movement in and out of cells

Question 1

what is diffusion

Answer 1

This is the movement of molecules from a region of high concentration to a region of low concentration down the concentration gradient.
the energy for diffusion comes from
the kinetic energy of random movement of
molecules and ions
This results in random movement of molecules until equilibrium is reached

Question 2

Describe the importance of diffusion of gases and

solutes

Answer 2

The diffusion of gases and solutes is important as without it, molecules which are needed for life, for example glucose and oxygen for respiration, would not be able to get to the places they are needed. Water is needed as a solvent

Question 3

Factors influencing faster diffusion:

Answer 3

Larger concentration gradient

Higher temperature

Smaller surface area

Question 4

what is osmosis

Answer 4

Movement of water molecules from a region of high-water potential to a region of low water potential, through a partially permeable membrane

Question 5

what is plasmolysis

Answer 5

Conc. of solute outside cell > conc. inside cell → cell shrinks (Plasmolysis)

Question 6

what is turgidity

Answer 6

Conc. of solute outside cell < conc. inside cell → cell swells (Turgid)

Question 7

osmosis in plants

Answer 7

Increasing solute concentration inside of cell causes cell to become turgid, vacuole fills up.

Decreasing solute concentration inside of cell causes cell to become flaccid, losing water and vacuole gets smaller. Cell body shrinks, pulling away from cell wall

Question 8

osmosis in animals

Answer 8

Increasing solute concentration inside of cell can cause cell to explode as a result of it having too much water, crenation.

Question 9

what is active transport

Answer 9

Movement of particles through a cell membrane, from a region of lower concentration to a region of higher concentration against a concentration gradient, using energy released during respiration

Question 10

why is active transport needed

Answer 10

Active transport is needed when an organism wants to optimize the amount of nutrients it can take up - ion uptake by root hairs and uptake of glucose by epithelial cells of villi.