Chapter 5

Question 1

Fluid-Mosaic Model

Answer 1

Fluid: phospholipid
Proteins: Mosaic
Model that explains structure and function of cell membrane

Question 2

Membrane fluidity

Answer 2

cholesterol and carbohydrates (glycoprotein/glycolipid)

Question 3

Membrane phospholipids

Answer 3

Glycerol, phosphate, fatty acids(2), hydrophobic (non polar, tails) and hydrophilic (polar, head)

Question 4

amphipathic

Answer 4

on the same molecule

Question 5

phospholipid head

Answer 5

hydrophilic, head

Question 6

phospholipid tails

Answer 6

hydrophobic, tails

Question 7

membrane proteins

Answer 7

proteins on plasma membrane

Question 8

Integral protein

Answer 8

Penetrate membrane, transmembrane, hydrophobic (alpha helices), hydrophilic channels(beta barrels)
membrane protein

Question 9

Peripheral

Answer 9

Attached to one layer
outside -> extracellular matrix
inside -> Cytoskeleton
Interact with integrals
membrane protein

Question 10

Transporters

Answer 10

channels: (doorway into cell)
movement of ion/molecule
may be voltage or ligand gated (open and close)
membrane protein

Carrier: Interact with specific molecules, binds and allows transport, may involve ATP
membrane protein

Question 11

Channel transporter

Answer 11

doorway into cell
movement of ion/molecule
may be voltage or ligand gated (open and close)
membrane protein

Question 12

Carrier transporter

Answer 12

Interacts with specific molecules, binds and allows transport, may involve ATP
membrane protein

Question 13

Enzyme membrane protein

Answer 13

Integral/peripheral
catalyze rxn.s on plasma membrane
membrane protein

Question 14

Signal transduction (indirect)

Answer 14

receptor protein, specific signal molecule
binding -> confirmation of change
transmit signal and propagate through cell
membrane protein

Question 15

Cell recognition

Answer 15

Glycoproteins, recognized by plasma membrane, temporary close interaction
membrane protein

Question 16

Embedded proteins

Answer 16

fully embedded into phospholipid bilayer

Question 17

Intracellular junctions

Answer 17

Close plasma membrane to plasma membrane connections
protein 1-> protein2
longer lasting communication
tissue formation

Question 18

Intra/extra cellular protein interactions

Answer 18

connection to extracellular matrix/ cytoskeleton
maintain cell shape and function
stabilize protein location
transmit signal out -> in

Question 19

Cholesterol

Answer 19

embedded in membrane, membrane fluidity ( we want cholesterol )
“goldilocks”

Question 20

High temp cholesterol

Answer 20

fluid plasma membrane

Question 21

Low temp cholesterol

Answer 21

viscous plasma membrane

Question 22

Carbohydrates

Answer 22

chain/branching outside of cell
bound to glycoproteins/lipids,
cell-cell recognition

Question 23

Permeability of Plasma membrane

Answer 23

Selectively (semi) permeable

Question 24

Free movement across PM

Answer 24

Passive diffusion, with channel, with carrier

Question 25

Passive diffusion

Answer 25

nonpolar molecules (nonpolar tails), gases, glycerol, free

Question 26

movement through PM channel

Answer 26

Aquaporins, free

Question 27

movement through PM carrier

Answer 27

Glucose, free

Question 28

"fee" required movement across PM

Answer 28

active transport, cost ATP, charged particles, large molecules

Question 29

simple chemical diffusion

Answer 29

concentration gradient present, down concentration gradient high -> low outside -> inside until equilibrated

Question 30

Spontaneous diffusion

Answer 30

No energy required, solute or solvent, often water

Question 31

Passive transport

Answer 31

Across PM

Question 32

Diffusion of water

Answer 32

High -> low across PM PM -> selective spontaneous, passive (no energy)

Question 33

Osmotic pressure

Answer 33

Created by H2O differences, pressure required to prevent osmosis

Question 34

Tonicity

Answer 34

relative amount of solute in a solution

Question 35

Hypertonic

Answer 35

large amount of solute

Question 36

Hypotonic

Answer 36

small/no amount of solute

Question 37

Isotonic

Answer 37

no gradient (= amount solute concentration)

Question 38

Animal cell hypotonic

Answer 38

cytolysis (cell bursts)

Question 39

Animal cell isotonic

Answer 39

:-)

Question 40

Animal cell hypertonic

Answer 40

crenation (cells shrink)

Question 41

Plant cell hypotonic

Answer 41

:-)

Question 42

Plant cell isotonic

Answer 42

small shrinkage

Question 43

Plant cell hypertonic

Answer 43

Plasmolysis (contraction of protoplast from cell wall)

Question 44

turgor pressure

Answer 44

force that pushes plasma membrane of cell against cell wall

Question 45

Facilitated diffusion

Answer 45

protein assisted diffusion, down concentration gradient high to low until equilibrated outside to inside no energy needed

Question 46

Active transport

Answer 46

Costs energy to move across plasma membrane

Question 47

Primary active transport

Answer 47

against concentration gradient low to high inside to outside moving ions energy required carrier proteins (uniport, symport, antiport)

Question 48

Uniporter

Answer 48

movement of single molecule across membrane active transport

Question 49

Symporter

Answer 49

movement of two or more molecules across membrane in the same direction active transport

Question 50

Antiporter

Answer 50

movement of two or more molecules across membrane in separate directions active transport

Question 51

Secondary active transport

Answer 51

Cotransport (symports) Movement of one facilitates movement of the 2nd against concentration gradient more bang for buck (only pay for one) Na+ pump (fuels glucose movement and cell uptake of glucose) Proton pump (fuels diffusion of H+ and sucrose movement)

Question 52

Difference between primary and secondary active transport

Answer 52

primary requires ATP (or chem energy) secondary uses electrochemical gradient (created by active transport) to fuel movement of molecules

Question 53

Bulk transport

Answer 53

membrane assisted continuous (same rate in and out)

Question 54

Endocytosis

Answer 54

Bringing into cell

Question 55

Phagocytosis

Answer 55

"cell eating" large macromolecules/whole organisms

Question 56

Exocytosis

Answer 56

Secretion outside of cell

Question 57

Pinocytosis

Answer 57

"cell drinking" small molecules microvilli of small intestine

Question 58

Transport vesicle

Answer 58

1. from golgi apparatus 2. along microtubule 3. travels to PM 4. fuses and releases contents outside 5. becomes part of PM replenishes/balanced by endocytosis [create vesicle]