how does light intensity affect the rate of photosynthesis?

An alternative to linear electron flow
It uses a short circuit of the linear electron flow by cycling the excited electrons back to their original starting point in Photosystem I
It only uses Photosystem I with P700 chlorophyll
NO water is split, NO O2 is formed and NO NADPH is generated
ONLY GENERATES ATP - when the concentration of NADPH gets high relative the the concentration of ATP
ATP produced by a process called cyclic photophosphorylation Cyclic Electron Flow Photorespiration 3 Phases Alternate modes of carbon fixation have evolved that minimize photorespiration and optimize the Calvin cycle.
These are the
C4 plants
CAM plants C4 Plants C4 plants live in hot, dry, sunny climates and are adapted to minimize photorespiration
Examples - sugarcane and corn.
They have specially adapted leaves with two kinds of photosynthetic cells
regular mesophyll cells
bundle sheath cells - tightly packed around the leaf vein
In mesophyll cells - CO2 is added to PEP (phosphoenolpyruvate) by the enzyme PEP carboxylase which forms a 4 carbon compound
PEP carboxylase does not bind O2 like rubisco - only CO2
4 carbon compound is exported from mesophyll cell through plasmodesmata to the bundle sheath cell where CO2 is released and available to the Calvin Cycle

CAM Plants Include succulents like cacti and pineapples
They are exposed to hot, sunny, dry weather and are adapted to minimize photorespiration.
They open their stomata at night and close them during the day
During the night CO2 is taken up and incorporated into a variety of organic acids which are stored in vacuoles until daylight
the organic acids release the CO2 during the day when light is available for the light reactions
Chloroplasts have two membranes
Stroma = fluid inside the membranes surrounding the thylakoids
Suspended within the stroma are sacs called thylakoids
Stacked thylakoids are called granum (pl - grana)

Chlorophyll - green pigment that gives the leaves their colour - resides in a thylakoid membranes.
Carotenoids are groups of accessory pigments.

Effect of changing the temperature of reactants

Plants cells contain a number of structures that are involved in the process of photosynthesis:

Photosynthesis is the synthesis of organic molecules using the ..

Photosynthesis captures energy for life on Earth. Many chemicals are made to allow life processes to occur in plants. These chemicals can move in and out of cells by the process of diffusion. Osmosis is a specific type of diffusion.

In what parts of the chloroplast does photosynthesis take place?

Overall, it is the reverse reaction of photosynthesis, but chemically, the steps involved are very different.)

Diagram of a plant cell involved in production of glucose from photosynthesis
Lack of chlorophyll/chloroplasts in the plant cells reduce the plant's capacity to photosynthesise.

Biology Notes For Olevel: Biology Notes For O-level

The two stages of photosynthesis are:
light reactions (the photo part) and
Calvin cycle (the synthesis part) The Nature of Sunlight The amount of energy is inversely related to the wavelength of light.
The shorter the wavelength, the greater the energy.

Rate of photosynthesis versus light intensity at different temperatures (2 factors)

Cement Kilns: Innovation Trends

Cyclic Electron Flow It is a cycle - the product is shunted off the cycle while the starting materials are regenerated to be used again
Occurs in the stroma, where carbon enters in the form of inorganic CO2 and leaves in the form of organic sugar
this is called carbon fixation
The cycle consumes ATP as an energy source and uses NADPH as reducing power to add high-energy electrons to CO2 to make sugar.
The product is a 3 carbon sugar called glyceraldehyde-3-phosphate (G3P)
Each turn of the Calvin Cycle fixes 1 carbon atom - the cycle must go around three times to make one G3P or 6 times to make glucose Absorption and Action Spectrums
Absorption spectrum - measures the absorption of different pigments as a function of wavelength

Provides clues to relative effectiveness of pigments driving photosynthesis


Action spectrum - a combination of all the absorbed wavelengths

Shows the overall effectiveness of different wavelengths of light in driving the process of photosynthesis.

Rate of photosynthesis versus light intensity with different CO2/NaHCO3 concentrations (2 factors)

Chemical Reactions of Oil, Fat and Fat Based Products

Therefore in graph (c) the horizontal axis could be also labelled relative light intensity, a proportional linear relationship with the rate of photosynthesis.