2.5

Question 1

what molecules can move freely accross cytoplasmic membrane

Answer 1

small uncharged, nonpolar molecules
some are somewhat hindered by their size and polarity

Question 2

examples of molecules that can move freely across cytoplasmic membrane

Answer 2

dissolved O2, dissolved CO2, small alcs and fatty acids

Question 3

what molecules is the cytoplasmic membrane impermeable to

Answer 3

large and charged molecules like Na+ and K+

Question 4

passive transport

Answer 4

requires no energy, molecules enter cell by moving down concentration gradient

Question 5

types of passive transport

Answer 5

simple diffusion
facilitated diffusion

Question 6

Active transport

Answer 6

requires energy, uptake into cell against concentration gradient

Question 7

types of active transport

Answer 7

simple transport
ABC transporters
Group transport

Question 8

Diffusion

Answer 8

-net movement of chemical down concentration gradient
high conc—> low conc
-requires no energy from cell

Question 9

Osmosis

Answer 9

diffusion of water through selectively permeable membrane along conc gradient

Question 10

low conc of solutes =

Answer 10

high conc of water

Question 11

Facilitated diffusion

Answer 11

diffusion of molecules across membrane via membrane protein acting as a channel

Question 12

example of facilitated diffusion

Answer 12

porins of OM

Question 13

specific facilitated diffusion

Answer 13

requires recognition element for specific molecules, and only those can molecules can fit into the element

Question 14

specific facilitated diffusion example

Answer 14

carrier proteins

Question 15

nonspecific facilitated diffusion

Answer 15

allow passage of molecules of a certain size and charge to pass

Question 16

nonspecific facilitated diffusion example

Answer 16

channel protein

Question 17

what does the cell regulate in facilitated diffusion

Answer 17

cell regulates production and activity of channels as it doesnt want to let stuff in or let stuff out sometimes

Question 18

where does energy required for active transport come fromq

Answer 18

1) stored chemical energy - ATP
2) dissipation of another conc gradient- something else moves along conc gradient

Question 19

simple transport

Answer 19

couple dissipation with takoing something in that is often H+

Question 20

types of simple transport and how they work

Answer 20

symporters and antiporters

Question 21

Syport

Answer 21

both molecules travel same direction

Question 22

Antiport

Answer 22

one molecule comes in the other goes out

Question 23

Main function of sodium proton antiporter

Answer 23

maintain homeostasis with pH and salt concentration
-lowers the ph, dissipating alkaline solution
-expells sodium, too much sodium affects protein folding

Question 24

lac permease symporter function

Answer 24

exploits proton motive force to drive uptake of lactose and other high energy foods into cell

Question 25

group translocation

Answer 25

type of active transport where transported substance bound by transporter and chemically modified during transport

Question 26

example of group translocation
where does the energy come from

Answer 26

phosphotransferase system
energy provided by hydrolysis of high E phosphate bond in PEP

Question 27

what else does phosphoration help with other than transporting sugars?

Answer 27

helpful metabolically

Question 28

ABC transporters

Answer 28

form of active transport
ATP binding cassette use atp to power the transport of substances across CM

Question 29

active binding cassette name

Answer 29

ABC transporters

Question 30

what provides energy in ABC transporters

Answer 30

2 ATPase (proteins) provide the energy

Question 31

what provides selective channel in ABC transporters

Answer 31

Transmembrane domain proteins provide selective channels

Question 32

what delivers molecule to the ABC transporter

Answer 32

Substrate binding protein binds molecule with high affinity and delivers it to the channel

Question 33

Gram negative bacteria SBPs

Answer 33

periplasmic binding proteins, capture ligand within periplasm

Question 34

Gram positive SBP

Answer 34

cytoplasmic binding protein tethered to cytoplasmic membrane

Question 35

ABC transporter example

Answer 35

Vitamine B12

Question 36

function of BtuB

Answer 36

OM barrel protein BtuB binds B12 via high affinity and transports it accross OM.

Question 37

what does BtuCD-F transporter do?

Answer 37

it transports it across cytoplasmic membrane, as BtuF has high affinity for B12, then B12 goes through another channel and is released in cytoplasm study pictures

Question 38

where does BtuB get energy to transport B12 across OM

Answer 38

proton motive force from TonB complex