Chapter 4 - Organelles, Cell Structure, Function

Question 1

Who proposed endosymbiotic theory?

Answer 1

Lynn Margulis

Question 2

average bacteria size

Answer 2

1-5 micrometers

Question 3

Most bacteria are in the range:
___-____ in diameter
- in length

Answer 3

0.2-2 micrometers; 2-8 micrometer

Question 4

bacillus

Answer 4

rod shapped

Question 5

coccus

Answer 5

spherical

Question 6

vibrio

Answer 6

comma

Question 7

spirrulum

Answer 7

rigid helix

Question 8

spirochetes

Answer 8

flexible

Question 9

diplo-

Answer 9

pairs

Question 10

clusters

Answer 10

staphylo-

Question 11

strepto-

Answer 11

chains

Question 12

cytoplasm

Answer 12

gel-like network

Question 13

cell membrane

Answer 13

encloses the cytoplasm; defines the existence of a cell

Question 14

nucleoid

Answer 14

non-membrane bound area of the cytoplasm that contains the chromosome in the form of looped coils

Question 15

cell wall

Answer 15

covers the cell membrane, prevents events osmotic lysis, confers shape & rigidity

Question 16

flagellum

Answer 16

external helical filament whose rotary motor propels the cell

Question 17

What are the functions of membrane proteins?

Answer 17

structural integrity, receptors, secretion of virulence factors and communication signals, ion transport, energy storage, uptake of molecules from outside the cell

Question 18

hopanoids

Answer 18

planar molecules that fill gaps between hydrocarbon chain

Question 19

simple diffusion

Answer 19

movement of a solute from an area of high [ ] to an area of low [ ]

Question 20

osmosis

Answer 20

water diffusion

Question 21

facilitated diffusion

Answer 21

solute combines with a transporter protein in the membrane

Question 22

Water can also be facilitated by _______

Answer 22

aquaporins

Question 23

passive ransport

Answer 23

molecules move along their concentration gradient

Question 24

active trasnport

Answer 24

molecules move against the concentration gradient (requires energy)

Question 25

3 functions of plasma membrane

Answer 25

1. isolate cell contents from environment
2. increase cellular [ ] of chemical reactants
3. Anchor proteins and other structures

Question 26

What three things cause damage to the integrity of the plasma membrane?

Answer 26

1. alcohols, 2. quaternary ammonium (detergents) 3. some antibiotics

Question 27

Whats part of a gram + cell wall?

Answer 27

thick peptidoglycan (up to 40 layers) and teichoic acids

Question 28

What is part of a gram - cell wall?

Answer 28

thin peptidoglycan, and an outer membrane

Question 29

Gram Stain is what 4 steps?

Answer 29

1. purple dye, 2. iodine, 3. alcohol, 4. safranin (pink, counter stain)

Question 30

What do atypical cell walls have that the other cell walls don’t?

Answer 30

mycolic acids (waxy lipids) and arabinogalactans (unusual sugars)

Question 31

3 Characteristics of Mycoplasmas

Answer 31

very simple, lack cell walls, sterols in their PM’s

Question 32

What effect does lysozyme have on peptidoglycan?

Answer 32

digests disaccharide

Question 33

What effect does penicillin have on peptidoglycan?

Answer 33

inhibits peptide bridges

Question 34

protoplast

Answer 34

cell wall completely removed (lysozyme)

Question 35

spheroplast

Answer 35

cell wall is almost completely removed (penicillin)

Question 36

What are protoplasts and spheroplasts susceptible to?

Answer 36

osmotic lysis (rupture)