Lecture 4

Question 1

Size range for prokaryotes

Answer 1

0.2um to >700um in diameter

Question 2

Size range for eukaryotes

Answer 2

10 to >200um in diameter

Question 3

advantages to being small

Answer 3

• more surface area realative to volume
• greater nutrient exchange per unit cell volume
• tend to grow faster

Question 4

Functions of membranes

Answer 4

• permeability barrier
• anchor for proteins
• site for energy conservation (ETC)

Question 5

The cytoplasmic membrane is __________ wide.

Answer 5

8-10nm

Question 6

The cytoplasmic membrane is stabilized by..

Answer 6

hydrogen bonds and hydrophobic interactions

Question 7

____ and ____ help stabilize the membrane by forming ionic bonds with negative charges on the phospholipids.

Answer 7

Mg2+, Ca2+

Question 8

Outer surface of cytoplasmic membrane

Answer 8

can interact with a variety of proteins that bind substrates or process large molecules for transport

Question 9

Inner surface of cytoplasmic membrane

Answer 9

interacts with proteins involved in energy‐yielding reactions and other important cellular functions

Question 10

intergral membrane proteins

Answer 10

firmly embedded in the membrane

Question 11

peripheral membrane proteins

Answer 11

one portion anchored in membrane

Question 12

____ linkages in phospholipids of Archaea.

Answer 12

Ether

Question 13

Bacteria and Eukarya have ____ linkages in phospholipids

Answer 13

ester

Question 14

Archaeal lipids lack _________; have _______ instead.

Answer 14

fatty acids, isoprenes

Question 15

Major lipids in archaea membranes are…

Answer 15

glycerol diethers and tetraethers

Question 16

Archaeal membranes can exist as lipid…

Answer 16

monolayers (high temperature), bilayers, or mixtures

Question 17

Polar and charged molecules must be…

Answer 17

transported

Question 18

transport proteins

Answer 18

accumulate solutes against the conc. gradient

Question 19

protein anchor

Answer 19

holds transport proteins in place; site of many proteins that participate in transport, bioenergetics, and chemotaxis

Question 20

energy conservation

Answer 20

site of generation and dissipation of proton motive force

Question 21

3 major classes of transport systems in prokaryotes

Answer 21

• simple transport
• group translocation
• ABC system

Question 22

Which of the 3 major classes of transport systems in prokaryotes require energy?

Answer 22

ALL; usually proton motive force or ATP

Question 23

simple transport

Answer 23

driven by the energy in the proton motive force

Question 24

group translocation

Answer 24

chemical modification of the transported substance driven by phosphoenolpyruvate

Question 25

ABC transporter

Answer 25

periplasmic binding proteins are involved and energy comes from ATP

Question 26

Simple transport of lactose into E. coli

Answer 26

with transporter lac permease, an energy-driven (proton motive force), symporter

Question 27

The phosphotransferase system in E. coli

Answer 27

- type of group translocation - best studied system - moves glucose, fructose, and mannose - five proteins required

Question 28

ABC (ATP-binding cassette) systems

Answer 28

- often involved in uptake organic compounds, inorganic nutrients, and trace metals - high substrate specificity

Question 29

Gram negatives of ABC systems

Answer 29

employ periplasmic‐binding proteins and ATP‐driven transport proteins

Question 30

Gram positives of ABC systems

Answer 30

employ substrate‐binding proteins and membrane transport proteins

Question 31

gram negative (pink) cell wall

Answer 31

peptidoglycan and outer membrane

Question 32

gram positive (purple) cell wall

Answer 32

peptidoglycan

Question 33

gram stain procedure

Answer 33

crystal violet, iodine, alcohol, safranin