Lab Week 2

Question 1

Cells are…?

Answer 1

Semipermeable

Question 3

What is selectively permeable?

Answer 3

The cell decides what material will be allowed to cross the cell membrane and what cannot

Question 4

Can cells be both semipermeable and selectively permeable?

Answer 4

Yes

Question 5

What is dialysis tubing?

Answer 5

Stimulated cell membrane

Semipermeable

Question 6

What is a phospholipid bilayer?

Answer 6

Basic molecular structure of all cell membranes

Question 7

What limits what will move past the cell membrane and why?

Answer 7

1) size
- cell membranes have tiny holes, material that can go through are very tiny and big material cannot
- if big things want to go through they need special mechanisms

2) charge
- anything with a charge (ions) would find it difficult unless they have a special mechanism

Question 8

Movement of materials through cell membranes follow what law?

Answer 8

Law of diffusion

Question 9

What is diffusion?

Answer 9

Molecules and atoms that go from areas with a lot of them to areas with none or very little of them

Happens naturally

Question 10

What does diffusion described as?

Answer 10

Concentration gradient

- goes from high to low

Question 11

What is an even distribution of material?

Answer 11

Equilibrium (no more movement if this takes place)

Question 12

What is osmosis?

Answer 12

An example of diffusion when water molecules going down their concentration gradient through semipermeable membranes

Question 13

What are two conditions needed for osmosis?

Answer 13

1) water is diffusing

2) must be passing through semipermeable membrane

Question 14

What is passive transport?

Answer 14

Osmosis and diffusion do this

When no energy is needed and it goes naturally high to low (the concentration gradient goes down)

Question 15

What is active transport?

Answer 15

When cells move things across the membrane the opposite way, from low to high, needing energy because it is against the concentration gradient

Question 16

What is diffusion and osmosis interested in?

Answer 16

Diffusion- solute

Osmosis- solvent

Question 17

What is the osmotic pressure?

Answer 17

Force osmosis generates and if resisted at the same force osmosis stops

Question 18

What is hypertonic?

Answer 18

Solution has more concentration

Question 19

What is hypotonic?

Answer 19

Solution has less concentration

Question 20

What is isotonic?

Answer 20

2 solutions that are equally concentrated

Question 21

What is a cytosalt?

Answer 21

Water with stuff dissolved in it

Question 22

What happens in a hypertonic environment?

Answer 22

Water outside the cell has a greater concentration of solutes than inside the cell

Less water outside of cell than inside

So water leaves cell to go to the less concentrated area resulting in the cell shriveling up

Question 23

What happens in a hypotonic environment?

Answer 23

Water outside of cell has less concentration than inside the cell

More water outside the cell than inside the cell

So water keeps getting sucked into cell until it lyses

Question 24

What does lyse of a cell mean?

Answer 24

The cell blows up because it kept sucking in water

Question 25

Lysing if red blood cells is called?

Answer 25

Hemolysis

Question 26

What happens in an isotonic environment?

Answer 26

The cells are happy because inside and outside the cells are equal

No movement of water

Question 27

What is filtration?

Answer 27

Moving material through semipermeable membrane and spreading the material through size

Small particles pass while large ones do not

Always requires some time of force

Question 28

What is the force used in the human body for filtration?

Answer 28

Blood pressure

Question 29

What is calcium carbonate?

Answer 29

Chalk dust

Question 30

What is an osometer?

Answer 30

Demonstrates osmosis

Question 31

What is the indicator we used in the experiment that indicated starch?

Answer 31

Lugols solution

Or

Lugols iodine

Question 32

What is semipermeable?

Answer 32

Some material can cross the cell membrane others cannot