Cliff's - Chapter 2 - Cells Flashcards

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1
Q

cell

A

basic functional unit of all living things

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2
Q

plasma membrane (cell membrane)

A

bounds cell

encloses nucleus and cytoplasm

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3
Q

cytoplasm consists of

A

organelles suspended in fluid matrix, cytosol

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4
Q

organelles

A

specialized bodies

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5
Q

cytosol

is

consists of

A

fluid matrix,

water, dissolved substances - proteins + nutrients

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6
Q

plasma membrane

function

A
  • separates internal metabolic events from external environment
  • controls movement of materials into and out of cell
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7
Q

plasma membrane

composition

A
  • double phospholipid membrane
  • (liquid bilayer)
  • polar hydrophlic heads form two outer surfaces
  • nonpolar hydrophobic tails point inwards
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8
Q

Peripheral proteins

A

attach loosely to inner or outer surface of membrane

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9
Q

integral proteins

A

extend into membrane

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10
Q

transmembrane proteins

A

type of integral protein

span across membrane (surface to surface)

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11
Q

integral proteins

form

A

amphipathic

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12
Q

amphipathic

A

hydrophobic + hydrophilic regions

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13
Q

fluid mosaic model

A

mosaic

scattered proteins within flexible matrix of phospholipid molecules

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14
Q

phospholipid membrane is selectively permeable

only these may freely pass:

A

small, uncharged, polar molecules

e.g. H2O, CO2

hydrophobic molecules

e.g. nonpolar mlc like O2, lipid-soluble mlc like hydrocarbons

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15
Q

phospholipid membrane

impermeable molecules:

A

large polar molecules

e.g. glucose

all ions

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16
Q

Channel proteins

(plasma membrane)

A

certain hydrophilic (water-soluble) mlc

polar + charged molecules

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17
Q

Ion channels

(plasma membrane)

A

ions

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18
Q

gated channels

A

ion channels in nerve and muscle cells

open and close in response to chem or electric stimuli

passge of specific ions (K+, Na+)

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19
Q

Porins

(plasma membrane)

A

certain ions

small polar molecules

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20
Q

aquaporins

(plasma membrane of certain cells)

A

e.g. kidney, plant roots

dramatically increase flow of H2O

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21
Q

Carrier proteins

(plasma membrane)

A

bind to specific mlc

mlc transferred across membrane after carrier proteins change shape

e.g. glucose via carrier protein

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22
Q

Transport proteins

(plasma membrane)

A

use ATP (energy)

active transport

e.g. Na+-K+ pump

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23
Q

active transport

A

ATP used to transport materials

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24
Q

Na+-K+ Pump

A

uses ATP to maintain higher conc of Na+ and K+ on opp. sides of plasma membrane

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25
Q

recognition proteins

function

(plasma membrane)

A

give each cell type unique ID

rec b/w self types

self cells vs. foreign cells

normal cells vs. infected cells (viruses)

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26
Q

recognition protein

(plasma membrane)

form

A

glycoproteins

oligosaccharide attached

oligosaccharide extends away from surface of membrane

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27
Q

oligosaccharide

A

short polysaccharide chains

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28
Q

glycoproteins

A

proteins with oligosaccharides covalently bonded to polypeptide side chains

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29
Q

adhesion proteins

(plasma membrane)

A

attach cells to neighboring cells

or

provide anchors for internal filmanets and tubules of cell

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30
Q

internal filaments and tubules of cell provide…

A

stability to cell

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31
Q

receptor proteins

(plasma membrane)

A

binding sites for hormones, trigger mlc

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32
Q

when hormones, trigger mlc bind to receptor proteins..

A

specific cell response activated

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33
Q

Cholesterol mlc distributed throughout plasma membrane provide

A

rigidity to membrane (animal cells)

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34
Q

sterols

A

function as cholesterol in plasma membrane in plant cells

provide rigidity to membrane

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35
Q

glycocalyx

def and function

A

carb coat

covers outer face of cell wall (bacteria)

covers outer face of plasma membrane (animal)

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36
Q

glycocalyx

form

A

oligosaccharides attached to glycolipids and proteins

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37
Q

glycolipids

A

membrane phospholipids

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38
Q

glyocalyx

depending upon cell, may provide (3):

A

adhesive capabilities

barrier to infection

markers for cell-cell recognition

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39
Q

Organelles

A

bodies within cytoplasm

serve to physically separate various metabolic reactions

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40
Q

nucleus bouned by

A

nuclear envelope

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41
Q

nuclear envelope consists of

A

two phospholipid bilayers (sim. to plasma membrane)

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42
Q

DNA form

A

spread out within nucleas in form of chromatin

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43
Q

when cell begins to divide, chromatin…

A

condenses into chromasomes

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44
Q

before dividing, chromosomes made up of

A

two long DNA molecules

various histone molecules

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45
Q

histones

A

protein

organize - coil DNA into nucleosomes

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46
Q

nucleoli

A

in nucleus

concentrations of DNA

manufacture subunits of ribosomes

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47
Q

during cell division, chromsomes separate in the

A

nucleus

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48
Q

ribosome

made up of…

A

RNA molecules and protein

2 subunits

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49
Q

ribosome subunits and unification

A

40S + 60S

manufactured in nucleoli

subunits move nuclear envelope —> cytoplasm

combine –> 80S in cytoplasm

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50
Q

ribosome function

A

in cytoplasm - help assemble amino acids —> proteins

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51
Q

S Value

(Svedberg unit)

A

how readily product forms sediment in centrifuge

larger values = heavier products

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52
Q

Endoplasmic Reticulum

(ER)

form

2 types

A

stacks of flattened sacs

cross section: series of maze-like channels

rough (with ribosomes)

smooth (without ribosomes)

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53
Q

ER

function (general)

A

production of various materials

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54
Q

rough ER

A

has ribosomes on surface

creates glycoproteins

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55
Q

how does rough ER create glycoproteins?

A

attaches polysaccharide groups to polypeptides as they are assembled by ribosomes

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56
Q

smooth ER

function

A

various activities

synthesis of lipids and hormones

esp in cells that produce these for export from cell

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57
Q

smooth ER in liver cells

A

breakdown of toxins

drugs

toxic by-products from cellular rxns

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58
Q

Golgi apparatus

(golgi complex, golgi body)

form

A

group of flattened sacs

arranged like stack of bowls

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59
Q

gogli

fxn

A

modify and pack proteins and lipids into vesicles

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60
Q

vesicles

form

A

small

spherically shaped sacs

bud from outside surface of golgi

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61
Q

vesicles

fxn

A

merge with plasma membrane

release contents to outside of cell

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62
Q

Lysosomes

form

A

vesicles from golgi that

contain digestive enzymes

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63
Q

lysosomes

fxn

A

break down food

cellular debris

foreign invaders (bacteria)

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64
Q

lysosomes

characteristics (pH)

A

low pH (favorable to enzymes)

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65
Q

lysosomes occur in

A

animal cells

NO plant cells

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66
Q

if an enzyme escapes from lysosome

A

it will be inactive in neutral pH of cytosol

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67
Q

Peroxisomes

fxn

A

break down various substances

e.g. H2O2, fatty acids, amino acids

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68
Q

peroxisomes are common in these kinds of cells

A

liver and kidney

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69
Q

peroxisomes fxn in liver and kidney cells

A

break down toxic substances

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70
Q

peroxisomes in plant cells

A

modify by-products of photorespiration

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71
Q

photorespiration

A

CO2 diverted from use in photosynthesis

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72
Q

glyoxysomes

A

peroxisomes in germinating seeds

break down fatty acids —> energy for growth

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73
Q

Mitochondria

A

carry out aerobic respiration

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74
Q

aerobic respiration

A

energy (ATP) obtained from carbs

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75
Q

chloroplasts

A

carry out photosynthesis

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76
Q

photosynthesis

A

plant process

incorporate energy from sunlight into carbohydrates

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77
Q

three protein fibers, in decreasing diameter

A

microtubules

intermediate filaments

microfilaments

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78
Q

microtubules

intermediate filaments

microfilaments

A

protein fibers involved in shaping or coordinating movements of cytoskeleton

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79
Q

cytoskeleton

A

internal structure of cytoplasm

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80
Q

microtubules made of

A

protein tubulin

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81
Q

microtubules

fxn

A

support and motility for cellular activities

82
Q

microtubules found in

A

spindle apparatus

flagella

cilia

83
Q

spindle apparatus

A

guides movement of chromosomes during cell division

84
Q

flagella and cilia

A

project from plasma membrane

provide motility to cell

85
Q

intermediate filaments

A

maintain shape of cell

86
Q

microfilaments made of

A

protein actin

87
Q

microfilaments involved in

A

cell motility

88
Q

microfilaments found in

A
  1. muscle cells
  2. cells that move by changing shape

e.g. phagocytes

89
Q

phagocytes

A

white blood cells

wander through body attacking bacteria and other foreign invaders

90
Q

flagella and cilia

A

protrude from cell membrane

make wavelike movements

91
Q

flagella

A

long, few

move in snakelike motion

92
Q

cilia

A

short, many

move with back and forth motion

93
Q

propels sperm

A

single flagellum

94
Q

line respiratory tract and sweep away debris

A

numerous cilia

95
Q

structure of flagella and cilia

A

microtubules arranged in 9+2 array

9 doublets of microtubules arranged in a circle around a pair of microtubules

96
Q

Centrioles and basal bodies act as

A

microtubule organizing centers (MTOCs)

97
Q

both centrioles and basal bodies are made up of

A

nine triplets of microtubules arranged in a circle

98
Q

a pair of centrioles are enclosed in the

A

centrosome

99
Q

centrioles in centrosome located outside nuclear envelope gives rise to…

A

microtubules that make up spindle apparatus (used during cell divison)

100
Q

at the base of each flagellum and cilium are

A

basal bodies

101
Q

basal bodies at the base of each flagellum and cilia

fxn

A

organize development of flagellum and cilia (microtubules)

102
Q

cenrioles are not present in

A

plant cells

103
Q

only lower plants

e.g. mosses and ferns

with motile sperm have these

(re: microtubules)

A

flagella and basal bodies

104
Q

Vacuoles and vesicles are

A

fluid-filled, membrane-bound bodies

105
Q

transport vesicles

fxn

A

move materials

bw organelles

bw organelles and plasma membrane

106
Q

food vacuoles

A

temporary receptacles of nutrients

107
Q

food vacuoles often merge with

A

lysosomes

108
Q

digestive enzymes in lysosomes…

(fxn re: food vacuoles)

A

break down the food transported from food vacuoles

109
Q

storage vacuole store:

(plants)

A

starch

pigments

toxic substances (e.g. nicotine)

110
Q

central vacuoles

form + location

(plants)

A

large bodies

occupy most of interior of certain plant cells

111
Q

central vacuoles

fxn

A

exert turgor (when fully filled) on cell walls —> maintain rigidity of cell

store nutrients

carry other fxns of lysosomes (animal cells)

112
Q

turgor

A

pressure

113
Q

contractile vacuoles

found in

A

single celled organisms

114
Q

contractile vacuoles

fxn

A

collect + pump excess water out of cell

(single celled organisms)

115
Q

extracellular region

A

area outside plasma membrane

116
Q

cell walls found in

A

plants

fungi

protists

bacteria

117
Q

cell walls

location

A

outside plasma membrane

in extracellular region

118
Q

composition of cell wall in plants

A

cellulose

119
Q

composition of cell wall in fungi

A

cellulose

or

chitin

120
Q

cellulose

A

polysaccharide

beta-glucose

121
Q

chitin

A

modified polysaccharide

differs from cellulose - one OH replaced by N-group

122
Q

extracellular matrix found in

(organism)

A

animals

123
Q

extracellular matrix found in

(area)

A

space bw adjacent cells

(beyond plasma membrane and glycocalyx)

124
Q

extracellular matrix

composition

A

fibrous structural proteins

adhesion proteins

polysaccharides secreted by cells

125
Q

extracellular matrix

fxn

A

mechanical support

helps bind adjacent cells together

126
Q

most common substance in extracellular matrix

A

collagen

127
Q

cell junctions

A

anchor cells to one another

or

passageway for cellular exchange

128
Q

types of cell junctions

3

A

anchoring junctions

tight junctions

communicating junctions

129
Q

anchoring junctions

A

protein attachments between adjacent cells

in animals

130
Q

desmosome

A

anchoring junction

keratin + other proteins

bind adjacent cells together

provide mechanical stability to tissues

associated with protein filaments that extend into interior of cell and hold cellular structures together (pg 37)

131
Q

tight junctions

A

tighty stitched seams bw cells

animal

completely encircles each cell

acts as seal - prevents passage of materials bw cells

132
Q

tight junctions characteristic of cells that

A

line digestive tract:

materials req’d to pass through cells to penetrate blood stream

pass through cells as opposed to intercellular space!!

133
Q

Communicating Junctions

A

passageways bw cells

transfer chemical or electrical signals

134
Q

2 types of communicating junctions

A

gap junctions

plasmodesmata (plural)

plasmodesma (singular)

135
Q

gap junctions

A

narrow tunnels bw cells

animals

136
Q

gap junctions consist of

A

proteins - connexins

137
Q

connexins prevent/allow

(gap junctions)

A

prevent: cytoplasms of each cell from mixing
allow: passage of ions and small molecules

138
Q

gap junctions allow for communication bw cells via

A

exchange of material

transmission of electrical impulses

139
Q

gap junctions are like ____ of two adjacent cells

A

channel proteins

140
Q

gap junctions

namesake

A

proteins of each cell extend beyond plasma membrane before they meet

small gap occurs bw two plasma membranes

141
Q

plasmodesmata

(singular: plasmodesma)

A

narrow channels

plant cells

142
Q

plasmodesmata

fxn

A

desmotubule (narrow tube of ER), surrounded by cytoplasm and plasma membrane, passes through channel

143
Q

material exchange through plasmodesma occurs through

A

cytoplasm surrounding desmotubule

144
Q

plant cells

(3 defining characteristics)

A

cells walls

chloroplasts

central vacuoles

145
Q

animal cells

3 definining characteristics

A

lysosomes

centrioles

cholesterol

146
Q

eukaryotes include all organisms except

A

bacteria

cyanobacteria

archaebacteria

147
Q

prokaryotes include

A

bacteria

cyanobacteria

archaebacteria

148
Q

prokaryotes lack all organelles except

(5)

A

plasma membrane

DNA molecule

ribosomes

cytoplasm

cell wall (often)

149
Q

prokaryotes do not have a

(vs. euk)

A

nucleus

150
Q

hereditary material in prokaryotes exists as

(vs. euk)

A

single DNA molecule

no proteins (as in DNA of eukaryotic chromosomes)

151
Q

prokaryotic ribosomes are

(vs euk)

A

smaller

70S

subunits: 50S + 30S

152
Q

eukaryote ribosomes

(composition)

(vs. prok)

A

80S

subunits:

60S + 40S

larger than prokaryotes

153
Q

cell walls of bacteria and cyanobacteria

(when present)

constructed from

(vs euk)

A

peptidoglycans

154
Q

peptidoglycan

A

polysaccharide protein molecule

155
Q

cell walls of archaebacteria contain

do not contain

(vs. euk)

A

various polysaccharides

no:

peptidoglycans

cellulose (plants)

chitin (fungi)

156
Q

flagela

when present in prokaryotes

are not constructed of

(vs. euk)

A

microtubules

157
Q

selectively permeable membrane

(movement of substances)

A

allows only specific substances to pass

e.g. plasma membrane

158
Q

solvent

(movement of substances)

A

substance whose movement is being described

159
Q

solute

(movement of substances)

A

substance dissolved in solvent

160
Q

hypertonic solute

A

higher concentration of solutes

161
Q

hypotonic solute

A

lower concentration of solutes

162
Q

isotonic solute

(relative to another region)

A

equal concentration of solutes

163
Q

hypertonic solute

A

higher concentration of solutes

164
Q

movement of substances may be ___ or ____

A

passive or active

165
Q

active movement of substances requires ____

and usually ____

A

expenditure of energy

occurs up a gradient

166
Q

Bulk flow

A

collective movement of substances in same direction

due to force or pressure

167
Q

e.g. of bulk flow

A

blood moving through vessel

168
Q

passive transport

A

movement of substances

higher conc. —> lower conc.

down conc. gradient

does not require expenditure of energy

169
Q

simple diffusion

aka diffusion

(passive transport)

A

net movement of substances from higher conc. –> lower conc

result of:

all mlc (atoms, ions) in random and constant motion

motion independent of other mlc

some mlc against gradient, some down gradient (random)

net = overall result of movement

170
Q

ultimate result of diffusion

(passive transport)

A

equilibrium

mlc uniformly distributed but continue to move randomly

171
Q

osmosis

(passive transport)

A

diffusion of water mlc across selectively permeable membrane

172
Q

when water moves into body by osmosis ____ may build up inside body

A

hydrostatic pressure (osmotic pressure)

173
Q

turgor pressure

A

osmotic pressure

water enters cells of plants and microorganisms

174
Q

dialysis

(passive transport)

A

diffusion of solutes across selectively permeable membrane

*term usually used when:

different solutes separated by selectively permeable membrane

175
Q

plasmolysis

(passive transport)

A

water out of cell (osmosis)

results in collapse of cell

176
Q

plasmolysis esp common in

A

plant cells

w/ central vacuoles

177
Q

facilitated diffusion

(passive transport)

A

diffusion of solutes or water through channel proteins in plasma membrane

*water can pass through plasma membrane w/o aid, but aquaporins increase rate of transfer

178
Q

___ release rate of transfer of water across selectively permeable membranes

type of channel protein

(facilitated diffusion - passive transport)

A

aquaporins via facilitated diffusion

179
Q

countercurrent exchange

(passive transport)

A

diffusion of substances bw two regions

substances moving by bulk flow in opposite directions

180
Q

e.g. countercurrent exchange

A
  • direction of water flow through gills of fish opposite flow of blood in blood vessels
  • diffusion of oxygen from water –> blood maximized because
  1. relative motion of mlc bw two regions increased
  2. conc. gradients bw two regions remain constant along area of contact
181
Q

Active transport

A

movement of solutes against gradient

requires expenditure of energy (usually ATP)

182
Q

transport proteins in plasma membrane transfer solutes via

A

active transport

183
Q

transport proteins transfer these solutes across plasma membrane

A

small ions (Na+, K+, Cl-, H+)

amino acids

monosaccharides

184
Q

Vesicular Transport

A

uses vesicles or other bodies in cytoplasm to move macromolecules or large particles aross plasma membrane

185
Q

types of passive transport

(6)

A
  1. simple diffusion (diffusion)
  2. osmosis
  3. dialysis
  4. plasmolysis
  5. facilitated diffusion
  6. countercurrent exchange
186
Q

types of vesicular transport

A
  1. exocytosis
  2. endocytosis
187
Q

types of endocytosis

(vesicular transport)

A
  1. phagocytosis
  2. pinocytosis
  3. receptor-mediated
188
Q

exocytosis

A

vesicles fusing with plasma membrane

releasing contents to outside of cell

189
Q

exocytosis common when

A

cell produces substances for export

190
Q

endocytosis

A
  • plasma membrane merges to engulf substance outside of cell
  • substance enters cytoplasm enclosed in a vesicle
191
Q

phagocytosis

(endocytosis)

“cellular eating”

occurs when

A

undissolved material enters cell

192
Q

phagocytosis

mechanism

A

plasma membrane wraps around solid material

engulfs it

forms phagocytic vesicle

e.g. white blood cells (phagocytes) attack and engulf bacteria

193
Q

pinocytosis

(endocytosis)

“cellular drinking”

occurs when

A

dissolved substances enter cell

194
Q

pinocytosis

mechanism

A

plasma membrane folds inward to form channel allowing liquid to enter

plasma membrane closes off channel

encircling liquid inside of vesicle

195
Q

receptor-mediated

(endocytosis)

occurs when

A

specific molecules in fluid surrounding cell bind to specialized receptors that concentrate in coated pits in plasma membrane

196
Q

receptor mediated endocytosis

mechanism

A

membrane pits, receptors, specific molecules (ligands)

fold inward –> formation of vesicle

197
Q

e.g. receptor mediated endocytosis

A

proteins that transport cholesterol in blood (LDL)

certain hormones

target specific cells via rme

198
Q

LDL

A

low-density lipoproteins

199
Q

receptor mediated endocytosis is a type of

A

pinocytosis

200
Q
A