cell biology - diffusion

Question 1

what is diffusion?

Answer 1

the spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration

Question 2

what are cells surrounded by? how is this transported?

Answer 2

a high concentration of oxygen
oxygen transported in bloodstream from the lungs

Question 3

how do oxygen molecules move into the cell?

Answer 3

by diffusion from an area of higher concentration to an area of lower concentration

Question 4

do carbon dioxide molecules enter or leave the cell?

Answer 4

leave by diffusion

Question 5

what is urea and where is it produced? where does it diffuse?

Answer 5

waste product produced in cells. diffuses out of cell into blood paste where it is excreted by the kidney

Question 6

what is the rate of diffusion affected by?

Answer 6

concentration gradient, temperature and surface area of cell membrane

Question 7

how does the concentration gradient affect diffusion?

Answer 7

the greater the concentration gradient, the faster diffusion takes place
smaller = slower

Question 8

how does temperature affect rate of diffusion?

Answer 8

high the temperature, the greater rate of diffusion because particles have more kinetic energy and will move faster

Question 9

how do the surface area of the cell membrane affect rate of diffusion?

Answer 9

the larger the surface area of cell membrane, the greater the rate of diffusion