Phospholipids differ in.txt

Phospholipids differ in

Two important factors in membrane fluidity

lack hydrophobic groups and are not embedded in the bilayer

are partly embedded in the phospholipid bilayer

extends through the bilayer on both sides and may have different function in its external and transmembrane domains

plasma membrane carbs are located on the ____ membrane. they can serve as ___.

A carb bonded to a lipid

a carb bonded to a protein

thsi type of transport does NOT require metabolic energy

this type of transport DOES require metabolic energy

types of passive transport

diffusion through the phospholipid bilayer

diffusion through channel proteins r aided by carrier proteins

speed of diffusion depends on these 3 factors

____ molecules do not pass through the bilayer. they are not soluble

diffusion of water across membranes

during _________ water passes through special membrane channels

this kind of solution has a higher solute concentration

this kind of solutions have equal solute concentrations

these kinds of solution has a lower concentration

the internal pressure against the cell wall. preventing water from entering as it builds up

two ways of facilitated diffusion

this is a type of channel protein- most are gated. and can be opened or closed to ion passage

this opens when a stimulus caused the channel to change shape

a chemical signal

a ____ gated channel responds to its ligand

a ______ gated chanenel opens or closes in response to a change in the voltage across the membrane

water crosses membranes at faster rate than ______ diffusion

water may ______ with ions such as Na+ as they pass through ion channels

the faciliated diffusion sysetm can become _____ when all of the carrier molecules are bound and the rate of diffusion reaches its max

______ transport requires the input of energy to move substances against their concentration gradient.

______ transport is used to overcome concentration imbalances that are maintained by proteins in the membrane

the energy source for active transport

active transport is _____ and moves a substance against its concentration gradient.

a substance moves in the durection of the ______

types of active transport

this kind of acive transport involves hydrolysis of atp for energy

this kind of active transport used the energy from an ion concentration gradient, or an electrical gradient

this is an important membrane protein that pumps sodium OUT of the cell and K in

one molecule of ATP moves ___ K and ____ na ions

______ active transport used energy that is regained

secondary acive transport may begin with ______ of a few ions, or may involve ______ that transports both a substance and ions

macromolecules are too big or too charged to pass through membranes, instead, they pass through

To take up or secrete macromolecules, cells must use

3 types of endocytocis (brings into cell)

during _____, the membrane invaginates the molecules and forms a vesicle that separates fom the membrane

during ____, part of the membrane engulfs a large particle of a cell

during _____, (cellular drinking), small vessicles form, bring in fluids/dissolved substances

receptor mediated endocytosis depend on _____ to bind specific molecules (their ligands)

receptors are important membrane proteins locaed in

cytoplasmic surace is coated by another protein

when receptors bind to their ligands, the coated pit ____ and forms a _________

The clarhrin stabilizes the vesicle as it carries the _____ into the cyttoplasm

Once inside, the vesicle loses its _____ and the substance is digested

this process moves the materials out of the cell in vesicles

in exocytosis, the vesicle membrane fuses with the ___________ and the contents are released into the cellular environment

these kinds of signals affect the same cell that released them

these kinds of signals diffuse to and affect NEARBY cells

these kinds of signals travel to distant cells

only cells with thte necessary receptors can respond to a signal. the ___ cell must be able to sense it and respond to it

a signal transduction pathway involves a ___, a ____ , and a _____.

during _______ regulation, a signal molecule (ligand), fits into a three dimensional site on the receptor protein, causes it to change shape, and produces either a short or long term response.

_______ receptors have ligands, such as estrogen, that are small or non polar and can diffuse across the membrane

______ receptors have large or polar ligands, such as insulin, that CANNOT diffuse and must bind toa transmembrane receptor at an extracellular site.

_____ ____ ______, also known as GATED ___ _____ , change their three dimensional shape when a ligand bonds.

___________ receptors change their shape when a ligand binds

protein kinase catalyze the pholowing reaction:

ligands binding to a ______ expose a site than can bind to a membrane protein (a _______ protein).

the ______ protein is partially inserted in the lipid bilayer and parially exposed on the cytoplasmic surface

3 subunits of g proteins

The g protein-linked receptor changes a GDP nucletide bound to the g protein for a higher enrgy

signaling can initiate a ______ of protein interactions; the signal can then be ____ and_____ to cause different responses

a _____ messenger is an intermediary between the receptor and the cascade of responses.

in fight or flight response, epinephrine activates the liver enzyme _______ __________.

______ enzyme can be activated by the membrane bound epinephrine in broken cells as long as parts are present.

the molecule that delivers the messege from the 'first messenger', epinephrine to the enzyme.

in protein kinase pathway, ______ binds to its receptor and activates a G protein

cAMP is produced and activates _________-it phosphorylates two other enzimes with opposite effects ____ & ______.

During _____, protein kinase A inactivates glycogen synthase through phosphorylation and prevents gluclose storage

During ____ phosphorylase kinase is activated when phosphorylated and is part of a cascade that results in the liberation of glucose molecules.

Signal trasductione ends when

2 ways cells can alter the balance of enzymes

3 ways cell function changes in response to environmental signals

What effect does caffeine have on the brain?