Lab 3

Question 1

Diffusion is…

Answer 1

the movement of molecules from where there are a lot of a given molecule (high concentration) to where there are fewer of the given molecule (low concentration)

Question 2

What is meant by selectively permeable membrane?

Answer 2

The cell membrane will let some things in/out and not others.

Question 3

Benedict’s reagent test for…

Answer 3

The presence of glucose

Question 4

What color was Benedict’s reagent?

Answer 4

Blue

Question 5

What does Lugol’s iodine test for?

Answer 5

The presence of starch

Question 6

What color was Lugol’s iodine?

Answer 6

Brownish

Question 7

What is hypertonic?

Answer 7

A solution of high pressure/concentration

Question 8

What is hypotonic?

Answer 8

A solution of low pressure/concentration

Question 9

What is isotonic?

Answer 9

A solution of equal pressure/concentration to that around it.

Question 10

A solution consists of…

Answer 10

A solute + a solvent

Question 11

Which is a polysaccharide, starch or glucose?

Answer 11

Starch

Question 12

Which is a monosaccharide, starch or glucose?

Answer 12

Glucose

Question 13

Osmosis is…

Answer 13

the diffusion of water across a selectively permeable membrane from where this a lot of water (low solute concentration) to where there is less water (high solute concentration).

Question 14

Why is the saline solution in IV bags have a 0.9% NaCl concentration and what is it good for?

Answer 14

Because the solution is isotonic. It is good for hydration, sodium replensishment and as a diluent for compatible drugs

Question 15

Filtration is an important mechanism for maintaining _____ in an organism.

Answer 15

Homeostasis

Question 16

When running testing for glucose in the Diffusion project, why did the beaker solution turn blue?

Answer 16

Because the glucose was a higher concentration within the tubing and the molecules were small enough to penetrate the semi-permeable membrane.

Question 17

Why did the starch not appear in the beaker solution?

Answer 17

Because the higher concentration of molecules of starch within the tubing was too large to pass through the membrane.

Question 18

The solution that has passed through a filter is called

Answer 18

Filtrate

Question 19

NaCl + Ag(NO₃) ⟶ Na(NO₃) + AgCl

What is the solute (solid)?

What is its name?

Answer 19

• AgCl
• Silver Chloride

Question 20

Parameca live in

Answer 20

fresh water

Question 21

The paramecia take in water through the process of

Answer 21

Osmosis

Question 22

Paramecia expel water through the process of

Answer 22

active transport

Question 23

_____ is the key process by which useful subastances like oxygen and nutrients move into cells and waste products leave.

Answer 23

Diffusion

Question 24

What is ABCA1?

Answer 24

A membrane protein that regulates cellular choleserol and phospholipid homeostatis

Question 25

What is another name for ABCA1?

Answer 25

Cholesterol Efflux Regulatory Protein (CERP)

Question 26

What is the cellular function of ABCA1?

Answer 26

The removal of cholestrol from the cell

Question 27

What happens if the ABCA1 protein stops working?

Answer 27

Cholestrol is not able to be removed from cytopasm which would promote blood vessel thinckening and hardening.

Question 28

Why does O₂ diffuse from the alveolus to the capillary?

Answer 28

The concentration of O₂ is hypertonic in the alveolus and hypotonic in the capillary.

Question 29

What is a food preserved by salt?

Answer 29

Meat

Question 30

What is a food preserved by sugar?

Answer 30

Fruit

Question 31

On a filter, what determines what molecules will pass through or not?

Answer 31

Meolecular size.

Question 32

A membrane contains of 20% sucrose & 80% H₂O.

The solution outside of it contains 100% H₂O and 0% sucrose.

1. In what direction will the sucrose diffuse?
2. In what direction will the water diffuse?

Answer 32

1. Inside to out
2. Outside to in

Question 33

A membrane consists of 20% sucrose and 80% H₂O.

The solution outside it consists of 20% sucrose and 80% H₂O.

1. In which direction will the sucrose flow?
2. In which direction will the H₂O flow?
3. Why?

Answer 33

1. There is no concentration difference so there is no diffusion
2. as above
3. Because of the isotonic relationship

Question 34

A membrane has 20% sucrose and 80% H₂O.

The solution outside it has 40% sucrose and 60% H₂O.

1. Which direction does the sucrose flow?
2. Which direction does the H₂O flow?

Answer 34

1. Outside to in
2. Inside to out