Chapter 17

Question 1

What is the process of photosynthesis?

Answer 1

H2O gives electrons to the CO2
The CO2 becomes reduced( gains electrons) to the organic compounds
H2O becomes oxidized to O2

Question 2

How are cellular respiration and photosynthesis related to?

Answer 2

Basically the mitochondria , releases light energy and produces co2 and water( cellular respiration )
These products with the help of an input of light energy will be used by the chloroplast (photosynthesis ) to produce o2 and glucose (these products will then be used again by the mitochondria )

Question 3

Depending on how organisms get their nutrients , they can be classified as ?

Answer 3

Autotrophs= producers
Heterotrophs = consumers

Question 4

What organisms perform photosynthesis ?

Answer 4

Bacteria (cynobacteria)
Plants
Protists (unicellular and multicellular)

Question 5

Where does photosynthesis take place normally and in bacteria ?

Answer 5

In the chloroplast and for bacteria in the cytoplasm

Question 6

What is the structure of chloroplast ?

Answer 6

Contains an inner and outer membrane
Thylakoid
Granum(stacks of thylakoid)
Storma(the fluid region )

Question 7

Where are chloroplast usually found/

Answer 7

Primarily in the cells of mesophyll tissues

Question 8

Where is CO2 and H2O provided by?

Answer 8

CO2 enters through stromata (small openings)
The stroma processes the co2 and uses it during the light dependent reactions

H2O is pulled up from by the soil by xylem

Question 9

How many stages does photosynthesis occur in?

Answer 9

Two stages
The light dependent
Light independent (Calvin cycle)

Question 10

What drives photosynthesis?

Answer 10

Basically the lights visible on the electromagnetic spectrum is what drives photosynthesis , so this includes 500-700 nm

Question 11

How are the visible lights absorbed ?

Answer 11

By pigments found in the chloroplast , specifically in the thylakoid membrane

Question 12

What are the different types of pigments ?

Answer 12

Chlorophyll a
Chlorophyll b
Carotenoids
Different pigments absorb light of different wavelengths

Question 13

Why are leaves green?

Answer 13

The major pigment is chlorophyll A
Which absorbs the violet-blue and red light of the spectrum
The green is the colour it DOES not absorb hence why it’s reflected

Question 14

How can we determine the wavelengths of light that can drive photosynthesis?

Answer 14

By using the spectrophotometer
High transmittance and low absorption
Or can be low transmitting and high absorption

Question 15

What else can help plants catch more lights

Answer 15

The different pigments can also help with photosynthesis

Question 16

What happens when the leaves turn different colours in the fall

Answer 16

Chlorophyll A degrades and wear out because it’s sensitive to the cold
Other pigments such as carotenoid ( reflects yellow to red wavelengths) more prominent

Question 17

What happens when a pigment absorbs light

Answer 17

One of the electrons gets boosted to a higher energy orbital and the pigment molecule is in an excited state
When the electron comes down it releases energy

Question 18

Where do the light dependent reactions of photosynthesis occur

Answer 18

Thylakoid membrane
The pigments are found as part of the photosystems in the thylakoid membrane of the chloroplast

Question 19

What does. The photosytem consists of ?

Answer 19

Light harvesting complex ( various pigment molecules)
These complexes are surrounded by a reaction centre complex( consists of primary electron acceptor and a special pair of chlorophyll A mlcls)

Question 20

How many photosystems in the thylakoid membrane ?

Answer 20

Photosystem ii (P680)
Photosystem i( P700)

Question 21

What is a similarity in between cellular respiration and photosynthesis ?

Answer 21

Both involve the flow of electrons
In the light dependent reaction the flow can be linear or cyclic

Question 22

What is the linear electron flow ?

Answer 22

It generates ATP and NADH
These will then be used by the light INDEPENDENT reactions

Question 23

What generates the ATP

Answer 23

By photophosphorylation
Light energy is used to make ATP from ADP + Pi