PSL 310 Cell physiology slide deck- complete

PSL 310 exam 1

what is a composite cell

a spherical cell that represents all organelles a cell CAN have

what makes up the cells plasma membrane

98% lipid(bilayer) and 2% protein

where does the e face of a cell membrane face

out of the cell into interstitial fluid

where does the p face of a cell membrane face

faces the cytosol of the cell to the cytoplasm/ICF

how much of the membrane is lipid

98%

of the lipid how much is phospholipid in the membrane

75% of the lipid

of the lipid how much is cholesterol in the membrane

20% of the lipid

of the lipid in the membrane how much is glycolipid

5% of the lipid

phospholipids function

building block of the membrane

cholesterol function

membrane integrity

glycolipid function

identity markers, protection in the membrane

glycerophospholipid components

fatty acid, glycerol, phosphate group, polar group

glyceroglycolipid components

fatty acid, glycerol, carbohydrate

glycolipids and glycoproteins combine to make

membrane carbohydrates

what face of the cell are membrane carbohydrates located on

e face

membrane carbohydrates can act as identity markers due to being

displayed as antigens

what type of permeable is plasma membrane

selective

what does membrane transport require

a pathway and an energy source

how can membrane transport be passive

uses energy from a concentration gradient

how can membrane transport be active

using cellular energy like ATP

passive transport example simple diffusion

move small non polar molecules down their concentration gradient across a semipermeable membrane

facilitated diffusion

movement of ions and polar molecules across the cell membrane by membrane proteins with their concentration gradient

what is facilitated diffusion facilitated by

channel and carrier proteins

leak ion channel

ions can leak out across the membrane with a gradient

gated ion channel

requires a signaling molecule/ neurotransmitter binds to the receptor in order for the channel to become open

common ions to cross membrane

K+, Na+

classes of carrier proteins

uniport, support, and anti port

uniport carrier

one moleculel can cross the membrane rate with a concentration gradient

symport and anti port carriers are both

cotransport carriers

symport carrier

allows two molecules to cross the membrane int he same direction via carrier mediation ( a carrier protein helps molecules cross)

antiport carrier

passively transports two molecules in different directions across the membrane, using concentration gradients and not energy

voltage gates K+ channel

what can be considered cytoplasmic extension

cilia, pili, micro pili

where does half of a pheripheal protein face out of the membrane

p face

moiety membrane protein

part of the protein is outside of the membrane on p or e face

glycocalyx

carbohydrate sugar chain on the p face

where are proteins amino acids hydrophobic vs hydrophilic

hydrophilic outside of the membrane, hydrophobic inside of the membrane

cell adhesion membrane protein function

connect cells to each other

immune tolerance

cells that express similar sugars to keep macrophages from eating them

what are impacts on diffusion rates

size, distance, gradient dircetion, temperature, electrical force

osmosis

movement of water molecules down a concentration gradient (higher to lower osmotic potential) across a semipermeable membrane

if a solution has many dissolved solutes what is the osmotic potential

low

if a solution has few dissolved solutes what is the osmotic potential

high

if a solution has low h2o how many solutes would it have

high solutes

if a solution has high h2o how many solutes would it have

low solutes

water moves from osmotic potential to _ osmotic potential

high, low

tonicity

the movement of water across membranes based on osmotic potential

what happens to a cell in isotonic solution

the cell and solution have the same solute concentration so there is no net movement of water

what happens to a cell in hypotonic solution

the solution contains less solutes than the cell does, so the cell has lower osmotic potential meaning the cell will swell (lyse)

what happens to a cell in hypertonic solution

the solution contains more solute than the cell does, so the cell has higher osmotic potential meaning the cell will shrivel up(crenate)

what is an aquaporin

a water selective pore to transport water across membranes

what is a GLUT

glucose transporter

what is GLUT 1

a basal transporter in most cells

what is GLUT 4

an insulin sensitive glucose transporter

what is GLUT 2

a liver cell that gets glucose out of a cell

what type of GLUT does almost every cells contain

GLUT 1

what happens when there is an increase in GLUT 4 expression due to exercise?****

an increase in insulin?*******

what type is glucose transport via GLUTs an example of

passive transport, uni-port, facilitated diffusion

what happens when a myocyte takes in glucose

it converts the glucose into glucose g-phosphate and stores it as glycogen, creating a gradient with glucose coming in , but if it stays as glucose the osmotic potential will drop allowing water in

what is primary active transport

movement of ions/molecules against their concentration gradient across the cell membrane, using ATP and facilitated by a carrier protein

how many ATP does the sodium potassium pump use

1 ATP

how does the sodium potassium pump work

3 Na in for every 2K out

how much of the bodies ATP is used on the sodium potassium pump

1/3

Ca 2+ PUMP?**

what is secondary active transport

movement of ions and /or molecules against their concentration gradient across the cell membrane using the energy of a concentration and facilitated by a carrier protein

does secondary active transport use ATP

no

what is the sodium glucose transporter used for

getting glucose into the cells of the small intestine

SGLT

sodium glucose transporter

how does the SGLT work

uses potential energy from the sodium of the sodium potassium pump to allow glucose into the cell from the lumen, this goes against the glucoses concentration gradient.

why does glucose coupled with SGLT go against a concentration gradient

the glucose is taken from the lumen where there is not much glucose located

where is SGLT 1 located

in intestines

where is SGLT 2 located

in kidney

what mechanism is secondary active transport via the SGLT

symport

what does the pump leak model show

pumping ions out of the cell and allow them to leak back into the cell

what types of channels can Na come in

leak channel, ligand-gated, voltage gated, mechanically gated

what changes if the Na comes in a ligand gated channel

the membrane potential

what changes if the Na comes in a voltage gated channel

the action potential

what changes if the Na comes in a mechanical gated channel

the membrane potential can change

what are the 3 forms of endocytosis

pinocytosis, receptor-mediated, and phagocytosis

what does pinocytosis do

bring in large volumes of ISF

what does phagocytosis do

bring in large molecules

what does receptor mediated endocytosis do

bings in a highly specfic molecule

how does cholesterol get into our cells

via receptor mediated endocytosis

how does receptor mediated endocytosis allow cholesterol into our cells

cholesterol is surrounded by LDL, allowing the polar head groups to interact with plasma membrane bound LDL receptors, coating the LDL in a vesicle to bring LDL into the cell, the LDL is uncoated and fuses with an endosome, within the endoscope the LDL is budded from its transport vesicle and the cholesterol is released into the cell, the LDL receptor will then return to the plasma membrane

what happens when there is too much LDL

cholesterol can end up in the interstitial fluid, creating an immune reaction

what does exocytosis do

move things out of the cell

how are antibodies generated in the blood

phagocytosis and antigen presentation

what do phagocyte PACs do to the pathogen

engulf

how does an antigen produce antigenic fragments

absorb the pathogen and break it down

what will the ER produce that binds to antigens

MHC II

where does the MHC II display the antigenic fragments

the cellular membrane

is the inside or the outside of the cell more negative

inside

what is the transmembrane potential (TMP)

voltage difference -70 mV

if the ICF is more negative than the ISF does the cell have polarity

yes

can a polarized cell be depolarized

yes

what is the TMP when a cell is at rest

resting membrane potential(RMP)

what is RMP of a neuron

70mV

what is RMP of a muscle cell

85mV

what is a decrease in membrane potential

depolarization

what is an increase in membrane potential

hyper polarization