Chapter 3 - Movement Into and Out of Cells

Question 1

what are particles?

Answer 1

the smallest pieces of which a substance is made; can be molecules, atoms and ions

Question 2

what is kinetic energy?

Answer 2

energy of moving objects

Question 3

what is diffusion?

Answer 3

the net movement of particles from a region of higher concentration to a reign of lower concentration (down a concentration gradient) as a result of their random movement

Question 4

what is net movement?

Answer 4

overall or average movement

Question 5

what is a concentration gradient?

Answer 5

an imaginary ‘slope’ from high concentration to low concentration

Question 6

what is a compound?

Answer 6

a substance formed by the chemical combination of two or more elements in a fixed proportion

Question 7

what does it mean by a partially permeable membrane?

Answer 7

a membrane (very thin layer) that lets some particles move through it but prevents others from passing through

Question 8

what is osmosis?

Answer 8

the diffusion of water molecules through a partially permeable membrane

Question 9

what is osmosis in terms of water potential?

Answer 9

the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane

Question 10

what does it mean if a solution has a high water potential?

Answer 10

there are a lot of water molecules - dilute solution

Question 11

what does it mean if a solution has a low water potential?

Answer 11

there aren’t many water molecules - concentrated solution

Question 12

what does water potential gradient mean?

Answer 12

a difference in water potential between two areas

Question 13

what does it mean if a plant cell is turgid?

Answer 13

its tight and firm

Question 14

what is turgor pressure?

Answer 14

the pressure of the water pushing outwards on a plant cell wall

Question 15

what does it mean if a plant cell is described to be flaccid?

Answer 15

its soft

Question 16

what does it mean if a cell is described to be plasmolysed?

Answer 16

the cell membrane tears away from the cell wall

Question 17

what is active transport?

Answer 17

the movement of molecules or ions through a cell membrane from a region of lower concentration to a region of higher concentration (against the concentration) using energy from respiration

Question 18

what are carrier proteins (protein carriers)?

Answer 18

protein molecules in cell membranes that can use energy to change shape and move ions or molecules into or out of a cell