Chapter 7-Packet

Describe how phospholipids with unsaturated hydrocarbon chains affect membrane fluidity?

__: resisting changes in membrane fluidity that can be caused by temp. change

What are the types of membrane protiens? (6)

__:
channel: a protien that spans the membrane may provide a hydrophilic channel across the membrane that's selective for a particular solute;
carrier: shuttles substances from one side to the other by changing shape- hydrolyze ATP as energy source
- facilitative diffusion is a part of this

__: a protein built into membranes may be an enzyme with its active site exposed to substances in the adjacent solution. In some cases, several enzymes in a membrane are organized as a team that carries out sequential steps of a metabolic pathway.

__: membrane protein may have binding site with specific shape that fits shape of chemical messenger- like a hormone. External messenger may cause a shape change in the protein that relays teh message to the inside of the cell, usually by binding to the cytoplasmic protein

__: some glyco-proteins serve as identification tags that are specifically recognized by membrane proteiins of other cells

__: membrane proteins of adjacent cells that may hook together in various kinds of junctions (gap/ tight)

__: microfilaments and other elements of cytoskeleton may be non-covalently bound to membrane proteins, a function that helps maintain cell shape and stabilizes the location of certain membrane protiens. Proteins that can bind to ECM molecules can coordinate extra and intracellular changes

Membrane carbohydrates are important in cell-cell recognition. What are two examples of this?

Cells recognize each other by ___ to certain molecules.

Are transport proteins specific? Why or why not?

_____received the Nobel Prize in 2002 for the discovery of aquaporins

__: channel proteins in the plasma membrane of a plant, animal, or microorganism cell that specifically facilitates osmosis.

__: spontaneious movement of substance down its concentration gradient, from a more concentrated to a less concentrated region

__: region along which the density of a chemical substance increases or decreases

Plant cells become ___ if it has a greater solute concentration than its surroundings.

Plant cells become __ if there is no net entry or exit of water.

phenomenon in walled cells in which cytoplasm shrivels and the plasma membrane pulls away from the cell wall (when cell loses water to hypertonic environment)

___: spontaneous passage of molecules or ions across a biological memrane with the assistance of specific transmembrane transport proteins.

Is facilitated diffusion active or passive transport? Support your response.

What type of transport proteins are involved in active transport?

What is the role of ATP in active transport?

__: coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.

__: a molecule that binds specifically to another molecule, usuall a larger one.

Review this image

Review this concept.

this measurement has a minimum value of 0 (when the solution is open to the environment); it increases as pressure increases

the diffusion of small solutes through a selectively permeable membrane

this happens when a cell swells until pressure bursts it, resulting in cell death

this measurement has a maximum value of 0; it decreases as the concentration of a solute increases

the region along which the density of a substance decreases

the function of membrane proteins that allow proteins to have binding sites with specific shapes that fit chemical messengers; external messengers may cause a shape change in protein that relays a message to the inside of the cell, usually by binding to a cytoplasmic protein

the proteins of a membrane that span the entire membrane

the proteins of a membrane that penetrate the hydrophobic core of the lipid bilayer; hydrophobic regions consist of nonpolar amino acids, while hydrophilic regions are exposed to aqueous solution on either side of membrane

n a membrane protein, specifically a transport protein, that holds onto molecules and changes their shapes in a way that shuttles them across the membrane

the function of membrane proteins that allows travel through a hydrophilic channel, or by transport proteins, which shuttle molecules across the membrane by changing shape with the help of hydrolyzing ATP

this happens when water moves, but the amount within the cell is constant; no pressure builds

the proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane, often exposed to parts of the integral proteins; attached by cytoskeleton on cytoplasmic side, and by fibers of ECM on extracellular side

any molecule that bonds specifically to a receptor site of another molecule

the ability of a solution to cause a cell to gain or lose water; depends partly on concentration of nonpenetrating solutes relative to inside of cell

the control of water balance

when a substance diffuses from an area of lower concentration to an area of higher concentration, it is moving ______ its concentration gradient

this happens when a cell shrinks and shrivels; can result in cell death if severe

this states that water will always move from an area with high water potential to an area with low water potential.