Chapter 6

Question 1

Basic groups based on their carbon and energy sources

Answer 1

photoautotrophs
chemoautrotrophs
photoheterotrophs
chemoheterotrophs

Question 2

oxygen is essential for

Answer 2

obligate aerobes
- because it serves as the
final electron acceptor of electron transport chains, which produce
most of the ATP in these organisms.

Question 3

oxygen is a poison to

Answer 3

obligate anaerobe

Question 4

Able to detoxify peroxide anion O2 2-

Answer 4

catalase
- converts H2O2 to water and oxygen

peroxidase
- uses NADH as coenzyme

Question 5

Able to detoxify superoxide radical O2 -

Answer 5

superoxide dismutase

- have active sites with metal ions

Question 6

vitamins to protect against toxic oxygen products

Answer 6

Vitamin C and E

- give electrons to reduce toxic forms of oxygen

Question 7

some aerobic organisms
can maintain life via fermentation or anaerobic respiration,
though their metabolic efficiency is often reduced in the absence
of oxygen. Such organisms are called

Answer 7

facultative anaerobes

- E coli

Question 8

do not use aerobic metabolism, but
they tolerate oxygen by having some of the enzymes that detoxify
oxygen’s poisonous forms

Answer 8

aerotolerant anaerobes

- lactobacilli

Question 9

Requires oxygen lvl of 2% to 10%

Answer 9

microaerophiles

- ulcer causing pathogens like H pylori

Question 10

only at top of test tube

Answer 10

obligate aerobe

Question 11

only at bottom of test tube

Answer 11

obligate anaerobe

Question 12

disperse throughout the test tube but higher concentration at top

Answer 12

facultative anaerobe

Question 13

disperse throughout the test tube

Answer 13

aerotolerant anaerobe

Question 14

Occurs in nitrogen fixation

Answer 14

reducing nitrogen gas to ammonia

Question 15

necessary organic chemicals

Answer 15

growth factors

Question 16

require very small amounts of these elements

Answer 16

trace elements

Question 17

Important element for life

Answer 17

C
H
O
N

Question 18

lowest temperature at which an organism is able to conduct metabolism

Answer 18

minimum growth temperature

- may be able to survive below this temperature but will not grow/reproduce

Question 19

highest temperature at which an organism continues to metabolize

Answer 19

maximum growth temperature

Question 20

grow at temperatures below 15 degree C

Answer 20

Psychrophiles

Question 21

Categories of microbes based on temperature range growth

Answer 21

Psychrophiles

mesophiles
- 20 to 40

thermophiles
- above 45 degree C

hyperthermophiles
- above 80 or 100 degree C

Question 22

microbes that like the pH in the human body

Answer 22

neutrophiles

6.5 to 7.5 pH

Question 23

many fungi like this pH

Answer 23

acidophiles

Question 24

microbes that like the pH in the dirt

Answer 24

alkalinophiles

- vibrio cholera (water)

Question 25

diffusion of water across a membrane

Answer 25

osmosis

Question 26

define osmotic pressure

Answer 26

is the pressure exerted on a membrane by a
solution containing solutes (dissolved material) that cannot
freely cross the membrane. Osmotic pressure is related to the
concentration of dissolved molecules and ions in a solution.

Question 27

shriveling of its cytoplasm is called

Answer 27

crenation

= cell placed in salt water

Question 28

Organisms that live in the Great Salt Lakes

Answer 28

Obligate halophiles

- live under high osmotic pressure

Question 29

Organism that leave deep in water

Answer 29

live under high hydrostatic pressure

- are barophiles

Question 30

Biofilms form as a result of a process called

Answer 30

quorum sensing

- microorganisms respond to the density of nearby microorganism–> cells communicate with each other

Question 31

Steps in binarry fission

Answer 31

1 The cell replicates its chromosome (DNA molecule). The
duplicated chromosomes are attached to the cytoplasmic
membrane. (In eukaryotic cells, chromosomes are attached
to microtubules.)
2 The cell elongates and growth between attachment sites
pushes the chromosomes apart. (Eukaryotic cells segregate
their chromosomes by the process of mitosis, described in
Chapter 12.)
3 The cell forms a new cytoplasmic membrane and wall
(septum) across the midline.
4 When the septum is completed, the daughter cells may remain
attached as shown in the figure, or they may separate
completely. When the cells remain attached, further binary
fission in parallel planes produces a chain. When further
divisions are in different planes, the cells become a cluster
(as shown in the figure).
5 The process repeats.

Question 32

binary fission is able to grow in numbers by…

Answer 32

logarithmic growth or exponential growth

Question 33

Label and Draw a microbial growth curve

Answer 33

lag phase at beginning

log/exponential phase as # of cells go up

then stationary phase

finally the death/decline phase