UNIT #1 Review Activity - Diffusion & Osmosis

Rate of diffusion is affected by

1. Temperature 2. size of the molecules 3. steepness of the concentration gradient

True or False? The molecules in a solid lump of sugar do not move.

False

Facilitated diffusion requires energy and can transport molecules against a concentration gradient.

False. Facilitated diffusion is similar to simple diffusion in that both involve movt of molecules down their concentration gradient and this movt is carried out w/o any input of energy

Which molecule listed is most likely to cause osmosis in the body?

Protein

Which of the following is the type of transport that LDL (low-density lipoprotein) uses to enter a cell?

Receptor-mediated endocytosis

True or False? Diffusion is one of the processes whereby materials are exchanged between a cell and its environment.

True

True or False? The sodium-potassium pump moves sodium out of the cell three ions at a time and returns potassium ions into the cell two ions at a time.

True

Simple diffusion is defined as the movement of

molecules from areas of higher concentration to areas of lower concentration. ex: add sugar lump to water. As it begins to dissolve, the individual molecules move from higher concentration to lower concentration in order to spread out and dissolve.

Water diffuses down its concentration gradient by __________, which is a passive transport process.

osmosis

Red blood cells put in a hypertonic solution will

shrivel and become crenated.

When sugar is mixed with water, equilibrium is reached when

the dissolved sugar molecules are evenly distributed throughout the solution.

Osmolarity

the measure of solute in a solution

The movement of water can alter the volume or pressure of a cell, which is referred to as _________.

tonicity

A cell that is immersed in a hypertonic solution loses water and shrinks, a process called ________.

crenation

Water you drink is absorbed into the blood from the digestive tract. An increase in water intake causes a(n) ___________________ in the plasma osmolarity.

decrease

Water always moves from ________ to ________ water concentration until equilibrium is reached.

higher to lower

An IV solution of 0.45% NaCl is ________________ and induces the movement of water ________________.

hypotonic; into cells

What is the name of the protein carrier involved in counter-transport?

Antiport

On average, the body is composed of about 60% water found both within the cells (______cellular fluid) and outside the cells (_______cellular fluid).

intra; extra

If the osmotic concentration of two solutions is equal, the solutions are _________ However, if the solutions have unequal osmotic concentrations, the solution with the higher concentration of solutes is ________ and the solution with the lower concentration is ________.

isotonic (aka normal saline) hypertonic; hypotonic

The directional movt of water occurs from a solution of ____________ osmolarity to a solution of ____________ osmolarity.

lesser; greater

A cell that is immersed in a hypotonic solution takes in water and swells. If the concentration difference is large enough, the movement of water into the cell can cause the cell to rupture, a process called _______.

lysis