Bio Exam 2 3.5-3.9

Receptor Protein

A protein in the plasma membrane that binds to specific chemicals in the cell's external environment to regulate processes within the cell; for example, cells in the heart have receptor proteins that bind to adrenaline.

What determines whether a protein resides on the surface or extends through the bilayer?

Tertiary Structure

Cholesterol

One of the sterols, a group of lipids important in regulating growth and development; an important component of most cell membranes, helping the membrane maintain its flexibility. [Gk., chole, bile + stereos, solid + -ol, chemical suffix for an alcohol]

Recognition Protein

A protein in the plasma membrane that provides a "fingerprint" on the outside-facing surface of the cell, making it recognizable to other cells. Recognition proteins make it possible for the immune system to distinguish the body's own cells from invaders that may produce infection, and also help cells bind to other cells or molecules.

Transmembrane Protein

A protein that can penetrate the phospholipid bilayer of a cell's plasma membrane. both hydrophobic and hydrophilic regions, part of the protein can be positioned in the hydrophobic region in the center of the membrane while the other parts reside in the hydrophilic regions.

Surface Protein (peripheral proteins)

A protein that resides primarily on the inner or outer surface of the phospholipid bilayer that constitutes the plasma membrane of the cell. have an entirely hydrophilic structure and reside on the membrane surface, bound only to the head regions of the phospholipids. As a consequence, they can be positioned on either the outer or the inner side of the membrane.

Solute

A substance that is dissolved in a gas or liquid; in a solution of water and sugar, sugar is the solute.

Fluid Mosaic

A term that describes the structure of the plasma membrane, which is made up of several different types of molecules, many of which are not fixed in place but float, held in proper orientation by hydrophilic and hydrophobic forces.

Osmosis

A type of passive transport in which water molecules move across a membrane, such as the plasma membrane of a cell; the direction of osmosis is determined by the relative concentrations of all solutes on either side of the membrane.

Hypertonic

Of two solutions, that with a higher concentration of solutes. More water will move out of the cell if membran permeable.

Hypotonic

Of two solutions, that with a lower concentration of solutes. More water will move in if membran permeanle

Diffusion

Passive transport in which a particle (the solute) is dissolved in a gas or liquid (the solvent) and moves from an area of higher solute concentration to an area of lower solute concentration.

clusters of differentiation

identifying marker molecules are proteins embedded in the plasma membrane that enable a cell to bind to outside molecules and, sometimes, transport them into the cell.

Cholesterol's Role in Cell Membrane

prevents the membrane from becoming too fluid or floppy at moderate temperatures and acts as a sort of antifreeze, preventing the membrane from becoming too rigid at freezing temperatures. The membranes of some cells are about 25% cholesterol; other plasma membranes, such as those of most bacteria and plants, have no cholesterol at all.

Transport Protein

provides a channel or passageway through which large or strongly charged molecules or polar molecules can pass. Transport proteins are of a number of shapes and sizes, making possible the transport of a wide variety of molecules.

Enzymatic Protein

surface or transmembrane proteins (enzymes) that accelerate chemical reactions on the plasma membrane's surface

2 Types of Passive Transport

Diffusion, Osmosis

Simple Diffusion

Diffusion of molecules directly through the phospholipid bilayer of the plasma membrane that takes place without the assistance of other molecules; oxygen and carbon dioxide, because they are small and carry no charge that would cause them to be repelled by the middle layer of the membrane, can pass through the membrane in this way.

Facilitated Diffusion

Diffusion of molecules through the phospholipid bilayer of the plasma membrane that takes place through a transport protein (a "carrier molecule") embedded in the membrane. Molecules that require the assistance of a carrier molecule are those that are too big to cross the membrane directly or are electrically charged and would be repelled by the middle layer of the membrane.

Particles movement pattern

Down their concentration gradient I.e. food coloring in bowl

Tonicity

For a cell in solution, a measure of the concentration of solutes outside the cell relative to that inside the cell.

Isotonic

For a cell in solution, a measure of the concentration of solutes outside the cell relative to that inside the cell.no net change in the amount of water inside versus outside the cell.

...

For every 50-100 phospholipids in the membrane there is one protein molecule

Passive Transport

Molecular movement that occurs spontaneously, without the input of energy; the two types of passive transport are diffusion and osmosis.

Proteins That make up Cell Membrane

Receptor, Recognition, Transport, Enzymatic

Carbohydrate's Role

Short, branched carbohydrate chains that are attached to proteins or to phospholipid heads on the outside of the cell membrane serve as part of a membrane's fingerprint, along with recognition proteins. This fingerprint allows the cell to be recognized by other cells, such as those of the immune system.

Solvent

The gas or liquid in which a substance is dissolved; in a solution of water and sugar, water is the solvent.

beta-blockers

They bind to the beta-receptors, hold on, and block the adrenaline from doing its job. This outcome slows your heart rate, causes a reduction in blood pressure, and can bring great relief to those suffering from the sweating and trembling associated with anxiety.

two primary effects

an improper salt balance in the cells and a buildup of thick, sticky mucus—particularly in the lungs. Normal mucus helps to protect the lungs by trapping dust and bacteria. The mucus produced by someone with cystic fibrosis, however, is too thick and sticky to be moved out of the lungs, so it collects there, where it impairs lung function and increases the risk of bacterial infection. Because of the improper cellular salt balance, one way to test for cystic fibrosis is to measure the concentration of salt in the sweat—abnormally high concentrations indicate that the person may have the disease.

Cystic Fibrosis

an individual inherits from both parents incorrect genetic instructions for producing one type of transmembrane protein that allows chloride ions to get into and out of cells

Direction of osmosis

determined only by a difference in the total concentration of all the molecules dissolved in the water: it does not matter what the solutes are, only how many molecules of solutes there are. water will move toward the side with more stuff dissolved in it.