PHOTOSYNTHESIS: The Chemical Basis of Life Flashcards
Light has the characteristics of both a
wave and a particle.
characterized by wavelength (λ) and frequency (v)
Wave
distance between 2 wave crests
Wavelength (λ)
number of wave crests that pass through a given distance at
the speed of light (c)
Frequency (v)
light particle each of which contain an amount of energy called quantum
Photon
where h is Planck’s constant (6.626 × 10–34 J s)
Planck’s Law
Site of Photosynthesis
Chloroplast
Most of the thylakoids appear to be very closely associated with each other forming the stacked membranes of
grana lamellae
the exposed membranes in which stacking is absent are known as
stroma lamellae
absorbs light primarily in the blue and red regions of the visible
spectrum.
Chlorophyll
yellow to orange photosynthetic pigments absorb wavelengths of light
different from those absorbed by chlorophyll, thereby expanding the spectrum of light
that provides energy for photosynthesis.
Carotenoids
The principal raw materials for photosynthesis are water and carbon dioxide
Photosynthesis
begin as chlorophyll absorbs light energy, which causes
one of its electrons to move to a higher energy state
Light Dependent Reaction
CO2 and water from the environment are enzymatically combined
with a five-carbon acceptor molecule to generate two molecules of a three-carbon intermediate.
CALVIN CYCLE
First, a key enzyme, rubisco, combines a molecule of CO2 with RuBP
CO2 uptake
The PGA molecules are then converted to glyceraldehyde-3- phosphate (G3P) using NADPH and ATP.
Carbon reduction
Note that although 2 of the 12 G3P molecules formed during six turns of the cycle were removed from the cycle, 10 G3Ps remain, containing 30 carbon atoms in all.
RuBP regeneration
Factors that Regulates the Process (6)
- Light intensity and Temperature
- Water
- Carbon Dioxide
- Mineral
- Energy Efficiency
- Enzymes of Light dependent reaction regulates Calvin Cycle
There are times when the CO2 in the stroma depletes in number
Photorespiration
