osmosis and tonicity

Question 1

What do all cells need to live?

Answer 1

Obtain nutrients and get rid of waste

Question 2

What are some examples of nutrients a cell needs and why?

Answer 2

Water needed for chemical reactions and oxygen needed for cellular respiration

Question 3

Simple diffusion

Answer 3

Moving molecules from high to low concentration

Question 4

Does simple diffusion require energy?

Answer 4

No

Question 5

Is simple diffusion active or passive transport?

Answer 5

Passive

Question 6

Examples of things that do simple diffusion across the cell membrane

Answer 6

Oxygen, carbon dioxide, lipids, steroids

Question 7

Facilitated diffusion

Answer 7

Using proteins to move molecules from high to low concentrations through the cell membrane

Question 8

Example of facilitated diffusion

Answer 8

Osmosis

Question 9

Does facilitated diffusion require energy?

Answer 9

No

Question 10

Is facilitated diffusion an example of active or passive transport?

Answer 10

Passive

Question 11

Examples of substances that require facilitated diffusion?

Answer 11

Large, charged, polar molecules

Question 12

What kinds of molecules can go through the cell membrane with simple diffusion?

Answer 12

Small, nonpolar molecules

Question 13

What kinds of proteins are involved in facilitated diffusion?

Answer 13

Integral proteins

Question 14

What do integral proteins do?

Answer 14

Transport things into the cell

Question 15

What’s one example of an integral protein and its function?

Answer 15

Aquaporins transport H2O to the cell

Question 16

Active transport

Answer 16

Molecules move from low to high concentrations using ATP

Question 17

Does active transport require energy?

Answer 17

Yes

Question 18

Endocytosis

Answer 18

Bringing larger molecules into the cell using a vesicle

Question 19

Exocitosis

Answer 19

Removing large molecules using a vesicle

Question 20

Phagocytosis

Answer 20

Cell eating, example of endocytosis

Question 21

Pinocytosis

Answer 21

Cell drinking, example of endocytosis

Question 22

Tonicity

Answer 22

Ability of water to move into solutions with a high concentration of solute

Question 23

3 different environments a cell can be in

Answer 23

Isotonic, hypotonic, hypertonic

Question 24

Isotonic

Answer 24

Equal amounts of solute and water in a solution

Question 25

Movement in a isotonic solution

Answer 25

No net movement, but there is movement

Question 26

Hypotonic

Answer 26

More water and less solute in solution

Question 27

Movement in a hypotonic solution

Answer 27

Water will move into cell (think hippo, big, takes in water)

Question 28

What can happen because of a hypotonic solution to plant cells?

Answer 28

Becomes turgid

Question 29

Turgid

Answer 29

Cell membrane pushes against cell wall

Question 30

What can happen because of a hypotonic solution to animal cells?

Answer 30

Cells could lyse or burst

Question 31

Hypertonic

Answer 31

Less water, more solute in solution (hyper, crazy, wants more of the cool solute)

Question 32

Movement in a hypertonic solution

Answer 32

Out of cell

Question 33

What can happen because of a hypertonic solution to plant cells?

Answer 33

Plasmolysis

Question 34

Plasmolysis

Answer 34

Cell membrane shrinks because it’s losing water

Question 35

What happens because of a hypertonic solution to animal cells?

Answer 35

Crenation

Question 36

Crenation

Answer 36

Shriveling up of cell

Question 37

Explain how a paramecium osmoregualtes (5 steps)

Answer 37

1) Normal paramecium 2) Uses a contractile vacuole and ATP to pump in positive hydrogen ions 3) Lots of solute (H+) and less water in the paramecium creates a hypertonic solution 4) Due to the high solute concentration within the cell, water wants to get in 5) Water then fills the cell, wants to go from high to low outside the cell

Question 38

If the contractile vacuole is broken…

Answer 38

Water keeps coming in, so you can’t make a hypertonic solution and the cell will lyse/burst

Question 39

How do freshwater fish osmoregulate?

Answer 39

- Freshwater is hypotonic (more water, less solute) - A lot of water is entering their bodies through osmosis, so they need salts to counteract this - Fish gills have active transport pumps to pump in sodium ions

Question 40

Freshwater fish urine

Answer 40

Diluted because they have so much water in their bodies that they need to get rid of and their bodies retain the solute. They pee a lot because they have a lot of water storage.

Question 41

How do saltwater fish osmoregulate?

Answer 41

- Live in a hypertonic environment, more solute less water - Need to get rid of the salt from their bodies and hold on to the water needed for chemical reactions - Gills have active transport pumps to pump out the salts - They have concentrated urine because of the large amounts of solute and little water in their bodies

Question 42

Diuretic

Answer 42

Hormone that makes you urinate

Question 43

ADH antidiuretic

Answer 43

Hormone that makes you not urinate

Question 44

How does the ADH antidiuretic hormone work?

Answer 44

It tells the kidneys to make aquaporins, water transport proteins, to reabsorb the water

Question 45

If there was no ADH or if the aquaporin structure was broken/disfunctional, what would happen?

Answer 45

Humans can suffer from dehydration

Question 46

What is water potential?

Answer 46

A measure of how water moves in a solution

Question 47

How does water move in regard to water potential?

Answer 47

High water potential to low water potential

Question 48

What are the two variables that affect the osmosis and movement of water?

Answer 48

Pressure and solute concentration

Question 49

What is pressure potential?

Answer 49

Physical force

Question 50

How does water move in regard to pressure?

Answer 50

Moves in the direction of the pressure (if pressure is directed to the right, water is moving to the right)

Question 51

In an open container, pressure potential is:

Answer 51

0

Question 52

What is solute potential?

Answer 52

How much solute is in a solution

Question 53

How does solute affect water?

Answer 53

Water is attracted to solute

Question 54

What is the solute potential of pure or distilled water?

Answer 54

0

Question 55

When you add solute, what happens to the solute potential of a solution?

Answer 55

Solute potential decreases and you get negative values (less than 0)

Question 56

Water potential =

Answer 56

Pressure potential + solute potential

Question 57

What is the water potential sign called?

Answer 57

Psi

Question 58

There is less solute in the cell than in the surrounding solution. Will water move into or out of the cell? Why?

Answer 58

Water will move out of the cell because there is a high water potential in the cell and low water potential outside the cell. High -> low water potential

Question 59

Solute potential =

Answer 59

iCRT

Question 60

What does the i in the iCRT fo

Answer 60

Ionization constant

Question 61

i for NaCl

Answer 61

2

Question 62

i for sugars/sucrose

Answer 62

1

Question 63

Passive transport with regards to the concentration gradient

Answer 63

Down the concentration gradient

Question 64

Active transport with regards to the concentration gradient

Answer 64

Against the concentration gradient

Question 65

What’s an example of active transport?

Answer 65

The sodium potassium pump, where 3 Na+ ions go out and 2 K+ ions come into the cell

Question 66

Cell originally has a mass of 82 grams. After 10 minutes, it has a mass of 75 grams. What kind of solution is it?

Answer 66

Hypertonic because water is exiting the cell, and therefore mass is decreasing

Question 67

+ 15% Change

Answer 67

Hypotonic

Question 68

- 15% Change

Answer 68

Hypertonic

Question 69

Organisms try to be…

Answer 69

Isotonic

Question 70

Greatest pressure potential =

Answer 70

Hypotonic