Osmosis,Active Transport and diffusion

Question 1

What is diffusion

Answer 1

Diffusion is the movement of particles from an area of high concentration to an area of low concentration

Question 2

Name two factors that effect diffusion

Answer 2

Temperature and concentration

Question 3

Why doe’s temperature effect diffusion

Answer 3

Because an increase in temperature increases the rate of diffusion and this is because particles gain more kinetic energy and move faster

Question 4

How does the concentration gradient effect diffusion

Answer 4

Because as the concentration gradient increases the rate of diffusion increases and creates a steeper concentration gradient

Question 5

What is a concentration gradient

Answer 5

It moves from low to high

Question 6

What is active transport

Answer 6

The movement of particles against the concentration gradient using energy.The molecules are too big to fit in the cell membrane so are carried by proteins to the cell membrane

Question 7

Where does diffusion take place in animals

Answer 7

In the alveoli and small intestine

Question 8

Explain how diffusion takes place in the alveoli(lungs)

Answer 8

Oxygen diffuses from the alveoli (where there is a high concentration of oxygen) into the blood ( where there is low concentration of oxygen).Carbon dioxide on the other hand diffuses from the blood into the alveoli

Question 9

explain How does diffusion takes place in the small intestine

Answer 9

The soluble food diffuses from the small intestine and goes into the blood

Question 10

explain In plants where and how diffusion takes place

Answer 10

It takes place in the leaves .Carbon dioxide from the atmosphere diffuses through the stomach into the leaves for photosynthesis and oxygen diffuses out the leaves into the atmosphere

Question 11

What is osmosis

Answer 11

The movement of water from a dilute solution to a concentrated solution through a semi permeable membrane

Question 12

By what method does water move in and out of cells

Answer 12

Osmosis

Question 13

What is a dilute solution

Answer 13

It contains more water

Question 14

What is a concentrated solution

Answer 14

It contains less water

Question 15

What is a semi permeable membrane

Answer 15

Only allows certain substances to pass through

Question 16

How do you work out the percentage change in mass

Answer 16

Change in mass divided by intoal mass times 100

Question 17

what does the invesitgating osmosis experiment involve

Answer 17

putting potato chips into diffrent concentration of sucrose solution to see what effect different water concentration have on them

Question 18

osmosis practical with potato chips

Answer 18

1.prepare sucrose solutions of different concentrations ranging from pure water to a very concentrated sucrose solution

2. use a cork borer to cut a potato into the same size pieces. the pieces need to be about 1cm in diameter and preferably from the same potato
3. divide the cylinders into groups of three and use a mass balance to measure the mass of each group
4. place one group in each solution
5. leave the cylcinders in solution for at least 40 mins, make sure they a;; get the same amount of time
6. remove the cylinders and pat dry gently with a paper towel, this removes excess water from the surface of the cylinders, so you get a more accurate measurement of their final masses
7. weight each group again and record your results
8. the only thing that you should change in this experiment is the sucrose solution concentration. everything else must be kept the same or your results won’t be valid