Classification and Structure of Prokaryotic Cells

Question 1

Prokaryotes (in general)

Answer 1

they do not contain membrane-bound organelles

they organize their genetic material in a single circular molecule of DNA concentrated in the nucleoid region

Question 2

what are the 3 overarching domains of life? how many do prokaryotes account for?

Answer 2

Archaea, bacteria, and eukarya

Question 3

archaea

Answer 3

• these are often extremophiles, living in harsh environments (high temps, high salinity, no light)
• they often use alternative sources of energy, like chemosynthesis

Question 4

what similarities do they share with _____ & _____?

Answer 4

• eukaryotes: start translation with methionine, similar RNA polymerases, histones
• prokaryotes: single circular chromosome, divide by binary fission or budding

Question 5

Bacteria

Answer 5

they have many similar structures to eukaryotes and have complex relationships with humans, including symbiosis and pathogenesis

Question 6

eukarya

Answer 6

this is the only non-prokaryotic domain

Question 7

Bacteria can be classified by what shapes?

Answer 7

• cocci: spherical
• bacilli: rod-shaped
• spirilli: spiral-shaped

Question 8

bacteria can be classified based on metabolic processes, what are they?

Answer 8

• obligate aerobes
• obligate anaerobes
• facultative anaerobes
• aerotolerant anaerobes

Question 9

obligate aerobes

Answer 9

require oxygen for metabolism

Question 10

obligate anaerobes

Answer 10

cannot survive in oxygen-containing environments and can only carry out anaerobic metabolism

Question 11

facultative anaerobes

Answer 11

can survive in environments with or without oxygen and will toggle metabolic processos based on the environment

Question 12

aerotolerant anaerobes

Answer 12

cannot use oxygen for metabolism, but can survive in an oxygen-containing environment

Question 13

the bacterial envelope

Answer 13

the cell wall and cell membrane form this; together, they control the movement of solutes into and out of the cell

Question 14

staining bacteria to classify them

Answer 14

bacteria can be classified by the color their cell walls turn during Gram staining with a crystal violet stain, followed by a counterstain with safranin.
-Gram-positive bacteria turn purple
Gram-negative bacteria turn pink-red

Question 15

Gram-positive bacteria

Answer 15

they have a thick cell wall composed of peptidoglycan and lipoteichoic acid

Question 16

Gram-negative bacteria

Answer 16

they have a thin cell wall composed of peptidoglycan and an outer membrane containing phospholipids and lipopolysaccharides

Question 17

bacteria and flagella

Answer 17

-they ahve one, two, or many flagella that generate propulsion to move the bacterium toward food or away from immune cells.

Question 18

chemotaxis

Answer 18

moving in response to chemical stimuli

Question 19

how do prokaryotes carry out the ETC

Answer 19

they use the cell membrane

Question 20

Prokaryote and Eukaryote ribosome sizes

Answer 20

• prok: 30S & 50S

- euk: 40S & 60S