UNIT 2 - Membrane transport

Question 1

what is the cell membrane composed of?

Answer 1

a phospholipid bilayer with embedded steroids (lipids), carbs and proteins

Question 2

what is the cell membrane?

Answer 2

surrounds the cells of all living things and separates the cell interior from the outside environment

Question 3

what does the cell membrane regulate?

Answer 3

the movement of materials in and out of the cell

Question 4

what is the fluid mosaic model?

Answer 4

describes the parts and structure that make up a cell membrane

Question 5

what influences membrane fluidity?

Answer 5

temperature of the bilayer and embedded steroids

Question 6

what increases membrane fluidity?

Answer 6

shorter fatty acid tails, and unsaturated fatty acid tails

Question 7

what does the polar head region of phospholipids contain?

Answer 7

glycerol and phosphate

Question 8

what does the non-polar tail of phospholipids contain?

Answer 8

2 fatty acid chains

Question 9

what part of phospholipids is hydrophilic?

Answer 9

the polar head region

Question 10

what part of phospholipids is hydrophobic?

Answer 10

the non-polar tails

Question 11

what do phospholipids allow go through the membrane?

Answer 11

small non-polar molecules

Question 12

what are proteins position in the cell?

Answer 12

floating freely in the bilayer or held in position by cytoskeleton

Question 13

what are integral proteins?

Answer 13

they span the bilayer and contain both hydrophobic/philic portions (R-groups)

Question 14

what are peripheral proteins?

Answer 14

they are attached to the surface of the membrane

Question 15

what do channel proteins do?

Answer 15

they allow movement of polar molecules or charged particles across the cell

Question 16

where do channel proteins move from?

Answer 16

they move from high concentration - low concentration

Question 17

what is aquaporin?

Answer 17

a special channel protein for the movement of water

Question 18

what are carrier proteins?

Answer 18

they interact with specific molecules or ions so they can cross the membrane

Question 19

what does transport for carrier proteins require?

Answer 19

requires energy (ATP)

Question 20

what do cell recognition proteins do?

Answer 20

they allow for cell to cell identification and prevent immune cells from targeting our body

Question 21

what is glycoprotein?

Answer 21

attached carbohydrate chain

Question 22

what are receptor proteins structure?

Answer 22

they have a specific shape that will allow certain molecules to bind to the cell

Question 23

where are enzymatic proteins located?

Answer 23

they are in the membrane of the mitochondria

Question 24

what do enzymatic proteins do?

Answer 24

speed up a specific metabolic reaction and are responsible for the synthesis of ATP

Question 25

what are glycoproteins?

Answer 25

carb chain attached to an integral protein

Question 26

what are glycolipids?

Answer 26

carb chain attached to a hydrophilic head of a phospholipid

Question 27

where do attached carbohydrate chains always occur?

Answer 27

on the extracellular side of the membrane

Question 28

what do glycolipids play a key role in?

Answer 28

cell-cell recognition and immune response

Question 29

what part do lipids play in the membrane of animal cells?

Answer 29

fluidity and permeability of the membrane

Question 30

all particles that enter or leave the cell must cross the _____?

Answer 30

cell membrane

Question 31

what is passive transport?

Answer 31

movement of molecules across a semipermeable membrane down the concentration gradient

Question 32

what is diffusion?

Answer 32

transport of small uncharged molecules from an area of high concentration to low concentration until equilibrium is reached

Question 33

concentration affect on rate of diffusion?

Answer 33

the greater the difference in concentration the faster the diffusion will proceed

Question 34

molecule size affect on rate of diffusion?

Answer 34

smaller substances diffuse quickly

Question 35

temperature affect on rate of diffusion?

Answer 35

higher temps. increase the rate of diffusion

Question 36

solubility affect on the rate of diffusion?

Answer 36

soluble molecules diffuse easily

Question 37

charge affect on the rate of diffusion?

Answer 37

charged or polar molecules do not pass through the membrane easily

Question 38

what is osmosis?

Answer 38

the diffusion of water across a membrane from an area of high water concentration to low concentration

Question 39

what happens in osmosis when solutes cannot pass easily across a membrane?

Answer 39

water moves instead to achieve equilibrium

Question 40

what is tonicity?

Answer 40

describes the solute concentration outside the cell compared to the concentration of the same solute inside the cell

Question 41

what is isotonic?

Answer 41

solute concentration is equal on both sides off membrane- cell stays the same size

Question 42

what is hypertonic?

Answer 42

solution outside cell is more concentrated than inside- causes cell to shrink/shrivel

Question 43

what is hypotonic?

Answer 43

solution outside the cell is less concentrated than inside- causes cell to swell

Question 44

what is facilitated transport?

Answer 44

when some molecules cannot pass through membrane, integral carrier or channel proteins are used to transport stuff in/out of cell

Question 45

what is active transport?

Answer 45

carrier proteins or vesicle formation in cell membrane use ATP to move molecules against concentration gradient: [low]--->[high]

Question 46

what is sodium potassium pump?

Answer 46

helps maintain osmotic equilibrium and membrane potential in cell

Question 47

what is endocytosis?

Answer 47

cell absorb outside material by engulfing it with cell membrane

Question 48

what is phagocytosis?

Answer 48

(cell eating) - large particles

Question 49

what is pinocytosis?

Answer 49

(cell drinking) - small particles, solutions

Question 50

what is receptor mediated?

Answer 50

proteins receive molecules and organize vesicle formation

Question 51

what is exocytosis?

Answer 51

vesicle fuses with membrane and spills contents to the outside?