foundation 1 Flashcards
1
Q
about what percent of the plasma membrane is lipids?
A
50
2
Q
how can facilitated diffusion take place through a membrane?
A
pores/channels (non gated)
gated channels
carriers (uniports)
3
Q
what are the 2 ways secondary active transport can take place?
A
co-transporters (symporters)-movement of solutes in same direction
counter-transporters (antiporters) movement of solutes in opposite direction.
4
Q
what are the 4 ways something can move through a membrane?
A
passive diffusion
facilitated diffusion
secondary active transport
primary active transport
5
Q
what is the driving force of passive diffusion?
A
electrochemical gradient
6
Q
how do uniporters work?
A
change conformation to move a solute through PM to other side.
7
Q
how do non gated channels work?
A
integral protein that provides direct access to the cell-like a pore.
8
Q
what are some examples of non gated channels?
A
porins in bacteria
mitochondrial porins
nuclear pore complex
aquaporins
9
Q
what are some stimuli that cause gated channels to open?
A
voltage
mechanical
ligand binding
10
Q
what are some examples of carrier proteins?
A
GLUT1-red blood cells
GLUT2-intestine
GLUT4-skeletal and cardiac muscles
11
Q
what does flux mean?
A
flow/movement
12
Q
what is an example of a symporter/cotransporter?
A
Na+/glucose transporter (SGLT)
13
Q
what is an example of an antiporter/counter transporter?
A
NHE (Na+/H+-sodium proton exchanger)-important for maintaining cytosolic pH.
14
Q
what are the 4 main types of active transporter?
A
P-type ATPase
F ATPase
V-ATPase
ABC transporters
15
Q
what type of transporter is CTFR?
A
ABC active transporter
16
Q
how do active transporters work?
A
domain in transporter protein binds to atp-it hydrolyses-energy released used to create conformational change in in protein which moves solute against conc gradient.
17
Q
what is p glycoprotein?
A
an important active transporter which moves things out of cells.
18
Q
why is p glycoprotein important?
A
it’s overexpressed in cancer cells. has a wide range of substrates inc cancer drugs which leads to the drugs having no impact on cancer cells-big issue in multidrug resistant cancers.
19
Q
how does CTFR work?
A
it’s an active transporter but it uses atp to open a channel and then chloride ions move down their conc gradient.
20
Q
what happens in the Na+/K+ pump?
A
3Na+ out
2K+ in
(high K+ in the cell and high Na+ outside)
21
Q
what is ICF?
A
intracellular fluid-the fluid inside cells.
22
Q
what is ECF and its components?
A
extracellular fluid-fluid outside cells:
plasma volume
interstitial fluid
transcellular fluid
23
Q
what is plasma volume?
A
fluid not in cells in the blood present in the intravascular compartment.
24
Q
what is the intravascular compartment?
A
cardiac chambers+blood vessels
25
what is interstitial fluid?
fluid that bathes non blood cells of the body outside intravascular compt.
26
and is transcellular fluid?
ECF trapped in space surrounded by epithelial cells.
27
what is the total body water?
40L-60% of weight
28
what is the ECF volume in the body?
15L-20% of body weight
29
what is the ICF volume in the body?
25L-40% of body weight
30
what is the interstitial fluid volume in the body?
12L-80% of ECF weight (16% of total)
31
what is the plasma volume in the body?
3L-20% of ECF weight (4% of total)
32
what are the main solutes in the blood and interstitial fluid?
Na+, followed by Cl-. much lower-HCO3-.
33
what are the main solutes in the intracellular compt?
K+. followed by organic phosphate. also Mg2+ present but much lower.
34
what is organic phosphate?
an organic compound w a phosphate group attached.
35
what is cystic fibrosis caused by?
absence or error on the membrane channel CTFR.
36
what is ASL?
airway surface liquid-thin layer of watery solution that lies between airway epithelium and gas in lumen of airway.
37
what percent of mucus is water?
95%
38
what is mucus secreted by?
goblet cells and sub mucosal cells.
39
what happens in the airways of someone w cystic fibrosis?
ASL and mucus become dehydrated-mucociliary pathway stops-mucus continues to be secreted and thick layers build up+particles and bacteria collect.
40
what are some examples of proteins synthesised from free ribosomes in the cytosol?
cytosolic proteins
mitochondrial proteins
nuclear proteins
peroxisomal proteins
41
how to ribosomes know to get to the endoplasmic reticulum?
directed by an N terminal ER signal sequence-specific sequence of amino acids on the protein which directs it there.
42
what is protein translocation in cells?
when proteins move between cellular compartments.
43
what is a residue?
refers to a specific monomer within the polymeric chain.
44
how are proteins transported from the rer to the golgi and other organelles?
vesicular transport (in vesicles)
45
what's it called when part of the membrane breaks off to form a vesicle?
budding.
46
what is the process of forming vesicles controlled by?
vesicle proteins present on the organelle membrane.
47
what are 3 coated vesicle proteins?
COP1 (coat protein 1)-from golgi
COP11-er to golgi
clathrin-all around the place rly
48
what do chaperone proteins do in the rer?
help proteins fold properly then drop off when they're done.
49
what are the chaperone proteins that help CTFR fold?
calnexin
HSP70
HSP90
50
what happens to a misfolded CTFR?
chaperones stay attached
| ER recognises something is wrong-protein undergoes biosynthetic arrest (gets degraded)
51
what mutation causes CF?
there are bareee (1900) recognised mutations but most common one is ΔF508-deletion of phenylalanine residue at position 508.
52
what is the basic empirical formula of carbohydrates?
(CH20)n
53
what are carbohydrates consisting of 2-10 sugars called?
oligosaccharides.
54
what is a monosaccharide?
sugar that cannot be hydrolysed to give a simpler sugar.
55
what is a monosaccharide with 3 carbons called, and an example of one?
triose, eg glyceraldehyde
56
what is a monosaccharide with 4 carbons called, and an example of one??
tetrose, eg erythrose
57
what is a monosaccharide with 5 carbons called, and an example of one???
pentose, eg ribose
58
what is a monosaccharide with 6 carbons called, and an example of one???
hexose, eg glucose
59
what is a sugar with an aldehyde group called?
aldose
60
what is a sugar with a ketone group called?
ketose
61
what is lactose made of?
galactose+glucose
62
what's sucrose made of
glucose and fructose
63
what's maltose made of?
glucose and glucose
64
what's maltose the product of?
starch breakdown.
65
what breaks down starch in plants?
amylase
66
what bonds does glycogen have?
mainly a1-4-about every 7-11th glucose theres an a1-6 which forms a branch.
67
what are the major storage sites of glycogen in humans?
```
liver (20%)
skeletal muscle (80%)
```
68
what are the 3 classes of glycoproteins?
simple (mainly protein)
mucins (mainly carb-components of mucus)
proteoglycans (mainly carb)
69
what is an example of a structural glycoprotein?
collagen
70
what is an example of a hormonal glycoprotein?
erythropoietin (hormone kidneys produce to stimulate production and maintenance of red blood cells)
71
what is the role of mucus?
forms a protective layer on epithelial surfaces.
72
where is mucus found and what does it do there?
airways-traps pathogens
digestive tract-lubricates and protects stomach lining from acid
reproductive-cervical mucus prevents infection.
73
what are the 2 types pf glycosilisation?
N and O. N is when the sugar attaches to a nitrogen and O to an oxygen of a protein.
74
what is an o-glycan?
the sugar group that gets attached to the o of a protein in glycosilisation.
75
what is the function of simple squamous epithelium?
absorption, filtration, minimal barrier to diffusion.
76
what are the locations of simple squamous epithelium?
capillaries, alveoli, abdominal and pleural cavities.
77
what is the pleural cavity?
fluid filled space that surrounds the lungs.
78
what is the function of simple cuboidal epithelium?
secretion, transportation
79
what are the locations of simple cuboidal epithelium?
glands and ducts, kidney tubules, covering of ovary.
80
what are the functions of simple columnar epithelium and where is it found?
absorption, protection, secretion-digestive tract.
81
what are the 2 different types of stratified squamous epithelium?
keratinised
| non keratinised
82
what is the function and location of stratified squamous epithelum?
protection-skin, mouth, upper throat, oesophagus.
83
what is the function and location of pseudostratified columnar epithelium?
absorption and protection-has cilia. upper respiratory tract, trachea.
84
what is the function and location of transitional epithelium?
stretchable layer-bladder.
85
what is desquamation?
shedding of the outermost membrane or layer of a tissue, eg the skin
86
what is cell polarity?
the intrinsic asymmetry observed in cells, either in their shape, structure, or organization of cellular components.
87
how is cell polarity maintained?
transcytosis- vesicles carry membrane proteins to correct place on plasma membrane
tight junctions-act as fences against transmembrane diffusion.
88
what are tight junctions?
a network of proteins that seal 2 adjacent cells together.
89
how do you stain nuclei?
haematoxylin- stains them blue/purple.
90
how do you stain the cytoplasm?
eosin-stains it pink.
91
what is the golgi stain?
a method using silver nitrate to densely stain an entire single neuron.
92
what are the functions of cilia vs microvilli?
cilia: move mucus and remove debris and microorganisms. NOT increase SA.
microvilli: increase SA
93
what are the 3 major salivary glands?
parotid
submandibular
sublingual
94
what is a venule?
a small blood vessel in the microcirculation that allows deoxygenated blood to return from capillary beds to veins.
95
what are fibrocytes?
cells that circulate in the blood and produce connective tissue proteins such as vimentin and collagens I and III.
96
what is the apical region of a cell?
the region of a polarized cell that forms a tip or is distal to a base.
97
what do most amino acid sequences start with?
M for methionine.
98
what is the crystal structure of a protein?
the 3D structure.
99
what does CTFR stand for?
Cystic Fibrosis Transmembrane conductance Regulator
100
on what cells is CTFR present?
only present in the specific outside cells which line the epithelial tract-ie the apical cells.
101
what is the secretory pathway?
path of secretory proteins to cell membrane where they can be released.
102
what is the entry point of proteins into the secretory pathway?
RER
103
what is the SER the site of?
lipid and lipid membrane biosynthesis.
104
what type of proteins are translated using free ribosomes (that never go to the RER?)
ones that are used inside the cell.
105
what is the relative concentration of Na+ in the plasma, interstitial fluid (ISF) and intracellular fluid (ICF)?
a lot in the plasma and interstitial fluid and barely any in the intracellular.
(142, 145, 15mM)
106
what is the relative concentration of K+ in the plasma, ISF, and ICF?
a lot in the intracellular fluid and barely any int the plasma or interstitial. (4.5 vs 120mM)
107
what is the relative concentration of Cl- in the plasma, interstitial fluid, and intracellular fluid?
a lot in the plasma and more in the interstitial but a lot less in the cells.
(102, 116, 20mM)
108
what is the relative concentration of protein in the plasma, ISF, and ICF?
the ISF has no protein. the intracellular fluid has by far the most (4mM) followed by the plasma (1).
109
what is the osmolality of the different fluid compartments of the body?
ALL 290mOsm-said to be in equilibrium. if not, water will move to make them all equal.
110
what are the prefixes describing very tinyyyyy things
```
milli-10-3
micro-10-6
nano-10-9
pico-10-12
femto-10-15
```
111
what is a litre in terms of dm3?
ONE.
112
what is osmotic pressure?
pressure exerted by flow of water across membrane as determined by solute concentrations.
(increased=more water wants to come in)
113
what does low osmolarity mean?
hypo-osmolar solution-less solutes-lower osmotic pressure
114
what does high osmolarity mean?
hyper-osmolar solution-more solutes-higher osmotic pressure.
115
what's it called when the 2 solutions have the same osmolarity?
iso-osmolar.
116
what is tonicity?
conc of solution compared to another one-measure of effect solution has on cells placed in it.
low tonicity=low osmolarity (low conc)
117
what is a hypotonic solution?
when the osmolarity of the solution is less than intracellular.
118
what do adhesion proteins do in a cell?
attach cytoskeleton to cell membrane.
119
what are the 3 major lipids in the cell membrane?
phospholipids
sphingolipids
sterols (cholesterol)
120
what are the 3 most abundant phosphoglycerides?
phosphatidylethanolamine
phosphatidylserine
phosphatidylcholine
121
what are the functions of chromosomes?
tight packaging of DNA
| allow DNA to be accurately distributed between ells during cell division.
122
what is the major and minor premise?
major premise: main point. minor premise: something that logically follows that point.
123
what is missfolded CFTR degraded by?
the PROTEASOME. NOT the lysosome.
124
what is the site of mRNA processing in eukaryotic cells apparently?
the nucleus.
