Cell physiology Flashcards
(111 cards)
1
Q
What is the cell membrane? Why is it essential?
A
plasma membrane, thin, flexible barrier that separates cell from environment and regulates what enters and leaves cell.
essential to cell homeostasis and maintaining stable internal conditions.
contains cholesterol, proteins, and carbohydrates
2
Q
What are the two layers of the phospholipid bilayer?
A
head with fatty acid tail attached through glycerol molecule.
head= hydrophilic, negative
tail= hydrocarbon, hydrophobic
3
Q
What does cholesterol do in the bilayer?
A
-small steroid lipid embedded in TAILS and helps build steroid hormones.
-helps break up interactions between hydrophobic tails and keep membrane fluid.
- adds rigidity
4
Q
what do proteins do in bilayer?
A
-can be embedded within membrane or attached to either surface
- can anchor cell to environment
- participate in cell signaling
-act as transport proteins to move materials across membrane
5
Q
what do carbohydrates do in bilayer?
A
- can be attached to lipid or proteins
- ONLY exist in extracellular surface
-help cell to cell or cell to environment adhesion and mvmt - allow intracellular communication
6
Q
what is amphipathic
A
both hydrophilic and hydophobic
7
Q
what is the fluid mosaic model?
A
model of cell membrane. describes how the membrane is fluid and flexible and made of many components.
8
Q
what is selective permeability
A
tight seal of membrane prevents hydrophilic molecules and large molecules from passing through membrane.
9
Q
what do transport proteins do?
A
regulate movement of water
10
Q
What is concentration gradient?
A
difference in substances concentration between two regions
11
Q
what is a zygote?
A
fertilized egg
-takes 24 hours upon fertilization for first round of mitosis to occur
-sperm can stay 4-6 days in penile tract
12
Q
A
24 hours–> 2 cell stage–>
13
Q
what is morula?
A
ball of cells
at morula stage = cells are totipotent
14
Q
what
A
after morula stage—> blastacist
15
Q
differentiation
A
where cells become slightly different
16
Q
what are the two cell types of blastocyst stage?
A
inner cell mass (fetust) and trophoblast cells (placenta) – differentiation is taking place. genes are getting turned on and off
-blastocyst stage used for IVF
17
Q
blastocyst stage —> ?
A
gastrula stage: inner cell mass becomes restricted into 3 subtypes
18
Q
3 subtypes of gastrula stage
A
ectoderm: skin and nervous system
mesoderm: middle (connective tissue, muscle, bones)
endoderm: GI tract and internal (anus to mouth)
19
Q
what is pluripotent?
A
cell fate more restriced
20
Q
endoderm
A
-cells will pinch in at top and will form tube all the way to top— how anus to mouth is formed
- GI and outcropping system like pancreas, lungs
21
Q
ectoderm
A
- nervous system (CNS and PNS)
- skin
- sensory organs ( eyes, ears, and mammary glands)
22
Q
mesoderm
A
- anything in middle
- connective tissue (bone, blood)
- reproductive systems
- circulatory system
- renal system
- muscle
23
Q
what is the correct order for developmental stages
A
- zygote
- morula
- blastocyst
- gastrula
24
Q
stratified squamous is found where?
A
mouth, rectal, skin cavities, and reproductive
25
where can twins develop during what stage?
blastula and morula stage
26
If twins have their own placenta what are they referred to as?
- monochorionic
- morula stage
- 2 placentas and 2 fetus
27
If identical twins share a placenta what are they called and where did split occur? ***
- blastocyst
- inner cell mass splits
28
phagocytosis
larger objects are absorbed by membrane and brought in
29
pinocytosis
fluid based
30
receptor-mediated endocytosis
- binding of substance or molecule
31
What can go through cell membrane easily
- hydrophobic
- gas (nonpolar)
- make anesthesia gas so it is easily absorbed
- cells produce a lot of CO2 waste must need to easily exit
- diffusible
- steroid hormones (estrogen, testosterone, cortisol, progesterone)
- small lipids
32
is water diffusible
not diffusible
33
aquaporins
water own transport mechanism
34
what needs to gain entry into cell
- water
- amino acids
- electrolytes
- fatty acids
- large molecules
35
diffusion
movement of particles passively from high to low
36
osmosis
movement of water
37
passive transport
high concentration ---> low concentration
- move passively no energy required
38
active transport
low concentration --> high concentration
- needs energy
- push ions up gradient
- uses ATP
39
If internal O2 concentration is 0.15 mol of cell. If cell is put in salt water with concentration of O2 is 1 M. Where will oxygen go?
oxygen will move into cell
- passive
- high to low
40
what directs osmotic movement of water
Na+ and glucose (sugars)
- water follow salt, sugars, and albumin (albumin protein in blood stream)
kidney: diuretics uses sodium. where sodium is pushed water will flush out.
diabetes: sugar goes into feet and stays and water will follow causing issues
41
what mode does CO2 exit cells
free passive transport
42
What mode of diffusion is osmosis
facilitated ---> goes through channel
passive osmosis
43
four forms of cell communication
steroid, ion or channel- linked, enzyme- linked, and g- protien
44
steroid diffusion ***
steroids are hydrophobic non polar ligand
- every hormone has specific binding site
- hormone binds to receptor protein
- hormone receptor complex
- complex opens up gene allows transcription and translation (steroid response element)
-
testosterone response elements (TRE)
45
ligands
stimulate cell communication, initiate process
46
water based ligands use what 3 pathways
ion or channel- linked
enzyme linked
g-protien linked
47
what do hormones do
made by one cell, expressed, and binds
48
Tamoxifen
too much estrogen bind to too many estrogen receptors can cause mitosis in cells
uncontrolled growth of cells leading to cancer.
- common tx is block ER receptors -- blocks gene activation
- bind to estrogen receptors and blocks binding site so estrogen cannot access it
49
Plasma membrane receprors
iochannel-linked (ligand-gated)
- acetylcholine receptors
50
Ion gated or channel linked recptors
- neurotransmitter binds to acetylcholine receptor or ion gated receptors
- binds
- protein changes shape so ions can go in and out of cell
-drugs can maintain channel to stay open longer (more serotonin for longer amount of time)
51
Enzyme or Catalytic Receptors
- enzyme (proteins with a job) (typically kinases) bound to intracellular side
- bind to receptors with inactive kinase
- causes change in shape
- when ligand binds, conformational change, causes them to move closer to each other, phosphorylation occurs, serve as docking sites for other proteins in turn becomes phosphorylated
- go into nucleus
- open up certain genes/ turn into genes
52
what does kinase do
- adds phosphates (on switch typically) to protein = phosphorylates
- higher energy status
53
G-protein activation
-G-protien coupled receptors have 7 transmembrane passages (how they are identified) (hydrophobic profile) , when ligand binds ---> recruits trimeric protein G protein (alpha, gamma, beta protein together) (exists in inactive state: GDP (guanosine diphosphate); active state (ligand has binded): GDP --> GTP(guanosine triphosphate) -- conformational change
- GTP - alpha subunit is activated and dissociates -- conformational change and now beta gamma complex
-regulate activity of protein in
activated g protein (GTP anlpha subunit):
1. causes ion channel to open causing sodium calcium and potassium to move in and out of cell
2. adenylate cyclase--> cAMP (2ndary messenger because activating intracellular pathway)--> protein kinase A (transcription factor) --> gene activation
Ex: glucagon
3. phospholipase C (activated) --> IP3 (2ndary messenger) ---> Ca release by sarcoplasmic reticulum
- covalently attached lipid tails that attaches them to bilayer (beta and gamma)
54
Adrenergic receptors
activated G protein coupled receptors that innervate the sympathetic nervous system
55
ligands for adrenergic recptors
catecholamines
1. epinephrine
2. norepinephrine
3. dopamine
56
adrenergic recptors
alpha 1: vasocontriction, smooth muscles in eye,
57
alpha 1 receptors cause
- more sympathetic (fight or flight) and less parasympathetic
- smooth muscle contraction
- increase BP
- eye dilation
- bladder sphincter contraction ( pee)
58
alpha 2 receptors cause
- parasympathetic
- pre synaptic neurons
- inhibits norepinephrine
- decrease norepinephrine release
59
beta blockers
prevent fight or flight
60
beta 1 recptor
- heart and juxtaglomerular kidney cells
- increase BP
61
juxtaglomerular kidney cells
- produce renin (fluid retention)
- right before glomerulus
62
Beta receptors
prefer epinephrine
dilation
cand bind norepinephrine also but not preferred
63
beta 2 receptors
bronchiole smooth muscle --> bronchodilation
- high dose of epinephrine stimulates bronchioles ot open
- ciliary body of eyes -- can be used to decrease eye pressure
- skeletal muscle--> increase innervation
64
cholinergic recptors
bind acetylcholine
1. muscarinic
2. nictinic
65
what are fibroblasts
cells that create Extracellular matrix
66
what is the extra cellular matrix?
meshwork of fibrous proteins embedded in a gel-like substance composed of complex carbohydrates. allows for rapid diffusion of nutrients, metabolites, and hormones betweet blood and tissue cells
67
What are fibrous proteins
collagen (very abundant, allow elasticity, plays part in scar formation)
elastin
fibronectin
laminin
68
What are cytoskeletal proteins?
microfilaments- alpha and beta actin are primary proteins
intermediate filaments- keratin
microtubules- largest, form spindle during mitosis and meiosis. Cancer- tubulins to block spindle formation
69
Microtubules are part of what? and do what?
- major component of cytoskeleton
- form highway system --> help move stuff around cell
- form flagellum and cilia
- motor proteins move along microtubules toward cell membrane
- in all cells
70
What do microfilaments do?
actin microfilaments aide in cell movement by being structural force. go to positive end
71
common intermediate filament?
keratin
72
Unsaturated Fatty acids
L- liquid at room temp
U- unsaturated
V- vegetables and produced by fish
D- double bond
73
Saturated fatty acids
opposite from unsaturated
- dense or solid at room temp
- produced by animals
74
What is hypercholesterolemia?
- typically males
- genetic, cannot absorb cholesterol/ lack receptors for cholesterol. levels will be high since cells cannot absorb
- estrogen protects against high LDL
75
Cell adhesion molecules ( CAMs). What are the four types?
cell surface receptors that anchor cells to one another or the ECM
1. Cadherins (calcium dependent)
2. Integrins (calcium dependent
3. Selectins
4. IgSF CAMS (immunoglobulin superfamily
76
types of passive transport?
- simple diffusion
- facilitated diffusion
- osmosis
77
simple diffusion
does not rely on membrane proteins
78
facilitated diffusion
mediated transport of molecules across the membrane through channels or carrier proteins. Allows hydrophilic (polar)
79
simple columnar epithelium (digestive tract)
80
simple columnar microvilli (small intestine)
81
startified squamous , non keratinized (oral, vaginal, anus
82
stratified keratinized squamous
83
transitional epithelium
84
pseudostratified columnar ciliated
85
what are the three muscle types
skeletal , cardiac , smooth
86
epithelial simple cuboidal - ducts
87
epithelial simple columnar (digestive system like stomach, intestinal tract, gall bladder)
88
epithelial simple squamous ( alveoli)
89
transitional epithelium bladder
90
pseudostratified ciliated columnar (trachea and bronchi)
91
keratinized stratified squamous
92
simple columnar with microvili (small intestine)
93
skeletal muscle
94
skeletal muscle
95
cardiac muscle
96
smooth muscle
97
neural tissue
98
connective adipose tissue
99
What is A and B? What is 1,2,3?
A= vein B= artery
3= tunica interna
2= tunica media
1= tunica externa
100
alveoli, bowmans capsule, arterioles, venules
simple squamous
101
ducts (kidney and glands)
simple cuboidal
102
digestive system, gall bladder
simple columnar
103
small intestine
simple columnar microvilli
104
vaginal, oral, anal
stratified squamous non-keratinized
105
epidermis - which cell types?
stratified squamous keratinized
106
domed shape cells, bladder
transitional
107
trachea, bronchi
pseudostratified columnar w cilia
108
striated, nuclei in periphery, gap junctions
skeletal muscle
109
nuclei in center of cells, gap junctions, some striation
cardiac muscle
110
no striations, nuclei in center, cigar shaped
smooth muscle
111
