Chapter 4 (Book) Bacterial Growth

Question 1

essential nutrients

Answer 1

compounds a microbe cant make, but must gather from the environment to grow and divide

Question 2

macronutrients

Answer 2

nutrients needed in large quantities

carbon, nitrogen, phosphorous, hydrogen, oxygen, sulfur

form carbohydrates, lipids, nucleic acids, proteins

Question 3

cofactors

Answer 3

Mg

Fe

K

Question 4

micronutrients (components of enzymes)

Answer 4

cobalt

copper

zinc

manganese

nickel

Question 5

defined mineral medium

Answer 5

contains only the nutrients a microbe needs to grow

Question 6

what percent of microbes are unculturable

Answer 6

99.9%

Question 7

microbes build biomass through _______ or _______

Answer 7

autotrophy, heterotrophy

Question 8

heterotrophy

Answer 8

rely on other organisms to form the organic compounds they use as carbon sources

Question 9

autotrophy

Answer 9

fix CO2 into complex organic molecules

Question 10

2 classifications of autotrophs

Answer 10

photoautotroph

chemoautotrophs

Question 11

photoautotroph

Answer 11

use light for photosynthesis (energy)

Question 12

chemoautotrophs

Answer 12

gain energy by oxidizing inorganic substances like iron/ ammonia or oxidizing organic compounds

chemolithotrophs

organotrophs

Question 13

membrane potential

Answer 13

energy stores by an electrical potential across the membrane

generated when protons are pumped outside of the cell (inside negative)

Question 14

electrochemical potential

Answer 14

ion gradient + charge difference

aka proton motive force

Question 15

what can the proton motive force be used for

Answer 15

move nutrients into cell via transporters

drive motors that rotate flagella

drive synthesis of ATP by ATP synthase

Question 16

the nitrogen cycle depends on _______ and _______

Answer 16

bacteria, archaea

Question 17

N2 gas makes up how much of Earth’s atmosphere

Answer 17

79%

Question 18

for nitrogen to be used for growth, it must be ______, or converted into ammonium ions

Answer 18

fixed

Question 19

nitrogen fixing bacteria

Answer 19

free-living in soil or water

or form symbiotic associations with plants

Question 20

symbiont

Answer 20

an organism that lives in intimate association with another organism

Question 21

mixotrophic

Answer 21

able to use photosynthesis or heterotrophic respiration depending on environmental conditions

Question 22

3 ways selective permeability is achieved

Answer 22

substrate-specific carrier proteins in the memb

nutrient-binding proteins in periplasmic space

membrane-spanning protein channels/pores

Question 23

facilitated diffusion

Answer 23

from high concentration to low concentration

ex. aquaporin, GlpF glycerol transporter in E.coli

Question 24

GlpF

Answer 24

2 conformations – one exposes glycerol binding site to environment, other releases glycerol into cytoplasm

facilitated diffusion, so passive and high [ ] to low [ ]

Question 25

coupled transport

Answer 25

using the energy from moving an ion down its conc gradient to move a molecule against its conc gradient

symport - same direction

antiport - opposite directions

Question 26

LacY symporter in E. coli

Answer 26

moves lactose inside cell

powered by proton also moving in the cell

Question 27

Na/H antiporter

Answer 27

moves Na+ out and H+ in

Question 28

ABC transporters are powered by ___

Answer 28

ATP

ATP-binding cassete transporters

Question 29

ABC transport

Answer 29

substrate-binding protein snags a solute (periplasm of gram neg, outside of gram pos)

solute attaches to ABC transporter which hydrolyzes ATP –> ADP

conformational change allows solute to enter cell

Question 30

siderophores

Answer 30

secreted molecules with an affinity for iron

attached iron sent into cell by ABC or a transporter

Question 31

group translocation

Answer 31

alters substrate during transport by attaching a different group to it so it is moving down a [ ] gradient

ex. phosphotransferase system (PTS)

Question 32

phosphotransferase system (PTS)

Answer 32

a group translocation system in bacteria

attach phosphate to sugars during transport

Question 33

can an ABC transporter be used as a multidrug efflux pump?

Answer 33

yes