Ch. 5 Biology

Channel proteins are involved in:

Passively transporting molecules through the membrane.

The type of junction found between cells in which the adjacent plasma membranes do not touch but are held together by intercellular filaments:

adhesion junction

A protein located within the cell membrane is called:

an Integral protein

Receptor proteins are involved in:

Binding signaling molecules to bring about physiological changes

___ proteins are involved in selective transport of molecules across the cell membrane.

Carrier

A transplanted organ is rejected by the host. Which protein is responsible?

Cell recognition protein

Polysaccharide that is the major complex carbohydrate in plant cell walls:

Cellulose

A structure composed of a carbohydrate chain attached to a phospholipid and is called a:

Glycolipid

What is true of both endocytosis and exocytosis?

Involve phospholipid vesicles, occur at the cell membrane, and are types of bulk molecule transport

Why does active transport require energy?

Molecules are moved against the concentration gradient AND active transport requires carrier proteins, which often require energy

When a system reaches concentration equilibrium:

Molecules continue to move but do not exhibit net passive movement in any direction

What method is used by the process of bulk transport to move macromolecules into and out of the cell?

Vesicle formation

The movement of molecules from high concentration to low concentration

diffusion

Active transport requires chemical __ to be spent to move molecules.

energy

Protein that catalyzes a specific metabolic reaction:

enzymatic protein

In bulk transport, __ refers to the movement of molecules out of the cell, whereas __ refers to their movement into the cell.

exocytosis, endocytosis

Unlike diffusion, __ requires a carrier protein

facilitated transport

The junction between cells formed by the joining of two adjacent plasma membranes which lends strength and allows ions, sugars, and small molecules to pass between cells is called a ___ junction.

gap

Hypothetically, which of the following terms would mean, "DNA with a carbohydrate chain attached?"

glycoDNA

An integral protein has a carbohydrate chain attached and is called a:

glycoprotein

The MHC cell recognition molecules are:

glycoproteins

Phospholipid membranes form bilayers because their __ heads are attracted to water, and their ___ tails face away from water.

hydrophilic, hydrophobic

A solution that is equal in solute concentration to that of the cytoplasm of a cell which causes a cell to neither lose nor gain water by osmosis is said to be a(n) ___ solution.

isotonic

At normal body temperature the consistency of the phospholipid bilayer is most similar to:

olive oil

The plasma membrane only allows some substances to cross, which means it is selectively:

permeable

The plasma membrane is a ___ bilayer.

phospholipid

Vesicles that enclose macromolecules during exocytosis are composed of:

phospholipid bilayers

The particles taken up during pinocytosis are ___ than those in phagocytosis.

smaller

A ___ is made up of two components the most common configuration being a solid solute and a liquid solvent.

solution

A fluid mixture that contains a combination of a solute (solid, liquid, or gas) and a solvent is called a:

solution

The portion of a solution that serves to dissolve a solute and is usually a liquid:

solvent

The type of junction in which adjacent plasma membrane proteins join to form an impermeable barrier is called a ___ junction.

tight

A solution's __ can be described as iso-, hyper-, or hypo-

tonicity

Osmosis is a special type of diffusion. It refers to the diffusion of __ across a membrane.

water

Osmosis is a special type of diffusion. It refers to the diffusion of ___ across a membrane.

water

What explains why a hypotonic solution causes a cell to swell?

water rushes into cell

A hypertonic solution causes a cell to shrink because:

water rushes out of the cell

A ___ is an adhesion junction that connects the cytoskeletons of adjacent animal cells creating a flexible sheet of cells.

Desmosome

Phagocytosis and pinocytosis are both examples of ___.

Endocytosis

The process of secretion in which an intracellular vesicle fuses with the plasma membrane so that the vesicle's contents are released outside the cell:

Exocytosis

The ___ is a meshwork of proteins and polysaccharides that is external to the plasma membrane, providing protection and aiding in communication.

Extracellular matrix

Diffusion and Facilitated transport are processes in which molecules move down the concentration gradient. However, ___ requires a carrier protein while ___ does not.

Facilitated transport; Diffusion

True or False: Once the concentration equilibrium is achieved across a cell membrane, molecules no longer cross the membrane.

False

True or False: The rate of diffusion is constant.

False

The components of the plasma membrane as described by the fluid-mosaic model

Phospholipids, Cholesterol, and Proteins

Carrier proteins are involved in:

Selectively transporting molecules through the membrane.

What would describe molecules that most easily diffuse through the phospholipid bilayer of a selectively permeable plasma membrane?

Small, Non-polar molecules

Cell recognition proteins are involved in:

The immune response

Tonicity refers to:

The strength of a solution compared to that of a cell

Molecules that are too large to be transported across the plasma membrane by a carrier protein are moved via:

bulk transport

The gradual change in chemical concentration between two areas of differing concentrations across a selectively permeable membrane is called a ___ ___.

concentration gradient