Cells and Organelles Flashcards
1
Q
3 main components of cell membrane
A
phospholipids
cholesterol
proteins
2
Q
2 types of membrane proteins
A
integral
peripheral
3
Q
proteins embedded in the core of the plasma membrane
A
integral
4
Q
many integral proteins are __ proteins, meaning they extend all the way through the membrane
A
transmembrane
5
Q
integral/transmembrane proteins may function in cell __, but most tend to transport __ molecules across the cell membrane
A
signalling
large, polar
6
Q
membrane proteins that do not extend through the entire bilayer
A
peripheral
7
Q
3 common types of peripheral membrane proteins
A
receptors
adhesion proteins
recognition proteins
8
Q
recognition proteins are also known as __
A
glycoproteins
9
Q
common example of a recognition peripheral protein
A
major-histocompatibility complexes (MHC molecules)
10
Q
3 main factor that affect membrane fluidity
A
temperature
cholesterol
degree of phospholipid tail unsaturation
11
Q
__ particles can travel directly across the phospholipid bilayer via simple diffusion
A
small, uncharged, non-polar
12
Q
simple diffusion is the flow of substances __ their concentration gradient in a __ consuming process
A
down
non-energy
13
Q
__ does not utilize proteins to help particles across the membrane
A
simple diffusion
14
Q
osmosis is a type of __
A
simple diffusion
15
Q
__ molecules cannot travel directly across the bilayer
A
large, hydrophilic
16
Q
how large, hydrophilic molecules travel across the bilayer by transmembrane proteins
A
facilitated transport
17
Q
3 main types of facilitated transport
A
uniport
symport
antiport
18
Q
__ move 1 molecule in 1 direction
A
uniporters
19
Q
__ move 2 molecules in the same (1) direction
A
symporters
20
Q
__ move 2 molecules in opposite (2) directions
A
antiporters
21
Q
2 classes of transmembrane proteins involved with facilitated transport
A
channel
carrier
22
Q
__ proteins face the extracellular and intracellular environments of the cell at the same time
A
channel
23
Q
channel proteins are like tunnels for many __
A
small, polar molecules and ions
24
Q
__ diffusion describes a type of facilitated transport of particles down their concentration gradient through a __ protein
A
passive
channel
25
porins and ion channels are common examples of __ diffusion
passive
26
change their shape to facilitate the movement of molecules through the protein
carrier proteins
27
occurs when particles travel against their concentration gradient, which requires an energy input
active transport
28
active transport tends to rely upon __ proteins
carrier
29
2 types of active transport
primary
| secondary
30
type of active transport that uses the energy released from ATP hydrolysis
primary
31
Na+/K+ pump is a form of __ active transport
primary
32
Na+/K+ pump moves __ out of the cell and __ into the cell with the hydrolysis of 1 ATP
3 Na+
| 2 K+
33
secondary active transport depends on __ to generate free energy in the form of a concentration gradient
primary active transport
34
type of active transport that uses free energy to pump other molecules against their concentration gradient
secondary
35
bulk transport of large, polar molecules
cytosis
36
2 directions of cytosis
endocytosis into cell
| exocytosis out of cell
37
type of endocytosis where a cell engulfs undissolved materials
phagocytosis
38
during phagocytosis, the cell membrane will project __ to wrap around the sold
outward
39
phagocytosis forms __
vacuoles (phagosomes)
40
type of endocytosis where a cell engulfs dissolved materials
pinocytosis
41
during pinocytosis, the cell membrane will __ around the liquid
invaginate
42
pinocytosis forms __
vesicles
43
certain non-steroidal hormones target cells via which pinocytosis mechanism?
receptor-mediated endocytosis
44
receptor-mediated endocytosis forms __
vesicles
45
organelles are enclosed by a __
phospholipid bilayer
46
membrane-bound organelles are predominantly associated with which cell type?
eukaryotes
47
aqueous intracellular fluid
cytosol
48
everything within the cell (fluid and organelles)
cytoplasm
49
membrane-enclosed organelle that contains most of a eukaryotic cell's genetic material
nucleus
50
nucleus contains an aqueous __
nucleoplasm
51
inner and outer membrane of the nucleus
nuclear envelope
52
space between the inner and outer nuclear membranes
perinuclear space
53
dense and fibrous network of proteins associated with the inner membrane of the nuclear envelope
nuclear lamina
54
the nuclear lamina is made of __
intermediate filaments
55
functions of nuclear lamina
structural support to nucleus
| regulates DNA organization, DNA replication, and cell division
56
holes in nuclear envelope
nuclear pores
57
dense region in nucleus associated with ribosomal subunit assembly
nucleolus
58
is the nucleolus an organelle
no - not membrane bound
59
ribosomal subunits contain __ and __
rRNA
| proteins
60
eukaryotic __ are made in the nucleus and assembled in the cytosol
ribosomal subunits
61
what do ribosomes do
synthesize proteins
62
structure of a eukaryotic ribosome
60S + 40S = 80S
63
structure of a prokaryotic ribosome
50S + 30S = 70S
64
where are ribosomes found?
freely in cytosol or attached to the rough ER
65
__ ribosomes tend to make proteins that function within the cytosol of the cell
free
66
ribosomes that bind to the rough ER will synthesize proteins __
into the rough ER lumen
67
the rough ER is continuous with the __, which means the ER lumen is continuous with the __
outer nuclear membrane
| perinuclear space
68
what happens to proteins inside the rough ER
they are manipulated
69
what is a common manipulation for proteins in the rough ER
glycosylation to make glycoproteins
70
2 fates of proteins that enter the lumen of the rough ER
become part of the cell membrane
| exocytosis
71
synthesizes lipids and steroid hormones for export
smooth ER
72
function of smooth ER in liver
breaks down toxins and drugs
73
smooth ER of muscle cells that stores and releases Ca2+ ions
sarcoplasmic reticulum
74
the __ ER is not covered by ribosomes
smooth
75
the smooth ER is usually not attached to the __
outer nuclear membrane
76
ERs send vesicles to the __
cis-face of the the Golgi
77
vesicles travel from the __ to the __ of the Golgi, and the vesicle contents are manipulated along the way
cis-face
| trans-face
78
main function of the Golgi
direct molecules to their correct locations
79
organelles that break down nutrients/bacteria/cell debris
lysosomes
80
lysosomes receive vesicles containing digestive enzymes from the __
Golgi
81
lysosomes have a __ pH, so their enzymes can only function inside them
low (5)
| cytosol pH = 7
82
intracellular breakdown of unneeded/defective cellular components
autophagy
83
lysosomes function in __ when they release their contents into the cell
apoptosis
84
which cells have vacuoles?
all plants and fungi
| some animal, protist, bacteria
85
types of vacuoules
```
transport
food
central
storage
contractile
```
86
__ vacuoles move materials from organelle to organelle or from organelles to the plasma membrane
transport
87
__ vacuoles are temporary food holders that eventually merge with lysosomes for digestion
food
88
central vacuoles have a __ and exert __ when filled to maintain plant cell rigidity
tonoplast
| turgor
89
__ vacuoles (in plants) act similarly to lysosomes and storage vacuoles
central
90
__ vacuoles tend to store starches, pigments, and toxic substances
storage
91
__ vacuoles collect and pump excess water out of single-celled organisms
contractile
92
contractile vacuoles prevent __ in __ environments
lysis
| hypotonic
93
contractile vacuoles use __ transport
active
94
group of organelles/membranes that work together to modify, package, and transport proteins and lipids that are entering/exiting a cell
endomembrane system
95
components of the endomembrane system
```
nucleus/nuclear envelope
rough and smooth ERs
Golgi apparatus
lysosomes
vacuoles
cell membrane
```
96
break down fatty acids and some amino acids; also involved with detoxification
peroxisomes
97
alcohol detoxification occurs in the __ of liver cells
peroxisomes
98
are peroxisomes part of the endomembrane system?
no
99
peroxisomes __ vesicles from the Golgi apparatus
do not receive
100
peroxisomes generate __, which can produce dangerous reactive oxygen species
hydrogen peroxide
101
reactive oxygen species can create __
free radicals
102
peroxisomes contain an enzyme called __, which converts dangerous H2O2 radicals into harmless water
catalase
103
in plant cells, __ modify the by-products of photorespiration
peroxisomes
104
specialized peroxisomes that provide energy for a developing plant embryo
glyoxysomes
105
__ make ATP in all eukaryotes
mitochondria
106
__ carry out PSS in select eukaryotes
chloroplasts
107
the centrosome is an organelle found near the __ of animal cells
nucleus
108
a centrosome contains a pair of __, which work together to serve as __ during cell division in animal cells
centrioles
| microtubule organizing centers (MTOCs)
109
function of cytoskeleton
aids in cell structure, function, and movement in prokaryotes and eukaryotes
110
the cytoskeleton is found within the __ of prokaryotes/eukaryotes
cytoplasm
111
3 components of eukaryotic cytoskeletons
```
actin filaments (microfilaments)
intermediate filaments
microtubules
```
112
__ have the smallest diameter of the 3 cytoskeletal components
microfilaments
113
microfilaments are made of a __ of two actin filaments
double helix
114
actin monomers of a microfilament have __, so the microfilaments do too
directionality
115
actin can undergo rapid __, which makes microfilaments useful for cell movement
assembly/disassembly
116
examples of cellular processes that rely on microfilaments
amoeboid movement
cyclosis
cleavage furrow formation
muscle contraction
117
__ filaments provide cytoskeletal support for maintaining cell shape, and they are also found in the nuclear lamina
intermediate
118
example of common intermediate filament
keratin
119
keratin is concentrated in __
skin, hair, nails
120
intermediate filaments do not undergo __, so they are longer lasting
rapid assembly/disassembly
121
microtubules are a hollow tube, where the walls of the tube are a helical polymer of __
tubulin protein dimers
122
MTs are similar to microfilaments in the sense that they can grow and shrink __
rapidly
123
__ have directionality, so microtubules do too
tubulin dimers
124
main functions of microtubules
structural support
cell division
cilia/flagella
125
MTOCs are in __ cells
eukaryotic
126
what do MTOCs develop that is crucial to cell division?
spindle apparatus
127
the spindle apparatus guides chromosomes to opposite ends of the cell during __
karyokinesis
128
karyokinesis
nuclear division
129
3 main types of spindle apparatus microtubules
kinetochore
polar
astral
130
__ attach to a chromosome's kinetochore
kinetochore microtubules
131
__ microtubules connect to push the MTOC to opposite ends of the cell during division
polar
132
__ microtubules extend to the cell membrane and are involved with spindle apparatus orientation
astral
133
a centrosome is a type of MTOC in __ cells
animal
134
fungi and most plant cells do not contain a __ as their MTOC
centrosome
135
specialized cylinders of microtubules that inhabit the centrosome
centrioles
136
each centrosome has a mother and daughter centriole, oriented at a __
90 degree angle
137
each centriole is a hollow cylinder made of
9 triplets of microtubules
138
there is usually __ centrosome in a non-dividing cell
1
139
the centrosome will replicate during __ to prepare for cell division
S phase of interphase
140
the __ can form a basal body by attaching to the cell membrane
mother centriole
141
basal bodies are found at the base of each __
flagellum and cilium
142
basal bodies have a similar structure to centrioles, so they have a __ array
9x3
143
cilia and flagella have a different microtubule structure than basal bodies; they have a __ array
9x2
144
protein building block of prokaryotic flagella
flagellin
145
__ of a centrosome is a matrix of proteins that surround centrioles
pericentriolar material
146
the pericentriolar material is involved with __ and __ to the centrosome
microtubule nucleation
| securing microtubules
147
the process where tubulin dimers come together to form a microtubule
microtubule nucleation
148
__ determine the placement of the nucleus and organelles
centrioles
149
function of the extracellular matrix (ECM)
provides mechanical support in the area between adjacent animal cells
150
class of glycoproteins that exist in the ECM between animal cells
proteoglycans
151
the most common fibrous structural protein in the ECM is a protein called __
collagen
152
animal cells called __ will glycosylate collagen before secreting it
fibroblasts
153
glycosylated collagen will form long woven fibers called __, a major component of the ECM
collagen fibrils
154
which transmembrane protein connects the ECM to cells?
integrins
155
integrins interact with the ECM to signal for __
growth
division
differentiation
apoptosis
156
protein that connects integrins to the network of proteoglycans and collagen in the ECM
fibronectin
157
fibronectin connections help in the transduction of signals from __
the ECM to integrins
158
protein that behaves similarly to fibronectin; found in the basement membrane, which integrins attach to
laminin
159
unique carbohydrate-based structures that lie above the cell membrane in certain types of cells that do not make collagen and therefore cannot make an ECM
cell walls
160
cell walls lie __
above the cell membrane
161
cell walls are present in cells that cannot make __ and therefore cannot make an __
collagen
| ECM
162
which cell types have cell walls?
plants
fungi
bacteria
archaea
163
similarities between cell walls and ECMs
provide structural support, protection enhanced degree of filtration
164
do animal cells have a cell wall?
no - secrete collagen and make an ECM
165
hard, non-living structural polysaccharide that makes up the cell wall of a plant cell
cellulose
166
structural polysaccharide that makes up the cell walls of fungi
chitin
167
found in cell walls of certain bacteria
peptidoglycan
168
form the cell walls in archaea
polysaccharides
169
coat of glycolipids and glycoproteins that covers the surface of bacterial cell walls and some animal cell membranes
glycocalyx
170
function of glycocalyx
provide adhesive capabilities
act as infection barrier
act in cell-cell recognition
171
allow the ECM to connect to the cytoskeleton at the interior of an animal cell
cell-matrix junctions
172
2 types of cell-matrix junctions
focal adhesions
| hemidesmosomes
173
cell-matrix junctions that use actin filaments in the cell
focal adhesions
174
cell-matrix junctions that use intermediate filaments
hemidesmosomes
175
__ junctions connect adjacent cells
cell-cell
176
4 main types of cell-cell junctions
tight junctions
desmosomes
adherens junctions
gap junctions
177
protein junctions that provide a water-tight seal between cells
tight junctions
178
__ junctions ensure that materials must enter the cells to pass through the tissue
tight
179
tight junctions are characteristic of cells lining the __
digestive tract
180
in __ (cell-cell junctions) cytoskeletal keratin filaments attach to adhesion plaques, which bind transmembrane adhesion proteins that hold adjacent cells together
desmosomes
181
what are the adhesion proteins used by desmosomes?
cadherins
182
in __ (cell-cell junctions) cytoskeletal microfilaments attach to adhesion plaques, which bind transmembrane adhesion proteins that hold adjacent cells together
adherens junctions
183
adhesion proteins used by adherens junctions
cadherins
184
desmosomes and adherens junctions are types of __ junctions
anchor
185
anchoring junctions provide __ and hold cellular structures togehter
mechanical stability
186
where are anchoring junctions found?
skin epithelium
cervix
uterus
187
gap junctions allow for the passage of __ and small molecules between cells, but they prevent the __ of each cell from mixing
ions
| cytoplasms
188
common example of human cells that contain gap junctions
heart cells
189
small holes in the plasma membrane of cells that make gap junctions
connexons
190
connexons are made up of 6 membrane proteins called __
connexins
191
when a connexon of 1 cell lines up with a connexon of another cell, we have a __
gap junction
192
a sticky cement which attaches adjacent plant cell walls to each other
middle lamella
193
tunnels between adjacent plant cells, which consist of a narrow tube of the ER called a desmodubule
plasmodesmata
194
plasmodesmata are tunnels between adjacent plant cells, which consist of a narrow tube of the __ called a desmotubule
endoplasmic reticulum
195
material moves through plasmodesmata via the __ that surrounds the __
cytosol
| desmotubule
196
the relative solute concentrations for 2 solutions that are separated by a semipermeable membrane
tonicity
197
tonicity determines the extent and direction of solvent flow via __
osmosis
198
a low solute concentration also means a __ water concentration, and vice versa
high
199
osmosis makes the solute concentrations __ on both sides of the membrane
equal
200
solutions where the extracellular and intracellular environments have the same solute concentrations
isotonic
201
animal cells prefer __ environments because they will be in water balance
isotonic
202
if the solute concentration outside a cell were higher, it would be called a __ environment
hypertonic
203
in a __ environment, water will leave the cell via osmosis in an attempt to reduce the solute concentration outside the cell
hypertonic
204
the loss of intracellular fluid in hypertonic environments causes the cell to __
shrivel
205
if a cell in a hypertonic environment has a cell wall, it will experience __
plasmolysis
206
if the solute concentration is lower outside the cell than it is inside the cell, the environment is __
hypotonic
207
in a __ environment, water will travel via osmosis from the external environment and into the cell
hypotonic
208
animal cells will __ in hypotonic environments
swell --> lyse
209
plant cells prefer __ environments because the extra water goes into the central vacuole, resulting in the normal turgid state
hypotonic
210
3 types of intracellular circulation
brownian motion
cyclosis/streaming
endoplasmic reticulum
211
random particle movement due to kinetic energy that spreads suspended particles through the cytoplasm
brownian motion
212
circular motion of the cytoplasm around cell transport molecules
cyclosis/streaming
213
the __ provides a channel through the cytoplasm, from the plasma membrane to nuclear membrane
endoplasmic reticulum
214
2 types of extracellular circulation
diffusion
| circulatory system
215
__ can suffice for food/respiration in cells that are in close contact with the external environment
diffusion
216
used for the transport of materials through interstitial fluid (between cells) in more complex animals
diffusion
217
complex animals with cells that are too far from the external environment require a __
circulatory system
218
the circulatory system uses __
vessels (vasculature)
