B8 - Photosynthesis

Question 1

What is the word equation for photosynthesis?

Answer 1

Carbon dioxide + water —Light energy—> Glucose + oxygen

Question 2

What is the symbol equation for photosynthesis?

Answer 2

6CO2 + 6H2O → C6H12O6 + 6O2

Question 3

What is an endothermic reaction?

Answer 3

a reaction that takes IN heat/ energy. Cold

Question 4

What type of reaction is photosynthesis?

Answer 4

Endothermic

Question 5

What is an exothermic reaction?

Answer 5

This reaction gives OUT heat/ energy (Exit-exo). Hot

Question 6

What are some adaptions leaves have?

Answer 6

air spaces for CO2 to get in and O2 to leave by diffusion.

guard cells to open and close stomata for gas exchange.

chlorophyll in the chloroplasts to absorb light.

Broad for large surface area

thin for diffusion distance for the gases so it’s short

Question 7

What are the uses of glucose?

Answer 7

Respiration
Starch
Amino Acids
Cellulose
Fats and Oils
Use of Nitrates

Question 8

Where does respiration occur in a plant cell?

Answer 8

mitochondria

Question 9

Describe the function of starch to a plant.

Answer 9

Starch is stored in the cells of the leaves. It provides an energy store for when it’s dark or when light levels are low.

Question 10

Which solution is used to test for the presence of starch?

Answer 10

Iodine

Question 11

What are amino acids used to form in a plant cell?

Answer 11

proteins

Question 12

Which solution is used to test for the presence of proteins?

Answer 12

Biuret reagent

Question 13

In which structure of a plant cell is cellulose found?

Answer 13

cell wall

Question 14

Why are fats and oils useful to a plant?

Answer 14

used as an energy store

Question 15

What is a lipid molecule made from?

Answer 15

fatty acids and glycerol

Question 16

What are nitrates used to make?

Answer 16

amino acids

Question 17

What is the method for testing for starch?

Answer 17

1. Heat a plant leaf in boiling water for 30 seconds.
2. Add the leaf to boiling ethanol in a water bath for a few minutes.
3. Wash with water to rehydrate and soften the leaf and spread onto a white tile.
4. Add iodine solution from a dropping pipette.

Question 18

When testing for starch, why do you boil the leaf in boiling water for 30 seconds?

Answer 18

to kill the leaf, stopping any chemical reactions.

Question 19

When testing for starch, why do you add the leaf in boiling ethanol?

Answer 19

the boiling ethanol dissolves the chlorophyll and removes the green colour from the leaf - it should turn white.

Question 20

If starch is present the leaf should go…

Answer 20

blue/ black

Question 21

Would a leaf in the dark or light have more starch and colour change?

Answer 21

light

Question 22

When testing for starch, why did the leaf in the dark stay brown and the iodine didn’t change?

Answer 22

because the leaf couldn’t make anymore starch so it eats itself to create energy #cannibalism

Question 23

Enzymes are biological ____.

Answer 23

catalysts

Question 24

Enzymes speed up….

Answer 24

food digestion/ chemical reaction

Question 25

If it is too hot an enzyme can be ____.

Answer 25

denatured

Question 26

The ideal temperature for an enzyme is called the ____ _____.

Answer 26

optimum temperature