Chapter 5

Question 1

What is diffusion?

Answer 1

Movement of molecules from area of high concentration to area of lower concentration, down concentration gradient until equilibrium is achieved.

More collision in high concentration
Collision spread molecules down concentration gradient

Question 2

Why is diffusion important?

Answer 2

Gases, food molecules and waste products removed out of cell.

Question 3

What different particles diffuse?

Answer 3

Molecules
Ions
Atoms

Question 4

What is an equilibrium?

Answer 4

When the molecules are evenly distributed

Question 5

What role does the cell membrane play in diffusion?

Answer 5

Selectively permeable, meaning it lets some substances through easily and others more difficult.

Question 6

What is important when diffusion happens?

Answer 6

Obtain requirements
Get rid of waste products
Gas exchange

Question 7

How does diffusion in plants work?

Answer 7

CO2, diffuse out of leaves through stomata.
Lower concentration of CO2 in leaves as cells use up.
O2 diffuse out of leaf

Question 8

Why is diffusion important for flowers?

Answer 8

Attract pollinators

Petals fragrance diffuse from leaf to air

Question 9

Why is diffusion for respiration?

Answer 9

Capillaries around alveoli have a high concentration of CO2, low concentration of O2.
Alveoli high concentration of O2, low concentration of CO2.
O2 diffuse from high concentration in alveoli to low concentration in blood.
CO2 diffuses from high concentration in blood to low concentration in alveoli.

Question 10

Why is diffusion important for digestion?

Answer 10

Products of digestion absorbed by ileum

Solutes like glucose and amino acids can diffuse from ileum blood stream.

Question 11

What is osmosis?

Answer 11

Water molecules high water to low water potential through a selectively permeable membrane down a water potential gradient.

Question 12

What happens when plant cells is placed in a hypotonic solution?

Answer 12

Pure water, water move into cell endosmosis
Pure water has a high water potential water potential
Cell sap low water potential
Plant cell expand vacuole swells, cell becomes turgid
Cellulose wall expand slightly
Higher water potential outside plant than inside cell sap, water enter cell

Question 13

What happens to a plant cell when placed into a hypertonic solution?

Answer 13

Concentrated salt solution, water move out - exosmosis
Salt water lower - lower water potential
Cell sap high water potential
Cytoplasm, vacuole shrinks - flaccid
Membrane tears , cell undergo plasmolysis
Higher water potential in cell sap than outside, water exit

Question 14

What happens to animal cell when it is placed into a hypotonic solution?

Answer 14

no cell walls
Water move into cell by endosmosis
Swell up and burst - cannot become turgid
When in danger, certain structure will pump out water

Question 15

What happens to a animal cell when placed in a hypertonic solution?

Answer 15

Water move out of cell through exosmosis
Cell shrinks
Should always be surrounded by isotonic solution

Question 16

What is osmoregulation?

Answer 16

Regulation of the concentration of water and salts in the body

Question 17

What is the importance of osmosis?

Answer 17

Movement of water across the cell membrane to maintain water balance
1. Biological processes
2. Regulate water potential of cell
Root from soil - without water potential gradient, water lost
Not enough water, wilt - not enough pressure in cells to support plant structure
Too much water, burst, brown spots on leaves
Nutrients - need - dissolved in water
Metabolic waste products dissolves in water.

Question 18

What is active transport?

Answer 18

Movement of particles (MIA) through cell membrane from area of high concentration to area of low concentration down concentration gradient using energy from respiration.