Exam 2 Flashcards Preview

Microbiology > Exam 2 > Flashcards

Flashcards in Exam 2 Deck (74):
1

Carbohydrate functions

E storage, receptors, food, structure in plants, fungal cell walls, exoskeletons of insects

2

Lipids functions

E storage, membrane structure, insulation, hormones, and pigments

3

Nucleic acid functions

Storage and transfer of genetic info

4

Protein functions

Enzymes, structure, receptors, transport, structure in cytoskeleton and ECM

5

Monosaccharides

Simple sugars - building blocks of complex carbs

6

Disaccharides

2 monosaccharides, covalently bonded-glycosidic bond

7

Polysaccharides (glycans)

Large polymers of monosaccharides

8

Fatty acids

Lipids that contain long-chain hydrocarbons with -COOH group

9

Triglycerides

3 fatty acids and a glycerol (E storage)

10

Phospholipids

Phosphate group and glycerol and 2 fatty acid chains

11

Amino acids

H + carboxyl group + amino group + variable side chain (chemical/peptide bond)

12

Metabolism

Sum of all reactions in a cell - buildup and breakdown of nutrients within a cell

13

Catabolism

Break down, release E

14

Anabolism

Build up, use E

15

Chemotrophs

Energy source = chemicals
Chemoautotrophs have inorganic carbon source (H-, S-, Fe-, N-, and CO-oxidizing bacteria)
Chemoheterotrophs have organic sources of carbon (all animals, most fungi, protozoa, and bacteria)

16

Phototrophs

Energy source = light
Photoautotrophs have inorganic sources of carbon (all plants, algae, cyanobacteria, green and purple S bacteria)
Photoheterotrophs have organic sources of carbon (green and purple non-S bacteria and heliobacteria)

17

Oxidation

Loss of electrons

18

Reduction

Gain of electrons

19

Glycolysis produces? occurs in?

2 ATP, 2 NADH, 2 pyruvate; cytoplasm of bacteria, eukaryotes, and most archaea

20

Prepatory stage of glycolysis

Glucose phosphorylated and 2 ATP used

21

Energy-conservation stage of glycolysis produces

4 ATP, 2 NADH, 2 pyruvate

22

Process of enzymatic activity

1.) Substrate enters active site
2.) Enzyme/substrate complex forms (enzyme changes shape slightly)
3.) Substrate converted to products
4.) Products leave active site (enzyme returns to original conformation)

23

Pyruvate oxidation

Makes 2 molecules of acetyl coA; occurs in mitochondrial matrix (eukaryotes) and cytoplasm (prokaryotes)

24

Krebs Cycle

Transfers remaining electrons from acetyl groups to electron carrier molecules (occurs in same location as pyruvate oxidation); produces NADH, FADH2, ATP, releases CO2 as waste

25

Electron transport system

Series of membrane-associated protein complexes and accessory electron carriers and chemical reactions that move NADH and FADH2 down the line

26

Final electron acceptor depends on type of organism and availability of molecules

Oxygen (aerobic respiration) - produces water
Nitrate (NO3-) and nitrite (NO2-) (anaerobic respiration) - produces N2
Sulfate (SO42-) (anaerobic respiration) - produces H2S
CO2 and carbonate (CO3) (anaerobic respiration) - produces CH4

27

Theoretical yields of ATP

Glycolysis: 8
Transition: 6
Krebs: 24
Total = 38 ATP
Anaerobic lower yields (5-36)

28

Lactic acid fermentation

Produce lactic acid from pyruvate (yogurt, pickling, vaginal, g+ bacteria)

29

Alcohol fermentation

Produce ethanol from pyruvate (alcohol, breads, yeast)

30

Lipid catabolism

Breaks down triglycerides for long-term energy storage

31

Light-dependent reactions

Conversion of light energy into chemical energy

32

Carbon fixation (light-independent) reactions

ATP and NADPH used to reduce CO2 to sugar in Calvin-Benson cycle

33

Oxygenic photosynthesis

6 CO2 + 12 H2O + light >>>> C6H12O6 + 6 H20 + 6 O2

34

Anoxygenic photosynthesis

6 CO2 + 12 H2S + light >>>>> C6H12O6 + 6 H2O + 12 S

35

Carbon cycle

Constant exchange of CO2 between heterotrophs (produce CO2) and autotrophs (use CO2)

36

Nitrogen cycle

Prokaryotes transform N between various forms for their own needs, benefitting other organisms indirectly (getting N to living organisms is difficult)

37

Sulfur cycle

Several groups of microbes responsible for carrying out processes involved in S cycle

38

Bioremediation

Leverages microbial metabolism to remove pollutants from environment (humans introduced things like adhesives, dyes, flame retardants, lubricants, organic solvents, pesticides, and petroleum in environment in greater concentration than naturally occurs causing it to accumulate in food and water supply)

39

Binary fission

1. Cell grows and increases number of cell components
2. Replication of DNA starts at location on chromosome
3. Replication continues in opposite directions until terminus reached
4. center of cell constricts until 2 daughter cells formed
5. cytokinesis directed by protein FtsZ
6. FtsZ assembles into z ring and defines division plane between 2 daughter cells
7. Peptidoglycan cell wall development is activated - builds septum that divides 2 cells

40

Generation time for eukaryotes

Time between same points of life cycle in 2 successive generations

41

Generation time for prokaryotes

Time it takes for population to double through one round of binary fission (doubling time)

42

Growth curve

Lag - no increase in number of living cells
Log - exponential increase in living bacterial cells (most sensitive to antibiotics here)
Stationary - nutrient levels too low to sustain growth/waste products build; number of cells dividing = number of cells dying
Death - accumulate toxic waste; nutrients used up, viable cells decrease; endospores form; some persisters (slow metabolic rate)

43

Simplest way to count that transfers a known volume of culture to a calibrated slide with counting grids and count cells under microscope

Direct microscope cell count

44

Advantages and disadvantages of direct microscope cell count

A: easy to use, fast, cheap
D: doesn't work well with dilute samples and unable to distinguish between living or dead cells or debris

45

Device detects and counts change in electrical resistance in saline solution as cells pass through

Electronic direct cell count

46

Advantages and disadvantages to electronic direct cell count

A: rapid and accurate with wide range of concentrations
D: cannot differentiate between living and dead cells

47

Method to inoculate plates that proceed as follows: bacteria mixed with agar, sample poured onto plate, swirled to mix, and incubate

Pour plate method

48

Method to inoculate plates that proceed as follows: sample poured on solid medium, spread sample evenly, and incubate

Spread plate method

49

Indirect cell count methods

Estimate based on cell presence or activity (turbidity, metabolic activity, and dry weight)

50

Highly structured communities that provide advantages to their constituent microorganism that have an increased resistance to antibiotics

Biofilms

51

Requires O2

Obligate aerobes

52

Prefers O2, but can grow without

Facultative anaerobes

53

Cannot have O2

Obligate anaerobes

54

Requires only a little O2

Aerotolerant anaerobes

55

With or without O2 (doesn't use O2 for E harvesting)

Microaerophiles

56

pH

Acidophile = <5.5
Neutrophile = 6.5-7.5
Alkaliphile = >8.5

57

Temperature

Mesophile = 20-45 C
Psychrotroph = 4-25 C
Thermophile = 50-80 C
Hyperthermo = 80-110 C

58

Withstand up to 10% salt concentration

Halotolerant

59

Require higher salt concentration

Halophile

60

Require atmospheric pressure

Barophiles

61

Complex polysaccharide used as a solidifier for culture media in Petri plates

Agar

62

Complex media

Extracts and digests of yeasts, meats, and plants

63

Selective media

Suppress unwanted and encourage desired microbes

64

Differential media

Allow distinguishing of colonies of different microbes on same plate

65

Enrichment media

Encourages growth of desired microbe by increasing small number of desired to detectable levels

66

Reducing media

Used for cultivation of anaerobic bacteria

67

Removal or killing of all vegetative cells, endospores, or viruses

Sterilization

68

Brief heating to reduce number of spoilage organisms, destroy pathogens from food, but doesn't mess with food quality

Pasteurization

69

Elimination of most or all pathogens (some viable may remain)

Disinfection (disinfectant on inanimate objects; antiseptic on living tissues)

70

Mechanical removal of microbes from a limited area

Degerming

71

Decrease microbial counts to levels that meet accepted health standards

Sanitation

72

Treatments that kill microbes

Biocide/germicide

73

Reduce pathogens to levels considered safe to handle

Decontamination

74

Process of delaying spoilage of foods and other perishable products

Preservation