Biology Term 1

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, down a concentration gradient.

Question 2

What is concentration?

Answer 2

Concentration is a measurement of how much solute is dissolved in a given
volume of solvent.

Question 3

What is water potential and what lowers water potential?

Answer 3

The ‘potential’ (ability) for water to move freely. Solutes prevent water from moving freely.

Question 4

What is osmosis?

Answer 4

Osmosis is the diffusion of water from a more dilute solution to a more concentrated solution, across a partially permeable membrane

Question 5

Isotonic

Answer 5

When the concentration of solutes in the solution outside the cell is the same as the concentration inside the cell. The solution is isotonic to the cell

Question 6

Hypertonic

Answer 6

When the concentration of solutes is higher outside the cell than inside, the solution outside is hypertonic to the cell

Question 7

Plasmolysis

Answer 7

When the permanent vacuole of a plant cell looses water through osmosis and as a result, due to a lack of pressure the cell membrane pulls away from the cell wall

Question 8

What does turgor pressure do

Answer 8

Helps a plant keep rigid structure

Question 9

What is active transport?

Answer 9

Active transport is the process of cells transporting substances across a membrane AGAINST the concentration gradient moving molecules or ions from an area of low concentration to one of high concentration.

Question 10

Why is active transport so important?

Answer 10

Active transport allow minerals and ions in the soil that are usually in very dilute solutions (more dilute than the solution in plant root cells) to be absorbed even though its against the concentration gradient.

Question 11

What is used to test for sugar?

Answer 11

Benedict’s solution

Question 12

What is used to test for starch?

Answer 12

Iodine

Question 13

What is used to test for lipids?

Answer 13

Ethanol

Question 14

What is used to test for Protein?

Answer 14

Biuret Reagant

Question 15

What is the colour change of Iodine if starch is present?

Answer 15

Yellow-red to Blue-Black

Question 16

What forms if the test for lipids is positive

Answer 16

A cloudy white layer

Question 17

What colour will Benedict’s solution turn if there is sugar present?

Answer 17

Blue to Brick Red

Question 18

What colour will the blue Biuret Reagent turn if protein is present?

Answer 18

Purple

Question 19

Which test do you have to heat in a water bath to gain results

Answer 19

Benedict’s solution in test for sugar

Question 20

Describe how you test for starch

Answer 20

Place small amounts of food on spotting tiles
Add a few drops of iodine to each one
Iodine will turn blue-black if starch is present

Question 21

Describe how you test for Sugar

Answer 21

Place small amounts of food in test tubes.
Add enough Benedict’s solution to cover them
Agitate slightly
Place in warm water bath for 10mins
Sugar is present if solution has turned Brick Red

Question 22

Name the 3 different enzymes and what nutrient they break down

Answer 22

Carbohydrates- carbohydrase
Protein-protase
Lipids-lipase

Question 23

What are carbohydrates broken down into

Answer 23

Sugars

Question 24

What are proteins broken down into?

Answer 24

Amino acids

Question 25

What are lipids broken down into

Answer 25

Fatty acids and glycerol

Question 26

Where is carbohydrase found

Answer 26

Mouth/saliva and the small intestine

Question 27

Where is lipase found

Answer 27

Small intestine

Question 28

Where is protase found

Answer 28

Produced in stomach, small intestine, pancreas but breakdown in stomach and small intestine

Question 29

Why does temperature affect rate of reactivity

Answer 29

When you add heat energy, enzymes and molecules collide more. This increases rate of reactivity until a certain point where vibrations are too forceful that the molecule cant fit into the active site of the enzyme, they become denatured

Question 30

What are enzymes made of

Answer 30

Special proteins