(not all on exam) Cell Structure, Passive + Active Transport Flashcards
1
Q
what do all cells do?
4 points
A
digest nutrients
excrete waste
synthesize chemicals
reproduce
2
Q
what is
cell theory
3 points
A
all life composed of 1+ cells
cell is the smallest unit of life
cells can only come from other cells that already exist
3
Q
common features of all cells
2 points (organelles)
A
cell membrane
cytoplasm
for most cells: presence of nucleus + DNA
4
Q
classifying cells
A
prokaryote, eukaryote
depends on type of nucleus
5
Q
what is
cytoplasm
A
everything within the cell membrane, excluding nucleus
includes liquid and organelles
6
Q
what is
cytosol
A
liquid part inside cell
7
Q
extension of nuclear membrane
A
rough ER
8
Q
role of nucleus (if the mitochondria is the powerhouse then what is the nucleus)
A
directs cell activities
9
Q
hereditary information is stored in…?
A
nucleus (chromosomes (DNA))
10
Q
chromosomes store
A
genes
11
Q
purpose of
genes
A
has instructions on making a specific protein
12
Q
nuclear envelope is made of
A
2 lipid bilayers
13
Q
what do plant cells have that animal cells don’t
A
chloroplast, central vacuole
14
Q
present in animal cells and not plant cells
A
centrioles
15
Q
nuclear membrane is made of
A
1 lipid bilayer
16
Q
property of
nuclear membrane
A
selectively permeable
17
Q
embedded in nuclear membrane
A
proteins, e.g. receptors, transporters
18
Q
can cross the nuclear membrane freely
A
water + some gasses
19
Q
where are ribosomes assembled
A
nucleolus
20
Q
what is the nucleolus
physical characteristics + position
A
dense, dark region within the nucleus
21
Q
function of nucleolus
A
assemble subunits of ribosomes from proteins + RNA
22
Q
what is the nucleoplasm
A
semifluid interior portion of the nucleus
23
Q
chromatin is
A
all DNA molecules and associated proteins in the nucleus
24
Q
what is the endomembrane system
A
a group of interacting organelles b/w the nucleus and cell membrane
25
function of endomembrane system
make lipids, enzymes, proteins for use in cell
26
main organelles involved in endomembrane system
nucleus, ER, vesicles, golgi body
27
physical description of ER
lots of folds, shaped like flattened sacs + tubes
28
ER
endoplasmic reticulum
29
rough ER vs smooth ER
| physical characteristics
rough ER covered in ribosomes
30
rough ER function
polypeptide chains are folded and take on their final complex structure (occurs in the interior of the ER)
31
function of ribosomes on rough ER
synthesize polypeptide chains
32
function of smooth ER
contains enzymes that produce lipids, break down material
33
example of material broken down by smooth ER
carbs, fatty acids, some drugs + poisons
34
what are vesicles
sac-like organelles
35
how do vesicles form
bud from other organelles or cell membrane
36
examples of vesicles
| 3 points
peroxisomes, vacuoles, lysosomes
37
organelles without a membrane
| 2 points
ribosome, centriole
38
purpose of transport vesicles
transport substances within a cell, or release them from the cell
| secretory vesicles release substances, transport vesicles transport subs
39
golgi body physical characteristics
folded membrane, looks like a stack of flat sacs
40
function of golgi body
finalize peptide chains and lipids (from ER)
transport products using vesicles
41
how does the golgi body modify peptide chains + lipids
enzymes ! may attach phosphate groups or sugars, or cut chains
42
function of nucleus
protect + control access to DNA
43
where are lipids synthesized
smooth ER
44
organelle that generates ATP
mitochondria
45
function of chloroplast
produce sugars using light energy, CO2 and H2O
46
function of peroxisome
digest fatty acids and amino acids
47
function of vacuoles
isolate and dispose of waste, debris, toxic materials
48
function of lysosomes
carry out intracellular digestion and waste disposal using powerful digestive enzymes
49
which organelle inactivates toxins
peroxisome
50
which organelle aids in storage, and contains waste?
vacuole
51
purpose of vacuole unique to plants
maintain cell size and shape
52
function of centriole
produces microtubules for cytoskeleton, involved in cell division
53
function + composition of cilia
movement, made of microtubules
54
function of flagella
movement
55
properties of cell membrane
fluid, selectively permeable
56
name of structure of cell membrane
fluid mosaic model
57
cell membrane is made up of (molecule)
phospholipid molecules
58
cell membrane general structure
2 layers - bilayer
59
each layer of the cell membrane is called
a leaflet
60
intracellular
inside cell
61
something on the outside leaflet of the cell membrane is called
extracellular
62
a watery environment is
polar
63
molecule that forms membranes around all organelles
phospholipids
64
another name for intrinsic protein
integral protein
65
# meaning of
transmembrane
spans the entire width of the bilayer
66
function of integral proteins
| 4 points
structural support, recognition, communication, transport
67
proteins responsible for recognition
| within the cell membrane
## Footnote
e.g. in immune system
intrinsic proteins and glycoproteins
68
proteins responsible for communication
| within the cell membrane
intrinsic and glycoproteins
69
proteins responsible for structural support
| within the cell membrane (maintain shape)
integral and peripheral
| peripheral provides support for other proteins
70
function of glycoproteins
attachment site for other cells
communication + recognition of proteins
71
proteins responsible for transport
| within cell membrane
## Footnote
regulate molecules coming in and out of cell
integral proteins
72
types of proteins embedded in cell membrane
| 3 points
integral/intrinsic, glyco-, peripheral proteins
73
membrane protein classification
| 2 classes
polytopic, monotopic
74
definition of polytopic
faces both sides of the membrane
75
what is a glycoprotein
protein containing a sugar/carb bound to an amino acid
76
what is an integral protein
a protein embedded in the lipid bilary
| typically transmembrane
77
single pass
| polytopic protein
crosses membrane once
78
protein that crosses the cell membrane multiple times
multi-pass
79
monotopic
does not span entire bilayer, only on 1 leaflet/side
80
examples of transmembrane proteins
receptor, recognition, transport
81
attached to glycoproteins
carbohydrate groups
82
example of non transmembrane proteins
| 1
peripheral proteins
83
how are peripheral proteins bound to the membrane?
non-covalently
84
function of intracellular peripheral proteins
communication
85
function of extracellular periipheral proteins
structural support
86
receptor protein function
usu used as signalling molecules
87
how do receptor proteins work
ligand binds to binding site
88
example of recognition protein
glycoprotein - carb group helps identify cells
89
2 types of transport proteins
channel, carrier/pump
90
2 types of channel proteins
ungated/leak, gated
91
how do channel proteins work
no energy required, move small molecules/charged ions through tunnel-like proteins
92
ungated channels are
always opened
93
gated proteins
have open and closed conformations
94
how do gated proteins open/close
stimulated by changes in environment
95
carrier proteins vs channel proteins
carrier undergo conformational changes
96
what type of transport are carrier proteins involved in
passive and active
97
intracellular peripheral proteins are attached to
cell cytoskeleton, anchored/immobile on membrane
98
what is the cytoskeleton
a network of fibers extending throughout the cytoplasm
99
property of cytoskeleton
dynamic, easily dismantled and reassembled
100
3 components of cytoskeleton
microfilament, intermediate filament, microtubules
101
microfilaments made of
2 intertwined strands of actin
102
intermediate filaments made of
fibrous protein supercoiled
103
microtubules made of
hollow tube of 13 tubulin columns
104
microfilament functions (2)
maintain cell shape, muscle contraction
105
intermediate filament function
anchor organelles and cytosolic proteins
106
microtubule functions (2)
path for organelle/vesicle/chromosome movement, cell motility
107
organelles involved in cell motility
cilia, flagella
108
ecm made of
glycoproteins secreted by cells
109
function of extracellular matrix (3 points)
cell signalling, anchors cell - supports cell structure, separates tissue
110
where are carbs found (cell membrane)
extracellular side of the membrane
111
glycolipid
carb + lipid (or phospholipid)
112
function of carbs in cell membrane
identify the cell, act as a signaller for communication between cells
113
where is cholesterol found in the cell membrane
within fatty acid tails of bilayer
114
function of cholesterol in cell membrane
stabilize membrane
115
what affects fluidity of membrane
cholesterol, temperature, saturation of fatty acids, hydrophobic restrictions
116
how does saturation of fatty acids affect membrane fluidity
unsaturated = more fluid (kinks), saturated = viscous (packed too tightly)
117
5 types of mvmt w/i membrane
lateral diffusion, rotation, swing, flexion, transverse diffusion/flip flop
118
what is lateral diffusion
phospholipids transpose with neighbouring molecules (same leaflet)
119
what is swing (phospholipids)
tails move from side to side
120
what is flexion (phospholipids)
contractions
121
what is transverse diffusion
phospholipids move from 1 leaflet to the other
122
flipase
facilitates transverse diffusion
123
2 useful properties of cholesterol
large molecule size, non polar
124
how does cholesterol stabilize the membrane
large size interrupts intermolecular forces, non polarity stabilizes hydrophobic interactions + fills in kinks for unsaturated phospholipids
125
large size of cholesterol is more significvant
at low temperatures
126
non polarity of cholesterol is more significant
at high temperatures
127
importance of transverse motion being rare
helps maintain membrane asymmetry
128
2 types of cell junctions/cell adhesions
channel-forming, occluding
129
what are gap junctions
membrane proteins line up and form a channel, creates gaps that connects animal cells
130
occluding/tight junctions
form impermeable barriers between cells
131
homeostasis
constant internal environment is maintained despite changes in external environment
132
maintaining cellular environments is similar to
homeostasis in the body
133
2 forms of cellular transport
active, passive
134
3 types of passive transport
diffusion, osmosis, facilitated diffusion
135
simple diffusion
occurs directly through lipid bilayer
136
facilitated diffusion
occurs through a channel or carrier protein
137
molecules that go through facilitated diffusion
typically ions
138
proteins that facilitate osmosis
aquaporins
139
kmt full word
kinetic molecular theory
140
what is the kmt (3 points)
particles in constant random motion
particles collide, bounce off e/o, spread out
molecular collisions cause diffusion
141
another name for constant random motion
brownian motion
142
diffusion occurs until
equilibrium achieved
143
characteristics of molecules that go through simple diffusion
small, neutral molecules (e.g. O2 CO2)
144
concentration gradient relevance to diffusion
particles move from high concentration areas to low concentration areas
145
after equilibrium has been reached
molecules continue to move across the membrane, concentrations stay the same, no net mvmt
146
3 factors that affect diffusion
concentration, temperature, pressure
147
concentration effects on diffusion
increased concentration = increased speed of diffusion - more molecules = more collisions
148
how can diffusion rate increase
more collisions b/w molecules
149
temperature effects on diffusion
increased temperature = increased rate of diffusion
150
pressure effects on diffusion
increased pressure = increased rate of diffusion
151
3 types of solutions
hyper-, hypo-, isotonic
152
tonicity is
the osmotic pressure due to a diff. in concentration across a semi-permeable membrane
153
tonicity is affected by
solutes unable to cross the membrane
154
hypertonic solution definition
concentration of solute is higher outside than inside the cell
155
hypotonic solution definition
concentration of solute is lower outside than inside the cell
156
isotonic solution definition
concentration of solute is equal outside and inside the cell
157
shriveled cells were
placed in a hypertonic solution
158
lysed cells were
placed in a hypotonic solution
159
flaccid plant cells were
placed in an isotonic solution
160
tonicity related terms that only apply to plants
turgid, flaccid
161
water mvmt in hypertonic solution
water diffuses outwards
162
water mvmt in hypotonic solution
water diffuses inwards
163
water mvmt in isotonic solution
water diffuses in and out at an equal rate
164
what happens to cells in a hypertonic solution
shriveled, plasmolyzed
165
what happens to cells in a hypotonic solution
lysed
166
what happens to rbc in hypertonic solution
crenation
167
what happens to rbc in hypotonic solution
hemolysis
168
crenation occurs when
hypertonic solution, higher solute concentration outside of cell
169
hemolysis occurs when
hypotonic solution, higher solute concentration inside of cell
170
is facilitated diffusion active or passive
passive
171
example of molecules that use facilitated diffusion
K+ Na+ Cl-
172
moleculues that use facilitated diffusion
larger hydrophilic molecules
173
speed of facilitated diffusion depends on
proteins available, not concentration gradient
174
aquaporin charge
inside ins positively charged, outside is neutral
175
why do ions use channel proteins
have trouble crossing hydrophobic core
176
function of aquaporins
speed up diffusion of water
177
carrier proteins (active or passive)
passive
178
pumps (active or passive)
active
179
molecules that use carrier proteins
charged particles + large uncharged molecules (e.g. K+, glucose)
180
moving against the concentration gradient requires
active transport
181
active transport requires
energy from breakdown of atp
182
atp full word
adenosine triphosphate
183
atp rxn
atp -> adp + 1 inorganic phosphate + energy
184
coupling pumps means
transporting 2 molecules against the gradient at the same time
185
types of coupled transport
symport, antiport
186
example of a frequently used pump
sodium potassium pump
187
sodium potassium pump mechanics
3Na+ out of cell, 2K+ into cell - pump oscillates b/w conformational states
188
in a Na-K pump, which molecules move in/out of the cell
Na+ out of cell, K+ into cell
189
mvmt of ATP for a Na-K pump
atp split into adp + p (p stuck at pump) for Na+ to leave, K+ binding from outside triggers release of p which restores the original conformation
190
process of protein changing its conformation
phosphorylation
191
Na-K pump actual uses
nerve impulse conduction
192
2 types of bulk transport
endocytosis, exocytosis
193
bulk transport is used for
very large or very polar molecules - e.g. proteins, polysaccharides
194
3 types of endocytosis
phagocytosis, pinocytosis, receptor-mediated
195
process of endocytosis
cell engulfs extracellular fluid, folds into plasma membrane, pinched off inside, vesicle usu fuses w lysosome
196
pseudopod
extension of cell that wraps around particles
197
what is a phagosome
vacuole with food particles enclosed in it
198
what is a phagolysosome
phagosome fused with lysosome
199
why does the phagosome fuse with a lysosome
lysosome digests particles using hydrolytic enzymes
200
what happens after the lysosome has digested the food particles (in the phagolysosome)
indigestible material left in the vacuole (now called residual body) removed via exocytosis
201
what is a phagocyte
white blood cell specialized for protecting the body by ingesting foreign substances
202
purpose of phagocytosis
defense mechanism, form of feeeding
203
lysosome enzymes work best at what pH
pH of 5
204
how is lysosome pH maintained
pumping H+ into the lumen
205
why is lysosome pH different from cytosol pH
so that the enzymes do not break down the cell if they're released
206
pinocytosis
phagocytosis but liquid
207
what is a ligand
a molecule that binds to a receptor
208
where are receptor proteins usually found
clustered in coated pits
209
which proteins help form vesicles for endocytosis
coat proteins - help with pinching
210
what is receptor mediated endocytosis
intake of molecules that bind specifically to a receptor
211
process of receptor mediated endocytosis
ligand bind to receptor, membrane pinches, ligand splits from receptor, ligand fuse with lysosome
212
what is a coated vesicle
vesicle containing ligands, receptors and coat proteins
213
organelle involved in exocytosis
golgi body (or the vesicle is from endocytosis in which case no organelle is involved)
214
function of exocytosis (3 points)
secretion, recycling membrane proteins, restoring cell membrane - keeping SA of membrane constant
