Anatomy and Phys Lecture 5

What is the primary biomolecule of the membrane

lipids

Function of acylglycerol

long-term energy storage

Function of phospholipids

primary component of lipid membranes

function of steroids

chemical messenger + structural component

function of wax

protective barrier

Saturated fatty acids have a ______ tail

straight

Unsaturated fatty acids have a _____ tail

bent

head of lipids are

hydrophillic

tail of lipids are

hydrophobic

polar head groups exposed to aqueous exterior environments, nonpolar tails sandwich in the center

phospholipids

can be transmembrane or peripheral

proteins

hydrocarbon ring structure integrates with phospholipid fatty acid tails, hydroxyl group aligns with phospholipid polar head groups

cholesterol

small nonpolar solutes (oxygen, CO2, steroids)

permeable

large, polar solutes (carbohydrates, proteins, charged ions)

impermeable

movement down the concentration gradient

passive transport

movement against concentration gradient

active transport

direct movement of a solute across the semi-permeable membrane

simple diffusion

movement of impermeable solutes using transport proteins

facilitated diffusion

serves as a pore permits flow of solutes

channel protein

binds solutes and chaperones them across membrane

carrier protein

types of channel proteins

voltage-gated, ligand-gated, mechanosensitive

transport of molecules against a concentration gradient

primary active transport

carrier protein that performs active transport

sodium-potassium pump

proton pump

channel protein that performs active transport

___________ use ATP indirectly to perform active transport

Co-transporters

the ability of a cell to send and receive electrical signals across the plasma membrane

excitability

difference in concentration of a substance between two compartments

concentration gradient

transport ions across a membrane

ion channels

types of transmembrane proteins

gating, ion selectivity

in a healthy person, the relative concentration of any one ion is _______

constant

when permeability of an ion increases...

resting membrane potential moves towards that ion's equilibrium potential

when permeability of an ion decreases...

resting membrane potential moves away from that ion's equilibrium potential

a membrane potential exists across the cell membrane because the cytosol and the extracellular fluid differ in their _________

ionic composition

detects a stimulus and transduces it into an electrical signal

neuron

projections that extrude from the cell body

dendrites

long process extruding from soma, where action potential travels

axon

distal portion of the axon, site of signal output

axon terminal

cell body, contains nucleus, organelles and majority of cytoplasm

soma

'trigger zone' where action potential is generated

axon hillock

neurons relay messages through _______

synapses

neuron located before a synapse, sends the signal

pre-synaptic cell

gap between two cells filled with interstitial fluid

synaptic cleft

neuron located after a synapse, receives the signal

post-synaptic cell

which part of the neuron transmits the electrical signal from one end of the cell to the other

axon

ligands released from presynaptic cell produces __________ in post-synaptic cells

graded potentials

graded potentials __________ in amplitude with stimulus strength

increase

graded potentials occur at the ________

dendrite

graded potentials in dendrites are called _________

synaptic potentials

excitatory post synaptic potential

depolarizing

inhibitory post synaptic potential

repolarizing

an excitatory post synaptic potential is

depolarizing

an electrical impulse in a neuron

action potential