Photosynthesis Flashcards
What is photosynthesis?
The process used by plants to produce glucose
What are the three stages of photosynthesis?
- Capturing light energy
- Using captured light energy to make ATP snd NADPH
- using ATP snd NADPH to make glucose from CO2
What is the function of chloroplasts?
Site of photosynthesis in plant cells
What are the 5 main structures of chloroplasts?
Inner and outer membrane, thylakoids, grana, stroma, lumen
What is chlorophyll?
- a pigment
- it absorbs part of the spectra of visible light and reflects the rest
What does chlorophyll a do?
absorbs light in blue-violet and red spectra, only pigment that transfers light energy to the reaction of photosynthesis
What are the different pigments?
Chlorophyll a, accessory pigments-chlorophyll b, carotenoids
What are the functions of accessory pigments?
B- Absorbs light in the blue-violet red spectra
Carotenoids- absorbs light in blue-violet spectra
Draw the plants cell
In notes
How does the light capturing work?
- must hit cluster of proteins and pigments in thylakoids membrane
- photons of light excites a single electron moving it to a higher energy state
- it then has 3 options
What are the 3 options the cell has when capturing light?
- Release energy as thermal energy
- transfers energy to a different electron in neighbouring pigment molecule
- electron is accepted by electron-accepting molecule
What do accessory pigments do with the energy they capture?
They transfer it yo chlorophyll a
What does chlorophyll a do with the energy?
An electron is released to ETC
Draw plant ETC
In notes
What do light reactions do?
Produce O2
What are the stages of light reactions?
1 photoexcitation
2 e transport
3 chemiosmosis
Describe photoexcitation
Absorption of light by photosystems
Photosystems are clusters containing chlorophyll a, accessory pigments, and pr- in membrane of thylakoids
What are the components of photosystems
Antenna complex
-accessory pigments, collect light energy
Reaction center
-contains chlorophyll a
-responsible for transmitting light energy into the reactions of photosynthesis
Explain what happens when energy is collected by chlorophyll before it goes to ETC
Energy from photons of light are transferred through the photosystem until it reaches chlorophyll a it then uses energy to excite an e-
e- is then passed on through the reactions of photosynthesis
