osmosis and diffusion

if temperature is increased,

the rate of diffusion increases

in a semi-solid, if the concentration of the solute is increased,

the rate of diffusion increases

when testing tonicity of RBCs, if the solution became transparent after adding blood cells, you could assume

the solution was hypotonic and the cells had burst

the phospholipid molecules that make up the plasma membrane have 2 major parts, the polar head which is hydrophobic and the non polar, hydrophobic tail T/F

true??

the only way to test if the RBCs are crenated is to

view them through the microscope

are cell membranes freely permeable to water

yes

does facilitated diffusion require a specific transporter for a specific molecule

yes

when testing tonicity of RBCs, if the solution became opaque after adding blood cells, you could assume

you could determine that the cells remained intact, but you could not determine whether the solution was isotonic or hypertonic without looking at the cells under the microscope

if a crystal of potassium permanganate is placed on agar and after 15 minutes the diameter of the area over which the dye has spread is 15 mm, the average diffusion rate is

60 mm/hr

selective permeability of plasma membrane

allows the passage of some molecules or ions and restricts the passage of others; protein channels and carriers facilitate the passage of polar molecules and ions

in simple diffusion, molecules move from

an area of high concentration to low concentration

RBCs in an isotonic solution

are lozenge shaped

RBCs put in a hypotonic solution will

be destroyed by hemolysis (the rupturing of RBCS and the release of their contents (cytoplasm) into the surrounding fluid (ie blood plasma)

facilitated diffusion requires

carrier proteins; does not require energy (ATP) like simple diffusion

which of the following factors would increase the rate of diffusion

decreased molecular size, larger concentration gradient, thinner media

which variables affect the rate of diffusion

density of media, size of molecules, concentration gradient, membrane permeability

RBCs are also called

erythrocytes

blood cells are protected from bursting in a hypotonic solution because of their rigid cell wall. T/F

false

Chambers A and B are placed next to each other but are separated by a film permeable to both glucose and fructose. Chamber A contains 80% glucose and 60% fructose and Chamber B contains 20% glucose and 40% fructose. Which of the following will occur?

glucose will move into chamber B faster than fructose

a _ solution has a higher concentration of water and lower concentration of solute than the cell placed in the solution

hypotonic

facilitated diffusion occurs

in either direction depending on the concentration gradient of the molecule

you made a wet mount slide of each blood/solution mixture when testing for tonicity, what did you learn from this?

in the tube with the highest concentration of solutes, the cells had shriveled (crenated)

tonicity of a solution

is related to solute content, gives information about potential changes in cell volume when cells are placed in that solution, is related to membrane permeability to solutes

tonicity

is the comparison of relative concentrations of 2 solutions, separated by a selectively permeable membrane

Human erythrocytes function best in a

isotonic solution

2 major components of plasma membrane

proteins and phospholipids

active transport

requires energy because the movement of molecules moves against a concentration gradient

RBCs put in a hypertonic solution will

shrivel and become crenated

facilitated diffusion is used to transport

sugars and amino acids

if one crystal of potassium permanganate diffuses at a rate of 240 mm/hour in a liquid and only 60 mm/hr in a semisolid, which of the following statements is true if we want the diffusion rate to be the same in both

the concentration of pot pom would need to be higher in the semisolid, the concentration of pot pom would need to be lower in the liquid

an increase in temperature will cause an increase in diffusion rate because

the frequency and force of molecular collisions increases

when looking at your data from the effect of concentration on the rate of diffusion lab, what occurred to the rate of diffusion as time elapsed

the rate of diffusion decreased for all 3 concentrations of potassium permanganate crystals