Med Micro Exam 2

Question 1

What are some growth requirements for microbes?

Answer 1

-electrons sources(organic and inorganic compounds)
-carbon sources(autotrophs and heterotrophs)
-energy sources [light(phototrophs) and chemical (chemotrophs)]

Question 2

What is microbial growth?

Answer 2

-increase in population of microbes
-due to reproduction of individual microbes

Question 3

What are results of microbial growth?

Answer 3

-colonies
-biofilms

Question 4

What elements do most nutrients need to reproduce?

Answer 4

-carbon
-oxygen
-nitrogen
-hydrogen

Question 5

Oxygen and obligate anaerobes relationship:

Answer 5

-oxygen is deadly for obligate anaerobes
-toxic forms of oxygen are highly reactive and excellent oxidizing agents
-resulting oxidation causes irrepairable damage to cells

Question 6

What are the 4 toxic forms of oxygen?

Answer 6

-Singlet O2
-superoxide radicals
-peroxide anion
-hydroxyl radical

Question 7

Obligate aerobes

Answer 7

only live in oxygen

Question 8

Obligate anaerobes

Answer 8

can’t live in oxygen

Question 9

Facultative anaerobes

Answer 9

prefer to live in oxygen but can live without it

Question 10

Aerotolerant anaerobes

Answer 10

they don’t give a shit they live all over in both

Question 11

Nitrogen requirements:

Answer 11

-insufficent nitrogen ends anabolism to make amino acids and nucleotides
-nitrogen fixation by certain bacteria is essential to life

Question 12

Chemical requirements

Answer 12

-phosphorus
-sulfur

Question 13

trace elements:

Answer 13

only required in small amounts

Question 14

Growth factors:

Answer 14

necessary organic chemicals that can’t be synthesized by certain organisms.

Question 15

Temperature:

Answer 15

-organisms have an optimal temperature due to protein structure and lipid membranes of cells and organelles

Question 16

pH ranges:

Answer 16

-organisms sensitive to changes in acidity
-H ions interfere with H bonding

Question 17

Neutrophiles:

Answer 17

grows best in narrow range around neutral pH

Question 18

Acidophiles:

Answer 18

grows best in acidic habitats

Question 19

Obligate acidophiles:

Answer 19

-won’t grow if pH is over 7

Question 20

Acid-tolerant organisms:

Answer 20

can tolerate low pH

Question 21

Alkalinophiles:

Answer 21

live in alkaline soils and waters

Question 22

What do microbes require?

Answer 22

they require water to dissolve enzymes and nutrients

Question 23

crenation:

Answer 23

disappearance of cytoplasm and death of cell

Question 24

osmotic pressure

Answer 24

pressure exerted by a cell membrane by a solution containing solutes that can’t freely cross the membrane

Question 25

hydrostatic pressure

Answer 25

water exerts pressure in proportion to its depth

Question 26

barophiles

Answer 26

live under extreme pressure

Question 27

antagonist relationship

Answer 27

bacteriophage and bacteria

Question 28

synergistic relationship

Answer 28

when organisms team up to create a disease that one couldn't do on its own -biofilm

Question 29

biofilms

Answer 29

-complex relationships among numerous microorganisms -many microorganisms are more harmful as part of biofilm

Question 30

quorum sensing:

Answer 30

-microbes excrete a compound -when the compound is high in density, the other cells know other similar microbes are nearby

Question 31

biofilm formation

Answer 31

1. free living bacteria in environment 2. settlement and attachment 3. formation of EPS 4. cell communication and division of labor 5. new cells arrive , water channels form in biofilm

Question 32

defined media

Answer 32

concentrations of chemicals are known

Question 33

complex media

Answer 33

chemical composition are unknown -nutrients are derived from yeast, soy, beef -supports growth of wide variety -good when nutritional needs of microbe is unknown

Question 34

what does an enzyme bind to?

Answer 34

substrate, very specific

Question 35

genotype:

Answer 35

set of genes in the genome (y, Y)

Question 36

phenotype:

Answer 36

physical features of the organism (yellow)

Question 37

What is the result of transcription?

Answer 37

mRNA

Question 38

Central Dogma

Answer 38

theory stating that genetic information flows only in one direction

Question 39

3 stages of transcription

Answer 39

1. initiation 2. elongation 3. termination

Question 40

Operon

Answer 40

promotor, operator and a series of genes

Question 41

Operator

Answer 41

regulatory element

Question 42

mutation:

Answer 42

change in nucleotide sequence of genome it is rare and hereditable

Question 43

point mutation:

Answer 43

one base pair is affected

Question 44

gross mutations

Answer 44

includes inversions, duplications, transpositions

Question 45

ionizing radiation

Answer 45

energize electrons to leave atoms

Question 46

nonionizing radiation

Answer 46

does not energize electrons