WEEK 1: Plasma Membrane pt 1 Flashcards
EXAM 1 (63 cards)
1
Q
5 questions to ask while studying
A
what is it?
who makes it?
what does it do?
what stimulates it?
what inhibits it?
2
Q
Cell membrane functions
A
- protects the cell
- semi-permeable (passive/active transport)
- maintain concentration
- allows cell recognition/communication
- allows receptivity
- allows the cell to maintain its shape
3
Q
Additions to phospholipid bilayer
A
- cholesterol
- proteins
- glycoproteins, proteoglycans, glycolipids
4
Q
Cholesterol - what does it do in the cell membrane?
A
inserts between phospholipids & contributes to rigidity
5
Q
2 types of proteins that contribute in transferring molecules in the cell membrane
A
integral & peripheral
6
Q
3 types of carbohydrates that face the exterior
A
- glycoproteins
- proteoglycans
- glycolipids
7
Q
Glycoproteins
A
short branched saccharide (sugar) chain on protein
8
Q
Proteoglycan
A
long unbranched saccharide (sugar) chain on protein
9
Q
Glycolipids
A
-lipids with a carbohydrate attached
10
Q
What is a carbohydrate
A
sugar molecule
11
Q
what is a residue?
A
- specific monomer within a polymeric chain
4 types of monomers
sugars, amino acids, fatty acids, and nucleotides
12
Q
Glucose formula
A
Monomer C6 H12 O6
13
Q
Phospholipid structure consist of
A
- glycerol
- 2 fatty acids
- phosphate group
14
Q
Glycerol
A
C3 H8 O3
- naturally occurring alcohol
- 3 - carbon polyalcohol acting as a backbone for phospholipid
15
Q
Fatty Acid
A
- attached to glycerol
- building block of fat and in food we eat
STRUCTURE
- a carboxylic acid consisting of a hydrocarbon chain
- a terminal carboxyl group
General formula
CH3(CH2)nCOOH
16
Q
Phosphate group
A
PO4 -3
attached to glycerol
- a phosphorus atom bound to four oxygen atoms
17
Q
Phospholipids
A
lipid containing a phosphate group in its molecule
18
Q
Hydrophobic
A
- fear of water
- tail of phospholipid containing
- fatty acids (non polar) chains of carbon and hydrogens
19
Q
Hydrophilic
A
- water loving
- Head of phospholipid
- phosphate group (polar)
20
Q
Is the phospholipid bilayer non spontaneous or spontaneous
A
partially hydrophilic & partially hydrophobic phospholipid = SPONTANEOUS bilayer
- the belayer can for by itself
21
Q
phospholipid bilayer - what bond holds them together
A
hydrogen bonding of water
22
Q
Different types of phospholipids
A
- phosphatidyl - choline
- phosphatidyl- ethanolamine
- phosphatidyl - serine
- phosphatidyl- inositol
23
Q
Why do different types of cells have different phospholipids?
A
- diff cells have diff concentrations so they need diff phospholipids to regulate
24
Q
Within a phospholipid, what distinguishes the different types?
A
- R group determines phos group
(organic compound)
25
2 types of fatty acids
- saturated fatty acid
- unsaturated fatty acid
26
saturated fatty acid
All single bonds, saturated with H bonds
27
unsaturated fatty acid
double bonds (not saturated with H bonds)
- kinks, loosely packed
28
Benefits of adding unsaturated fatty acids
- membrane fluidity due to kinks
- looser packing of phospholipids
29
Membrane proteins functions (6)
1. transporter
2. enzymes
3. cell surface receptors
4. cell surface identity marker
5. cell-to-cell adhesion proteins
6. attachments to cytoskeleton
30
T or F: All enzymes are protein
True
31
T or F: All proteins are enzymes
False
Proteins aka
- enzymes
- polypeptide
- amino acid
32
Peripheral membrane proteins
- anchored to a phospholipid in one layer of membrane
- free to move throughout one layer of the bilayer
- they help to transport non polar compounds to various locations in the cell, signaling, and maintaining the cell shape and structure
33
integral membrane proteins aka (?)
Transmembrane proteins
- span the lipid bilayer (both halves)
(transmembrane domain)
- non polar region of (imp) embedded in interior
&
- polar region of (imp) protruding from both sides
34
What do integral proteins contain
hydrophobic amino acids
35
What is created with extensive non polar region within a transmembrane (imp)
a pore through the membrane
36
What is a pore called in a transmembrane protein region
B-barrel
- B-sheets in protein secondary structure form a cylinder
AKA - Beta pleated sheets
37
B-barrel (beta pleated sheets) are polar or non polar
polar - allows water and small polar molecules to pass through membrane
38
2 things required to make anything move in the body
1. gradient (concentration, electrical, pressure)
2. permeability
39
What do ions need if they can't dross the membrane their own?
protein to gate membrane permeability
40
What mediates membrane permeability?
- channel protein
- carrier protein
41
2 types of membrane transport
- passive transport
- active transport
42
Passive transport
- No ATP is needed at the membrane
- small particles cross membrane through special proteins or lipid bilayer
43
Active transport
- ATP is NEEDED at the membrane
- proteins are used as pumps to move substances against their concentration
44
ATP
Adenosine - triphosphate
- the source of energy for use and storage at the cellular level
45
what direction does gradient move
HIGH ---> low
46
Simple diffusion
the process small molecules, atoms, or ions diffuse through a semipermeable membrane down their concentration gradient without the assistance of transporter proteins
HIGH ---> low
47
Molecules that move through simple diffusion
O2
H2O
Urea
Glycerol
CO2
48
What is needed when substance needs to be pumped out of the cell
Using ATO to pump substance against its gradient
ENERGY - ATP (work)
called Active Transport
49
Facilitated Diffusion (passive transport)
- Selective permeability
- intergal mem pro allow cell to be selective about what passes through
- carrier protein
- channel protein
50
What travels through facilitated diffusion?
Charged molecules (small) and large uncharged molecules
Na+, K+, glucose
51
Osmosis
diffusion of water across a selectively permeable membrane
-from HIGH --> low concentration of water
- movement of water from HIGH concentration to low concentration
52
Osmosis parts (passive transport)
Aqueous solution
Solvent - water
Solutes - dissolved substance
53
Osmotic solutions
3 different concentrations
- hypertonic: higher solute concentration
--- dunk solvent (cell) into high concentrations solute, cell will shrink bc water is leaving the cell to dilute hypertonic solution (solute with high concentration)
- hypotonic: lower solute concentration
---- dunk solvent (cell) into low concentration solute, cell will burst bc water will enter the cell to concentrate hypotonic solution (solute with low concentration )
- isotonic: same concentration
--- no effect
54
Active transport: what it requires and 2 types
- primary active transport
- secondary active transport
- moving against gradient
- requires the use of carrier protein
-uniporters: move one molecule at a time
- symporters - move two molecules in the same direction
-antiporter: moves 2 molecules in opposite direction (cotransporters)
55
Primary active transport
moving substance from low --> HIGH concentration
56
What kind of transporter is sodium potassium pump
primary active transporter
57
Primary Active transporter =
Sodium potassium ATPACE
58
What does the word "PUMP' mean
pushing something against its gradient
59
Steps of sodium potassium pump
1. Starts with Integral mpro (carrier medicated)
- binds 3 intracellular Sodium
2. Phosphorylation: use ATP at the membrane to break one of the phosphates off the protein to phosphorylate it into ADP
3. Carrier protein changes shapes to release sodium out of the cell (3 sodiums out)
4. 2 Potassiums get pulled into the carrier protein
5. Dephosphorylation: phosphate leaves protein carrier after potassium sticks
6. Changes back to original conformation to start the process over again due to dephosphorylation
60
Name of outside and inside the cell
intracellular
extracellular
61
Phosphorylation
phosphate molecule sticking onto protein
62
Thyroid hormone is
Fatty; lipophilic
- receptor is within the cell goes into the nucleus
can move right through membrane
63
