2.9

Question 1

What is the most common plant pigment

Answer 1

chlorophyll

Question 2

What is the energy in photons used for?

Answer 2

used to produce simple carbohydrates which then form more complex compounds

Question 3

what are the waste products in photosynthesis?

Answer 3

oxygen

Question 4

equation for photosynthesis

Answer 4

6CO2 + 6H20 -> C6H12O6 + 6O2

Question 5

where does photosynthesis take place?

Answer 5

in chloroplasts, this is where photons are captured

Question 6

what is the colour of leaves determined by?

Answer 6

The colour of leaves of any plant is determined by the colour of light from the visible spectrum that is reflected. Chlorophyll absorbs red and blue light most effectively and reflects green light more than other colours.

Question 7

What is the action spectrum?

Answer 7

The action spectrum shows the efficiency of photosynthesis or rate of photosynthesis achieved over the various wavelengths of light from the visible spectrum. The action spectrum is a good indicator of which wavelengths are most efficient in photosynthesis. Some wavelengths cause a higher photosynthetic rate than others. The action spectrum hows the different rates of photosynthesis that occur at different wavelengths of visible light.

Question 8

What is the absorption spectrum

Answer 8

The absorption spectrum shows which wavelength of visible light is absorbed by a particular photosynthetic pigment such as chlorophyll a or b measured by a spectrometer.

Question 9

What is the energy in photons used for?

Answer 9

to split water molecules in photolysis

Question 10

What does photolysis generate?

Answer 10

hydrogen ions, electrons & oxygen. The electrons are used to generate ATP

Question 11

what type of reaction is photosynthesis (anabolic or catabolic?)

Answer 11

anabolic, small CO2 molecules are joined together to form sugars

Question 12

What are the 2 stages in photosynthesis?

Answer 12

1. Light-dependent reaction

2. Light-independent reaction

Question 13

What are the limiting factors of photosynthesis?

Answer 13

• light
• CO2
• temp

Question 14

How is light a limiting factor of photosynthesis?

Answer 14

can only increase rate of photosynthesis to a certain point -> bc photosynthesis operates via a certain number of photosystems that capture photons -> if these are all occupied, rate cant get faster

Question 15

How is CO2 a limiting factor of photosynthesis?

Answer 15

CO2 is a raw material in the production of carbohydrates, which takes place in the light-independent -> Once all the active sites of the enzymes involved in this cyclic process are occupied with a substrate, any further increase in carbon dioxide concentration will not increase the rate

Question 16

How is temp a limiting factor of photosynthesis?

Answer 16

The optimum temperature of photosynthesis differs enormously for plants. when the temperature increases beyond the optimum level, enzymes start to denature, hence the rate of photosynthesis decreases.

Question 17

What is chromatography?

Answer 17

is a technique used to separate mixtures of substances based on the movement of the different substances on a piece of paper by capillary action.

Question 18

Where do light-dependent reactions occur?

Answer 18

in the thylakoid

Question 19

what are the products of light-dependent reactions?

Answer 19

o2, ATP & NADPH

Question 20

What is the energy conversion in light dependent reactions?

Answer 20

light energy -> chemical energy

Question 21

Where does the light dependent reaction occur?

Answer 21

in the storma

Question 22

What does the light independent reaction start with?

Answer 22

CO2, ATP & NADPH

Question 23

what are the products of the light independent reaction?

Answer 23

glucose, ADP & NADP

Question 24

What is the energy conversion in light independent reactions?

Answer 24

chemical energy from the molecules -> chem energy in the bonds of glucose

Question 25

Which molecules is oxygen released into air as a product of photosynthesis?

Answer 25

water only

Question 26

What is the function of the acetone used in paper chromatography to separate photosynthetic pigments?

Answer 26

It dissolves pigments, allowing them to travel up the paper strip. Photosynthetic pigments are non-polar substances that can’t be dissolved in water. Acetone is a non-polar solvent that can dissolve non-polar substances so that they can run up the paper strip.

Question 27

Why do most plants appear to be green?

Answer 27

because red & blue wavelengths are absorbed and green is reflected

Question 28

What is the source of the oxygen released into the atmosphere in photosynthesis?

Answer 28

water

Question 29

Which type of light is least useful for photosynthesis in terrestrial plants?

Answer 29

green light

Question 30

Photolysis equation

Answer 30

H20 -> 4e- + 4H+ + O2

Question 31

Where does all the oxygen come from in photosynthesis?

Answer 31

oxygen

Question 32

Is photosynthesis endothermic or exothermic?

Answer 32

endothermic

Question 33

What happens in light dependent reactions?

Answer 33

-ATP & H(carried by NADPH)
-ATP & H combine to form complex organic compounds
-

Question 34

What was the first organism to perform photosynthesis?

Answer 34

cyanobacteria

Question 35

Difference between light-dependent & light-independent reactions

Answer 35

Light-dependent reactions use light energy to produce ATP & to split water. Light-independent use ATP & H ions to fix CO2

Question 36

Do all plants have the same action/absorption spectrum?

Answer 36

No

Question 37

What does light intensity refer to?

Answer 37

the amount of light of a given wavelength, which is available to the plant