Photosyntheseis

Question 1

What organisms use photosynthesis?

Answer 1

Plants
Algae
Some types of bacteria

Question 2

What are organisms that carry out photosynthesis called?

Answer 2

Photoautotrophs

Question 3

What number balances the photosynthesis equation?

Answer 3

6 infront of everything except glucose

Question 4

What is a photon?

Answer 4

A particle of light

Each photon contains a quantum of energy

Question 5

Describe carbon fixation?

Answer 5

Process by which Carbon dioxide is converted into sugars. Eg- photosynthesis

Question 6

Why does carbon fixation require energy?

Answer 6

As it is endothermic

Question 7

What was one of the early organisms to carry out photosynthesis?

Answer 7

2 billion years ago

Cyanobacteria

Question 8

What is the relationship between oxygen and carbon dioxide?

Answer 8

The products of one are the raw materials for the others

Question 9

When do plants respire?

Answer 9

All of the time

Question 10

When do plants photosynthesise?

Answer 10

During daylight

Question 11

What is the plants compensation point?

Answer 11

When photosynthesis and respiration proceed at the same rate so the is no loss or gain of carbohydrates

Question 12

What is the name for the time taken for a plant to reach its compensation point?

Answer 12

Compensation period

Question 13

What kind of plants reach there compensation point quicker?

Answer 13

Shade plants

Question 14

How many many membranes do a chloroplast have?

Answer 14

3
Inner
Outer
Thylakoid membrane

Question 15

Describe chloroplasts?

Answer 15

Disc shaped
2-10 micrometers long
Surrounded by a double membrane- outer membrane highly permeable

Question 16

Granum?

Answer 16

Made of stacks of thylakoid membrane

Question 17

Stroma?

Answer 17

Fluid filled matrix of chloroplasts

Question 18

Thylakoid?

Answer 18

Flattened membrane bound sac

Contains photosynthetic pigments

Question 19

Where does the light dependent stage occur?

Answer 19

Thylakoid

Question 20

Where does the light independent stage occur?

Answer 20

Stroma

Question 21

What is the intergranal lamellae

Answer 21

Connects the thylakoids within a granum

Question 22

What is found in the stroma?

Answer 22

Enzymes
Starch grains
Oil droplets
Smaller ribosomes

Question 23

What do you find in the thylakoid membrane?

Answer 23

Embedded proteins to hold the photosystems in place

Photosystems

Question 24

Describe photosystems?

Answer 24

Funnel shaped

System of photosynthetic pigments

Question 25

What are photosynthetic pigments?

Answer 25

Pigments that absorb a specific wavelength of light and traps the energy associated with the light

Question 26

Examples of photosynthetic pigment?

Answer 26

Chlorophyll A and B Carotene Xanthophyll

Question 27

What happens to the light captured?

Answer 27

It is funnelled down to the primary pigment reaction centre

Question 28

What colour do both types of chlorophyll a appear?

Answer 28

Blue-green

Question 29

What colour do both types a chlorophyll a absorb?

Answer 29

Red

Question 30

What are the different absorption peaks of chlorophyll a?

Answer 30

P680- PSii | P700- PSi

Question 31

What colour does chlorophyll b appear? What wavelength does it absorb?

Answer 31

Yellow green | 400-500nm and 640nm

Question 32

What colour does carotenoids absorb? What wavelength does it absorb? What colour does it reflect?

Answer 32

Blue light 400-500nm Reflect yellow and orange light

Question 33

What colour does Xanthophylls absorb? What wavelength does it absorb? What colour does it reflect?

Answer 33

Blue and green light 375-550nm Yellow light

Question 34

What are the stages of the light dependent stage?

Answer 34

Light harvesting Photolysis Photophosphorylation Formation of reduced NADP

Question 35

What is phosphosphorylation?

Answer 35

The generation of ATP from ADP and inorganic phosphate in the presence of light

Question 36

What is the first step of non-cyclic phosphosphorylation?

Answer 36

A photon of light excites a pair of electrons in the chlorophyll molecule

Question 37

What is the second step of non-cyclic phosphosphorylation?

Answer 37

The energised electrons enter an electron carrier

Question 38

What is the third step of non-cyclic phosphosphorylation?

Answer 38

As the electrons are passed down the election carrier chain they loose energy

Question 39

What is the fourth step of non-cyclic phosphosphorylation?

Answer 39

This energy is used to pump h+ into the thylakoid space

Question 40

What is the fifth step of non-cyclic phosphosphorylation?

Answer 40

Ferredoxin accepts the elections from PSi and passes them to NADP in the stroma. This reduces the NADP

Question 41

What is the sixth step of non-cyclic phosphosphorylation?

Answer 41

As h+ accumulate a proton gradient is created across the membrane

Question 42

What is the seventh step of non-cyclic phosphosphorylation?

Answer 42

H+ diffuse through channels associated with ATP synthase enzymes. This flow of protons causes ADP and and inorganic phosphate to join producing ATP

Question 43

What enzyme catalyses the reduction of NADP?

Answer 43

NADP Reductase

Question 44

What happens to the oxygen from photolysis?

Answer 44

Some for aerobic respiration | The rest diffuses out

Question 45

What energy conversion has taken place?

Answer 45

Light to chemical

Question 46

Describe cyclic photophosphorylation?

Answer 46

``` Only uses PSi Light excites electrons Enter electron carrier system Pass back to PSi Small amount of ATP generated ```

Question 47

Which cells only contain PSi

Answer 47

Guard cells | To generate ATP to pump potassium into cells lowering the water potential for osmosis.

Question 48

What is the journey for carbon dioxide?

Answer 48

``` Through stomata Spongy mesophyll Palisade cells- cell wall Chloroplast envelope Stroma ```

Question 49

First step of Calvin cycle?

Answer 49

Carbon dioxide combines with Ribulose biphosphate | This is catalysed by rubisco

Question 50

Second step of Calvin cycle?

Answer 50

This combination is an unstable 6-carbon-compound which immediately breaks down.

Question 51

Third step of Calvin cycle?

Answer 51

The product is 2 molecules of a 3 carbon compound Glycerate-3-phosphate (GP)

Question 52

Fourth step of Calvin cycle?

Answer 52

GP is then reduced (using the hydrogens from the reduced NADP) to triose phosphate (TP)

Question 53

Last step of Calvin cycle?

Answer 53

5/6 TP molecules are reused in the cycle to regenerate Rubp

Question 54

What is RuBp

Answer 54

Ribulose biphosphate | A 5 carbon compound present in the chloroplasts

Question 55

What is TP

Answer 55

Triose phosphate | A three carbon compound

Question 56

What happens in the stroma when protons are pumped into the thylakoid space?

Answer 56

The ph in the stroma increases to 8

Question 57

What do you know about rubisco?

Answer 57

Optimum at pH 8 Is activated by the presence of ATP in the stroma Uses magnesium ions as a cofactor

Question 58

What role does ferredoxin play in PSi?

Answer 58

Activates enzymes involved in the Calvin cycle

Question 59

Why does the Calvin cycle only run in daylight?

Answer 59

Required products of LDS - ATP and reduced NADP For Rubisco to work For the concentration of magnesium ions to increase in the stroma

Question 60

Roles of TP?

Answer 60

Glucose can be converted to starch, sucrose or cellulose | Some TP synthesises amino acids, fatty acids and glycerol