UNIT 3 lecture notes Flashcards
1
Q
Cells
A
range from 10-140 microns in diameter but usually 5-10 because cells have more volume than surface area
some have no nuclei and some have 100s
2
Q
squamous cells
A
flat on the bottom and blobs on top
3
Q
cuboidal cells
A
squares (cubes)
4
Q
columnar cells
A
rectangles
5
Q
Organelles with a membrane
A
Nucleus MItochondria Golgi apparatus Endoplasmic reticulum lysosomes peroxisomes
6
Q
organelles with no membrane
A
ribosomes, proteosomes, cytoskeleton, centrosome and centrioles, cilia
7
Q
eukaryotic cell
A
possess nucleus
8
Q
prokatyotic cell
A
lack nucleus (bacteria)
9
Q
extracellular fluid
A
interstitial fluid plasma (fluid of blood) cerebrospinal fluid ( fluid surrounding nervous system organs)
10
Q
extracellular- cellular secretions
A
(saliva and mucous)
11
Q
extracellular matrix
A
substance consisting of numerous proteins that acts as glue to hold cells together
12
Q
apical surface (epithelial)
A
top surface of cells
13
Q
basement or basal surface
A
bottom of cells held together by extracellular membrane (basement membrane)
14
Q
Function of plasma membrane structure (fluid mosaic model)
A
seperates two aqueous compartments and forms a selectively-permeable barrier
15
Q
Glycocalyx
A
carbohydrate coating that gives cells their identity (cell recognition)
16
Q
glycolipids
A
connected to plasma membrane
17
Q
glycoproteins
A
connected to integral proteins
18
Q
Functions of the plasma membrane: mechanical/physical membrane
A
separates two of the body’s fluid compartments
19
Q
Functions of the plasma membrane: selective permeability
A
determines manner in which substances enter or exit the cell
20
Q
Functions of the plasma membrane: electrochemical gradient
A
generates and helps maintain the electrochemical gradient required for muscle and neuron function (the four main ions)
21
Q
Functions of the plasma membrane: communication
A
allows cell-to-cell recognition (IE: egg to sperm) and interaction
22
Q
Functions of the plasma membrane: cell signaling
A
plasma membrane proteins interact with specific chemical messengers and relay messages to the cell interior (not all chemical signaling)
23
Q
phospholipids are attracted to what
A
diglycerides
24
Q
glycolipids are attracted to what
A
triglyceride
25
Membrane lipids components and percentages
75% phospholipids (made of two parts)
5% glycolipids- lipids with sugar groups on outside of membrane surface)
20% cholesterol- increase membrane stability
26
Membrane proteins
```
Communication with environment
about 50% of the plasma membrane's mass
have specified membrane functions
free floating or tethered proteins
(integral and peripheral proteins)
```
27
peripheral proteins
connected to an integral protein or plasma membrane surface
28
Integral proteins
Embedded in plasma membrane or attached via covalent bonds
29
6 roles of membrane proteins
1. transport
2. receptors for signal transduction
3. attachment to the cytoskeleton and extracellular matrix
4. enzymatic activity
5. intercellular joining
6. cell to cell recognition
30
cell to cell attachments of bound cells through
plasma membrane proximity, the glycocalyx, tight junctions, desmosomes, gap junctions
31
Plasma membrane proximity
cells are so close they fit like puzzle pieces
intergral proteins on adjacent cells fuse
(claudins and occludins are common proteins)
32
glycocalyx
consists of sugars (carbohydrates) sticking out of cell surface
glycolipids and glycoproteins
Different patters for recognition
allows immune system to recognize self and nonself
33
Desmosomes
Consist of plaque (protein)
linker (transmembrane) proteins
intermediate filaments
Give attachment but reduce mechanical stress
34
gap junctions
connexons form tunnels allowing small molecules, ions, and simple sugars to pass from cell to cell
this allows electrical signals to be passed quickly from cell to cell
(cardiac and smooth muscle cells)
35
hydrophobic (nonpolar molecules) permeability
highly permeable to small, fat soluble (nonpolar) substances (O2, CO2)
GASES
36
small, uncharged, polar molecules permeability
less permeable to smaller polar molecules (WATER, urea)
37
large, uncharged, polar molecules permeability
even less permeable to large polar molecules (glucose) NEEDS GLUC TRANSPORTER
38
ions permeability
highly impermeable to ions, even though very small
| NEED SPECIFIC TRANSMEMBRANE PROTEIN
39
The two movements of molecules/ions
Passive and active transport
40
Passive transports two movements
Downhill
Simple diffusion- oxygen moves from vessels, metabolism causes waste (CO2) and then CO2 is exchanged
Facilitated diffusion- passive but a protein is needed to help move
41
Diffusion
passive movement of molecules (equilibrium will be reached)
downhill (high to low area transfer)
no energy used
42
Active transports two movements
uphill
Primary active transport
Secondary active transport
43
movement of macromolecules/large particles
vesicular transport (active transport)
44
two types of vesicular transport
endocytosis and exocytosis
45
Endocytosis
(pinocytosis, phagocytosis, receptor-mediated endocytosis
46
Osmosis (passive)
diffusion of water
47
Osmosis (passive)
diffusion of water
| water moves from low solute concentration to high solute concentration
48
facilitated diffusion limitations: saturation
limited number of available carriers
| Tm= transport maximum or maximum rate of transfer for a solute
49
facilitated diffusion limitations: stereospecificity
binding sites stereospecific
50
facilitated diffusion limitations: competetion
similar solutes may compete for binding site
51
Integral protein for facilitated diffusion: non-gated (leakage) channel
is always open and is also called a pore
52
Integral protein for facilitated diffusion: gated channel
is intermittently open and closed (neurotransmitters)
| controlled by electrical or chemical signals
53
Glucose transporters (GLUT)
a type of carrier for glucose (polar but to large for any channel)
54
what is a carrier protein
membrane protein that bind to a substance and bring it to the other side of a membrane
55
carrier mediated facilitated diffusion
preformed by integral proteins
| carry specific polar molecules too big for membrane channels (sugars and amino acids)
56
osmolarity
number of particles in solution per volume
57
isosmotic
two solutions have the same osmolarity
58
Hyperosmotic and hyposmotic
Hyperosmotic is the solution with the higher osmolarity
| Hyposmotic is the solution with the lower osmolarity
59
isotonic solution
no osmotic flow (normal cell)
60
hypotonic solution
osmotic flow of water into the cell (swelling and maybe ruptures)
61
hypertonic solution
osmotic flow of water out of cell (shriveled cell and crenated)
62
active transport
uphill
requires ATP
does not depend on concentration gradient
63
primary active transport
ATP is used directly to facilitate solute movement
64
Na+/K+ ATPase (pump)
plasma membrane of virtually all cells in the body
| 3 Na+ out of cell and 2 K+ into cell for 1 ATP
65
Ca2+ ATPase (pump)
Pump calcium out of cell
| Pump calcium into SR and ER from the cytosol
66
H+/K+ ATPase (H+ pump)
H+ out and K+ in
| lining of stomach, kidney tubules, intestine
67
Antiporter
pumps something into cell and something out simultaneously against their concentration gradients (Sodium-Potassium pump)
68
Secondary active transport
downhill movement of one solute dependent on its concentration gradient
coupled to a solute independent of concentration gradient
69
co-transport
symport
| both solutes move in same direction
70
counter transport
antiport solutes move in opposite directions
71
Secondary active transport example
As Na+ diffuses back across the membrane through a membrane co-transporter protein, it drives glucose against its concentration gradient (ATP was indirectly used for glucose transport)
72
Pinocytosis and phagocytosis
pino- Cell drinking (ingestion if fluid and solutes)
| phago- cell eating (ingestion of larger cells/bacteria)
73
process of phagocytosis
1 phagosome enters the pseudopodium
2 phagosome fuses with lysosome
3 exocytosis
74
vesicular transport: receptor-mediated endocytosis
1 ligends bind to receptors in plasma membrane
2 ligends area divets and waits for foody
3 once it has food it becomes an endosome (coated vesicle)
4 fuse with primary lysosomes making a secondary lysosome
5 ligends are removed and absorbed into cytoplasm
6 lysosome endosomal membranes seperate
7 endosome fuses with plasma membrane and the receptors are again available for ligend binding
75
exocytosis
Substances in secretory vesicles
v-SNARE protein finds and hooks to t-SNARE proteins on membrane
this docking process triggers exocytosis (hormones, mucus, cellular wastes)
76
process of exocytosis
1 membrane bound vesicle migrates to the plasma membrane
2 proteins at vesicle surface (v-SNARE) bind with t-SNAREs (plasma membrane proteins)
3 fuse membranes and pore opens up
4 vesicle contents are released to cell exterior
77
roles of plasma membrane receptors: contact signaling
cells that touch recognize eachother by their unique surface membrane receptors
78
roles of plasma membrane receptors: chemical signaling
interaction between receptors and ligends (chemical messengers) that cause changes in cellular activities
79
G protein coupled receptors (GPCR)
membrane receptors
| have 7 transmembrane alpha helisies (cross membrane 7 times)
80
3 subunits of g proteins
alpha, beta, and gamma
| theyre connected by lipid anchors
81
what do g proteins bind to?
GTP/GDP (guanicine tri/di phosphate)
82
confromational change of a g protein
GPCR will change its shape once a signaling molecule bonds to it, creating a chain of events (ligend= signaling molecule)
83
target proteins
enzymes that produce secondary messengers or ion channels that let ions be second messengers
84
6 steps of g protein
1. ligends bind to GPCR
2. GPCR goes conformational change
3. alpha subunit chnages gdp for gpd
4. alpha subunit disociates and regulates target proteins
5. target protein can relay second message signal'
6. GTP hydrolyzed to GDP (loses phosphate in hydrolosis
85
what is found on the outside of the nuclear envelope and on the inner membrane and what kind of layer is it
ribosomes
it is smooth
-it is a double phospholipid bilayer and the nuclear pores hold them together
86
what is able to pass through nuclear pores
100 nanometers and must have a nuclear localization signal (NLS) to go into the nucleus from the cytosol
87
what is the NLS made of
a stretch of amino acids on a protein
88
what is chromatin simply said
a single stand of dna in its natural state. lose and chillin
89
what is a ribosome made of? (and %)
60% RNA
| 40% protein
90
where are ribosomes found
cytosolic surface of rough ER membrane and free floating in the cytosol
91
what is the outer membrane of the mitochondria and is it permeable
phosopholipid bilayer and its permeable
92
what is the cristae in a mitochondria?
the foldy part of the inner membrane
93
what is found on the inner membrane of the mitochondria and is the inner membrane permeable?
the electron transport chain used for atp synthesis and no
94
where is the inner membrane space and matrix in the mitochondria found?
inner membrane space is between the two membranes and the matrix is inside the inner membrane (the swigly stuff)
95
how does a mitochondria split/grow
through simple fission and by creating its own DNA.
96
What are the functions of the endoplasmic reticulum?
protein, lipid, and carbs synthesis, and Ca2+ storage
97
what is the membrane and two types of the ER
Phospholipid bilayer and you have rough and smooth ER
98
what does the word reticular mean?
branch
99
what does the rough ER do?
protein synthesis, secretes proteins, proteins become integral proteins or go to 3 different places. does post transitional modifications of proteins
100
the 3 sites a protein can go from the Rough ER
1. ER
2. Golgi
3. Lysosomes
101
Smooth ER functions
synthesis proteins
metabolizes carbs
aids indetox of drugs and toxins
102
What is a simple way to see the Golgi apparatus?
a traffic director of proteins and lipids
103
what is the Golgi apparatus made of?
cistern sacs
104
what does the Golgi apparatus do with the proteins and lipids recieved from the ER
modify, concentrates, and packages proteins and lipids
105
what are the three steps involved with the Golgi apparatus
1. transport vesicles from ER fuse to the Golgi
2. proteins and lipids received are further modified
3. Determines which of the three pathways it takes next and packages it
106
what is the addition of sugars called in the Golgi apparatus
Glycosylation (HENCE: glycolipids and glycoproteins)
107
what are the three paths form the Golgi
1. exocytosis
2. delivery to plasma membrane
3. delivery to sites within the cell
108
what is a simple explanation of a lysosome?
a garbage disposal
109
what are some of the lysosomes funtions
1. digest molecules and substances
2. autophagy- digest cell or other cells
3. macrophages- englulf bacteria and viruses and bring them to lysosomes
110
What are some of the functions of a peroxisome
its oxidative enzymes can detoxify, breakdown fatty acids and lipids
111
where are peroxisomes mostly found
kidneys and liver
112
what are the three purposes of the cytoskeleton
1. structural support
2. movement
3. transport inside of cells
113
what are the two proteins in microtubules
alpha and beta tubulin
114
what are the two motor proteins that shuttle substances on the microtubules
Kinesin and dynein
115
where are microtubules found mostly
nerve cells theyre very common and centrosomes
116
what size are microtubules
25 nanometers
117
what are microtubules components of
spindle fibers, cilia, and flagella
118
what are microfilaments made of
actin proteins
119
what are the two main functions of microfilaments
strengthen cell surface and resist compression
120
size of microfilaments
7 nanometers
121
what are intermediate filaments made of
tetramer fibrils and theyre twisted together.
122
what do intermediate filaments do
attach to desmosome plaques and act as internal tension cables
123
what is a simple explanation of intermediate filaments
springs in a matress
124
what are the three main intermediate filaments
1. neurofilaments
2. keratin
3. desmin (skeletal muscle cells)
125
out of the microtubules, microfilaments, and intermediate filaments which are dynamic?
the two micro-'s
126
what are cilia and flagella made of and in what composition
microtubules and in a 9+2 composition
127
what are flagella and cilia
generate movement- either a tail like sperm, or a bunch of hairs almost like a sea urcheon.
128
what do the flagella and cilia grow from
basal body
129
what is a centriole and its composition
microtubles and is a 9+0 composition. remember its nine packets of three microtubules
130
what is the centrosome matrix
the microtubule organizing center, (two centrioles at a right angle)
131
what happens in the phase
well G means growth so there is massive energy gain and copy dna
132
in G1 if cells stop and go on hold what are they in
G0- basically a sleep phase if they dont pass the checkpoint`
133
what happens in the S stage
DNA replication
134
what happens in G2 stage
prepare for mitosis and last minute protein synthesis
135
what is the longest stage in interphase?
the S stage
136
what else, other than dna, is duplicated in s stage
proteins like histones
137
what nitrogenous bases belong together?
Adenine:thymine
Cytosone:Guanine
138
what are the bonds in dna that the ribosome break?
hydrogen bonds
139
how can you tell the leading and laggind strand apart?
lagging strand will have gaps (can only go 5'-3')
140
what is the kinetochore for?
microtubules use it to pull chromotids apart
141
what happens in mitosis: prophase
microtubules start to form (mitotic spindle)
142
what happens in mitosis: metaphase
chromatids align at the center
143
what happens in mitosis: anaphase
centromere splits to seperate sister chromatids and they move to oposite poles
144
what happens in mitosis: telophase
nuclear membranes form
| and things go back to normal
145
what happens in mitosis: cytokinesis
cleavge furrow forms and pinches off to form two cells
146
what do go signals look for at checkpoints
enough energy, enough volume to surface ratio and the chemicals needed
147
what do stop signals look for
availiability of space
148
what are cyclins and their function
regulatory proteins that start working at interphase
149
what are Cdks and their functions
enzymes that activate cyclins
150
central dogoma of biology order
DNA to mRNA to protein
151
what is a code/codon and what does it consist of
a group of 3 nucleotides and they are for an amino acid
152
Three types of rna
mRNA- messenger
rRNA- ribosomal
tRNA- transfer
153
in what three ways does DNA and RNA differ in the RNA standpoint
uracil is used instead of thymine
Ribose instead of deoxyribose
Single stranded
154
what is the function of tRNA
translates RNA
155
what is an anticodon
the opposite matching code created (3 long)
156
What is the start codon?
AUG
157
what is splicing and what does it accomplish
splicing uses spliceosomes to remove introns and keep exons
158
anticodon loop
where the anticodons for the mRNA are
159
what are the three steps of translation
1. initiation- find AUG
2. elongation- go till stop codon while making peptide bonds
3. termination
160
where are proteins fed from the ribosomes into?
the lumon (ER)
161
what can flag proteins for death?
ubiquitins
162
Proteasomes dissasemble what?
proteins tagged with ubiquitins
163
what is name for cell death/suicide?
apoptosis
164
what enzyme is in charge of cell suicide?
caspases
