quiz 18 Flashcards
How can we use the osmosis investigation to determine the concentration of plant cells?
By finding the concentration of sugar/salt solution where the plant cells do not lose or gain mass
What is the relationship between the surface area of the membrane and rate of diffusion?
As the surface area of the membrane increases, the rate of diffusion increases
When investigating the effect of sugar solution on osmosis in potato cylinders, what are some control variables
volume of sugar solution, length of potato cylinders and temperature of solutions
Which of diffusion or active transport requires energy?
active transport
Define diffusion
the movement of particles from an area of high concentration to an area of low concentration
What is the meaning of rate of diffusion?
How quickly does diffusion take place
What is osmosis?
the movement of water molecules from a dillute to concentrated solution through a partially permeable membrane
What 3 factors can affect the rate of diffusion?
temperature, surface area and concentration gradient
What is the formula to calculate percentage change in mass?
final mass - initial mass /initial mass x 100
Why do we need to dry the potato cylinders before measuring their mass?
To remove the excess water, which can affect the results
What is partially permeable membrane?
a membrane that allows some molecules thorugh
Give an example of a substance that commonly moves into cells
oxygen and glucose
When investigating the effect of sugar solution on osmosis in potato cylinders, what is the dependent variable?
change in mass of potato cylinders