Chapter 17 Flashcards
(23 cards)
What is the process of photosynthesis?
H2O gives electrons to the CO2
The CO2 becomes reduced( gains electrons) to the organic compounds
H2O becomes oxidized to O2
How are cellular respiration and photosynthesis related to?
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 )
Depending on how organisms get their nutrients , they can be classified as ?
Autotrophs= producers
Heterotrophs = consumers
What organisms perform photosynthesis ?
Bacteria (cynobacteria)
Plants
Protists (unicellular and multicellular)
Where does photosynthesis take place normally and in bacteria ?
In the chloroplast and for bacteria in the cytoplasm
What is the structure of chloroplast ?
Contains an inner and outer membrane
Thylakoid
Granum(stacks of thylakoid)
Storma(the fluid region )
Where are chloroplast usually found/
Primarily in the cells of mesophyll tissues
Where is CO2 and H2O provided by?
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
How many stages does photosynthesis occur in?
Two stages
The light dependent
Light independent (Calvin cycle)
What drives photosynthesis?
Basically the lights visible on the electromagnetic spectrum is what drives photosynthesis , so this includes 500-700 nm
How are the visible lights absorbed ?
By pigments found in the chloroplast , specifically in the thylakoid membrane
What are the different types of pigments ?
Chlorophyll a
Chlorophyll b
Carotenoids
Different pigments absorb light of different wavelengths
Why are leaves green?
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
How can we determine the wavelengths of light that can drive photosynthesis?
By using the spectrophotometer
High transmittance and low absorption
Or can be low transmitting and high absorption
What else can help plants catch more lights
The different pigments can also help with photosynthesis
What happens when the leaves turn different colours in the fall
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
What happens when a pigment absorbs light
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
Where do the light dependent reactions of photosynthesis occur
Thylakoid membrane
The pigments are found as part of the photosystems in the thylakoid membrane of the chloroplast
What does. The photosytem consists of ?
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)
How many photosystems in the thylakoid membrane ?
Photosystem ii (P680)
Photosystem i( P700)
What is a similarity in between cellular respiration and photosynthesis ?
Both involve the flow of electrons
In the light dependent reaction the flow can be linear or cyclic
What is the linear electron flow ?
It generates ATP and NADH
These will then be used by the light INDEPENDENT reactions
What generates the ATP
By photophosphorylation
Light energy is used to make ATP from ADP + Pi
