BIOL 1306 Chapter 5

What factors, either directly or indirectly, are related to receptor-mediated endocytosis?

It is an active process. It increases membrane fluidity by transporting cholesterol into the cell.

Which type of transport is affected if ATP production is blocked?

Active Transport

The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called_________.

phospholipids

While water orients phospholipids into a lipid bilayer, it doesn't fix the lipids into position. This makes it

fluid

What describes the movement of substances down their concentration gradients?

Diffusion

Osmosis is the diffusion of water across a membrane in response to the concentration of one or more of the_________.

solutes

Which type of protein is embedded in the cell membrane for both active transport and facilitated transport?

carrier

Osmosis occurs as water crosses the lipid bilayer through specialized channels for water movement called_________.

aquaporins

The plasma membrane is a thin sheet of lipid molecules embedded with?

proteins.

Membrane proteins are not very soluble in water because they possess long stretches of non-polar amino acids that are?

hydrophobic.

If a cell has the same internal concentration of dissolved molecules as its outside environment, it is:

isotonic.

Transport of a solute across membrane where solute goes up its concentration gradient and uses protein carriers:

active transport.

The fluid nature of the membranes is attributed to a lateral movement of?

phospholipid molecules.

On the outer surface of the plasma membrane there are marker molecules that identify the cell type. Often they are?

carbohydrate chains

Which of the following protein classes are not found as membrane proteins?

hormones

The movement of substances from high concentration to regions where their concentration is lower is called?

diffusion

If two solutions have unequal concentrations of a solute, the solution with the lower concentration is called?

hypotonic

In bacteria, fungi, and plants, the high internal pressure generated by osmosis is counteracted by their:

cell walls 

The process often referred to as "cellular eating" is?

phagocytosis

Carrier-mediated transport of a substance down its concentration gradient is called?

facilitated diffusion.

Osmosis can only occur if water travels through the?

semipermeable membrane

A type of molecule movement that is specific and requires carrier molecules and energy is?

active transport

In a single pump cycle where sodium and potassium are exchanged and ATP is used, the following is expected:

3 sodium ions leave and 2 potassium ions enter.

The accumulation of amino acids and sugars within animal cells can occur through:

coupled transport.

Cholesterol functions in the plasma membrane to?

maintain fluidity.

A phospholipid molecule has a polar and a nonpolar end. Because of this, water molecules form?

polar bonds with the polar end of the phospholipid molecule.

You want to collect the content of human red blood cells. The type of solution researchers should use to cause lysis?

hypoosmotic.

What is the main component of an animal cell membrane?

phospholipids

Turgor pressure is observed when a plant cells environment is_________.

hypoosmotic

What initiates the sodium-potassium pump?

Three sodium ions bind to the cytoplasmic side of the protein.