membranes

Question 1

what is the word to describe being both hydrophobic and hydrophilic

Answer 1

amphipathic

Question 2

which direction do lipids move within the fluid mosaic, phospholipid bilayer

Answer 2

Latterly

Question 3

What happens to a membrane at lower temperatures

Answer 3

starts to solidify

Question 4

What does having unsaturated fatty acids in the phospholipid bilayer mean for the fluidity

Answer 4

kinks in the hydrophobic tails means the membrane cant pack so tight so is more fluid

Question 5

explain cholesterols effect on membrane fluidity

Answer 5

1) in moderate temperatures the membrane fluidity is reduced
2) in low temperatures cholesterol hinders packing

Question 6

Can both eukaryotes and prokaryotes regulate temperature

Answer 6

no, prokaryotes cannot regulate their temperature

Question 7

How to prokaryotes in environments that differ in temperature regulate membrane fluidity

Answer 7

Changing the lipid composition in their membranes

Question 8

what is a peripheral protein

Answer 8

bound to the hydrophilic surface of a membrane

Question 9

what is an integral protein

Answer 9

a protein that penetrate the hydrophobic core

Question 10

what is the name for a integral protein that spans the membrane

Answer 10

transmembrane protein

Question 11

what do hydrophobic regions of an integral protein consist of

Answer 11

one or more stretches of amino acids

Question 12

what are the 6 main functions of proteins in the membrane

Answer 12

1) transport
2) enzyme activity
3) signaling molecule receptor
4) cell- cell recognition
5) intracellular joining
6) attach to exoskeleton and extracellular matrix

Question 13

what type of molecules can dissolve in a lipid bilayer

Answer 13

hydrophobic and non-polar molecules

Question 14

what are the two types of passive transport

Answer 14

diffusion and facilitated diffusion

Question 15

what is dynamic equilibrium and is it achievable in a cell

Answer 15

once net diffusion is zero. however cells use nutrients fast, so there will always be a concentration gradient and a net diffusion

Question 16

what is tonicity and the three types

Answer 16

the ability of a surrounding solution to cause a cell to lose/ gain water
1) isotonic
2) hypotonic
3) hypertonic

Question 17

what is the term for a animal cell if placed in a hypotonic solution

Answer 17

lysed

Question 18

what is the term for a plant cell in a hypotonic solution

Answer 18

turgid

Question 19

what is the term for a plant cell in a isotonic solution

Answer 19

flaccid

Question 20

what is the term for a plant cell in hypertonic solution

Answer 20

plasmolyzed

Question 21

what is the term for the control of solute conc and water in osmotic organisms

Answer 21

osmoregulation- usually through a contractile vacuole

Question 22

what is a channel protein

Answer 22

hydrophilic channels for certain molecules/ ions

Question 23

what is an example of a channel protein

Answer 23

aquaporins transport water

Question 24

what is a carrier protein

Answer 24

bind to molecules and change shape to move molecule into the membrane

Question 25

what is the purpose of active transport

Answer 25

to carry ions and molecules against the concentration gradient

Question 26

what is a good example of active transport

Answer 26

the sodium/ potassium pump or a proton pump

Question 27

what are the two components of an electrochemical gradient/ membrane potential

Answer 27

1) electrical force (the ion conc gradient)
2) chemical force (effect of membrane potential on ion movement)

Question 28

what is co transport

Answer 28

when active transport of one molecule drives the transport of another

Question 29

exocytosis is when….

Answer 29

bulk transport is needed to remove or transport something outside the cell

Question 30

what are the three types of endocytosis

Answer 30

1) phagocytosis, food
2) pinocytosis, liquid
3) receptor mediated endocytosis, receptors recognize and hold a type of molecule for the cell to obtain