASES: LAG, LOG, STATIONARY, DEATH

Back 161

REMEMBER:
A COMES B4 O IN ALPHABET (LAG B4 LOG)

Front 162

chemical requirements for growth?

Back 162

1. carbon- CO2 OR organic (sugar)
2. nitrogen- needed for protein synthesis (amine gp of amino acid)
3. inorgainc ions (minerals)- cofactors for enzymes
4. growth factors- certain amino acids and coenzymes (vitamins)
5. water- needed for some enzymatic reactions
6. energy source- light or chemicals

Front 163

Which is more efficient in producing amino acids and vitamins? e. coli or humans?

Back 163

E. Coli can make all of its own amino acid and vitamins while humans can only make about 1/2 of amino acids

Front 164

what type of organisms use an energy source for food? light? chemicals?

Back 164

light: phototroph
chemicals: chemotroph

Front 165

which organism uses a carbons source for food? CO2? Organic carbon?

Back 165

CO2: autotroph
Organic carbon: hetertroph

Front 166

what type of organism uses both light for energy and CO2 for carbon (self feeders)

Back 166

photoautotrophs

Front 167

in photosynthesis: hydogens from water reduce/oxidize carbon dioxide to make food?

Back 167

reduce

Front 168

what is the formula for photosynthesis in green and purple sulfur?

Back 168

CO2 + 2H2S --(light)--> (CH2O)n + H2O +2S

Front 169

what is the difference btw green and purple sulfur photosyntheis and reg photosynthesis?

Back 169

green/purple sulfur has an organic compound in the result (CH2O)
WHICH MEANS NO OXYGEN is produced -- but SULFUR is

Front 170

photoheterotrophs use which two sources to obtain energy?

Back 170

light and organic carbon sources

Front 171

Can photoheterotrophs convert CO2 to sugars?

Back 171

NO! they must have an organic food source.
ex; green nonsulfur bacteria and purple nonsulfur bacteria

Front 172

Do photoheterorophs use light for food?

Back 172

no they use it for energy, but need to be provided with outside sources of food

Front 173

The light that is used for energy goes through what process?

Back 173

the photosynsitive pigments attract the light and excite the electrons to go through the ETC

Front 174

What source do Chemoatotrophs use for energy?

Back 174

inorganic compounds= energy and CO2 as a carbon source

Front 175

What is a function of chemoautotrophs/

Back 175

they can leach minerals from an ore: extraction of copper from copper ore.

Front 176

T/F ammonia is a common energy source in chemoautotrophs?

Back 176

t/f some use it.
allows them to return nitrogen back to the environment.
- found in soil, where they encounter nitrogen as waste product of animals

Front 177

Chemoheterotrophs are what form of organisms?

Back 177

WE ARE CHEMOHETEROTROPHS!

Front 178

what type of nutritional classification uses organic sources for energy and carbon?

Back 178

chemoheerotrophs
(glucose may be used for both sources!)

Front 179

can chemoheterotrophs use light and/ or CO2 for energy?

Back 179

NO! they must be fed!

Front 180

is oxygen a requirement for all cell growth?

Back 180

no, anaerobes do not need oxygen to grow

Front 181

What is a free radical of oxygen and who produces it?

Back 181

free radical: highly reactive particle with an unpaire electron:
superoxide O2-.
(organisms who go through aerobic respiration produce superoxide)

Front 182

why is superoxide harmful to cells?

Back 182

steals electrons away from neighboring molecules-- which will in turn become a free radical itself

Front 183

aerobic cells neutralize superoxide by which enzymes?

Back 183

superoxide dismutase and catalase enzymes

Front 184

LOOK AT REACTION OF NEUTRALIZING SUPEROXIDE

Back 184

the very end components are water and oxygen

Front 185

can anaerobes experience free radicals of oxygen?

Back 185

no they cannot make catalase or superoxide dismutase
w

Front 186

why do strict anaerboes die in the presence of oxygen?

Back 186

they lack superoxide dismutase and usually catalas
(ex: clostridium)

Front 187

how is superoxide produced?

Back 187

if the O2 accepts 1 electron at the end of the ETC

Front 188

why are hydrogen peroxide and superoxide bad for the cell?

Back 188

they attack unsaturated fatty acids in membrane lipids and can cause the membrane to lyse

Front 189

what is prevented through the control of microbial growth?

Back 189

1. contamination
2. spoilage
3. transmission of infection and disease

Front 190

Does controlling microbial growth always mean killiing the bacteria?

Back 190

NO! they can also be used to stop the growth: bacteriastatic

Front 191

what is sterilization?

Back 191

is killing or removal of all life forms in a given area.
ZERO bacteria

Front 192

UV light is a form of which form of which type of radiation?

Back 192

nonionizing radiation

Front 193

what does UV light effect in the cell?

Back 193

causes mutations in DNA-
pyrimidines (thymine or cytosine) bind together instead of with with the cells across on the other strand

Front 194

what are two examples of pyrimidines?

Back 194

thymine or cytosine
*hint: all have "y's" in the name!

Front 195

do you need to have direct exposure to UV rays for them to be effective?

Back 195

yes!

Front 196

ionizing radiation consists of what forms of radiation?

Back 196

gamma rays, x-rays, and electrons beams

Front 197

what do ionizing radiation beams ionize?

Back 197

water inside the cell to form a highly reactive free radical

Front 198

what are hydroxyl radicals?

Back 198

they steal electrons away form cellular components especially DNA- causes mutations/possible death
(cancer)

Front 199

What are the physical methods of controlling microbial growth?
ch ford

Back 199

heat
filrtration
cold
desiccation
osmotic pressure
radiation

Front 200

What is the most effective form of heat for controlling microbial growth?

Back 200

autoclaving- bc it also ensures death of endospores, unlike boiling, pasteurization or dry heat

Front 201

what are the 3 forms of dry heat?

Back 201

direct flaming (loops in lab)
incineration (animals in lab)
[both ^ burn to ashes]
hot- air sterilization (old labs- in oven)

Front 202

Is pasteurization considered sterilization?

Back 202

no, only stopped growing not killed

Front 203

are all 3 forms of Dry heat sterilization?

Back 203

yes! and are all very effective

Front 204

why is heat an effective method of controlling microbial growth?

Back 204

because heat denatures proteins which in turn denatures enzymes. w/o enzymes the cell cannot grow and function effectively

Front 205

Why does being cold effect the growth of bacteria?

Back 205

it slows down molecular mvmt, which leads to less enzymatic activity= less growth.
also there can be possible changes in proteins

Front 206

deep freezing works in controlling growth bc?

Back 206

there is lots of H2O in ells which create ice crystals w/ jagged edges when frozen. these crystals can disrupt and injure the cell membrane

Front 207

what is the main focus of desiccation?

Back 207

removal of water.
which disrupts the metabolism
bacteriostatic

Front 208

why does desiccation work for controlling growth?

Back 208

bc many metabolic reactions require H2O and w/o it the reactions cannot happen

Front 209

osmotic pressure is revolved around what ideal?

Back 209

cell wall theory.
plasmolysis occurs- cell shrinks

Front 210

what is osmotic pressure most commonly used in

Back 210

salt cured or sugar cured food. results in loss of water from cells.

Front 211

which is better suited for inhibiting the growth of living organisms? antiseptics or disinfectants

Back 211

antiseptic

a disinfectant cleans non living surfaces

Front 212

how do chemical agents work?

Back 212

destroying the cell membrane and/or denaturing proteins

Front 213

concentration, time, temperature, and the surrounding environment are all variables for what?

Back 213

they are all things to consider in chemical controls of microbial growth