Topic 1 – Key Concepts in Biology-Cell Transport

Question 1

what is simple diffusion?

Answer 1

net movement of molecules from an area of high concentration to low concentration down a concentration gradient

Question 2

what molecules enter and leave cells via simple diffusion through cell membrane?

Answer 2

small molecules e.g. oxygen, water, glucose, and amino acids.

Question 3

what factors affect rate of diffusion?

Answer 3

temperature, concentration gradient, surface area of cell membrane

Question 4

define osmosis

Answer 4

net movement of water molecules from an area of high water concentration to area of low water concentration through a partially permeable membrane

Question 5

what is active transport?

Answer 5

movement of molecules across cell membrane from low concentration to area of high concentration against concentration gradient

Question 6

how is percentage change in mass?

Answer 6

final mass-initial mass/initial mass x 100