KS3 biology Quiz on "PLANTS and PHOTOSYNTHESIS" …

Lack of chlorophyll/chloroplasts in the plant cells reduce the plant's capacity to photosynthesise.

Fall Colors, Falling Leaves, and Photosynthesis

These intermediates are characterized by their resistance to so that they can operate in higher temperatures and dryer environments than . At right, the ranges of CO2 compensation points for the three types of plants are shown. These compensation points are the values at which the plants cease to provide net photosynthesis.

coli Promotion of Photosynthesis in ChloroplastThe effects of the intensity of light on the rate of photosynthesis in plants.

Photosynthesis for Kids - Science Games and Videos

Fall is a great time of year for learning about the process that gives life to trees and most other plants. As you know, this process is called photosynthesis, which literally means “putting together with light.” As winter nears, less sunlight and less water — elements essential to the process of photosynthesis — will be available to trees. That means less food for deciduous (leaf-shedding) trees! Soon the trees’ photosynthesis “factories” will shut down, the trees will recapture nutrients from their leaves, the leaves will drop to the ground, and the tree will rest until spring when water and light return and awaken the process.

Another pigment (anthocyanin), which produces reds and purples, isn’t present all year long in most green leaves. It only shows up as the nights get cooler. In fall when trees are breaking down and reabsorbing important nutrients from their leaves, their photosynthetic tissues are especially unstable and vulnerable to too much light and other stresses. Yet trees need the energy from photosynthesis to drive the processes that allow them to recapture as many of those nutrients as possible. Just as this process begins, leaves start producing large amounts of anthocyanins near the leaf surface. Anthocyanin pigments protect the leaves’ dwindling ability to generate energy during this period.


Photosynthesis in Autumn by Nicole Schiel on Prezi

The acidity was found to arise from the opening of their stomata at night to take in CO2 and fix it into malic acid for storage in the large vacuoles of their photosynthetic cells. It could drop the pH to 4 with a malic acid concentration up to 0.3M . Then in the heat of the day, the stomata close tightly to conserve water and the malic acid is decarboxylated to release the CO2 for fixing by the Calvin cycle. PEP is used for the initial short-term carbon fixation as in the , but the entire chain of reactions occurs in the same cell rather than handing off to a separate cell as with the C4 plants. In the CAM strategy, the processes are separated temporally, the initial CO2 fixation at night, and the malic acid to Calvin cycle part taking place during the day.

Frank Turner - Photosynthesis - YouTube

Different photosynthetic organisms use differentcombinations of pigments, which have differentcolors because they absorb and reflect differentfrequencies of light.

Plants and greenalgae (plants are really advanced green algae)contain chlorophyll a (which is teal-green),chlorophyll b (which is yellow-green), andbeta-carotene (which is yellow), thus giving thema green color. Brown algae and their unicellularrelatives (e.g. diatoms) have chlorophylla,chlorophyll c, and lipid pigments calledfucoxanthins,which together give them agolden-brown color. Red algae possess chlorophylla and lipid-based pigments called phycobilins,which give them the brilliant red(or deep blue)color. These different combinations of pigmentsare more or less efficient at collecting light atcertain frequencies and at certain levels of lightintensity (too much will damage the pigment).Thus, they parcel out the Sun's energy to make themost use of it and to not compete with otherphotosynthetic organisms.

Photosynthesis: Life from Light - MIT OpenCourseWare

The connection to hot and dry conditions comes from the fact that all the plants will close their stomata in hot and dry weather to conserve moisture, and the continuing fixation of carbon from the air drops the CO2 dramatically from the atmospheric concentration of nominally 380 ppm (2004 value). If the CO2 compensation point is lower on the above scale, the plant can operate in hotter and dryer conditions. The limits are placed by the fact that begins to fix oxygen rather than CO2, undoing the work of photosynthesis. C4 plants shield their rubisco from the oxygen, so can operate all the way down to essentially zero CO2 without the onset of photorespiration.

Why do leaves change color in Fall

Fall is a great time of year for learning about the process that gives life to trees and most other plants. As you know, this process is called photosynthesis, which literally means “putting together with light.” As winter nears, less sunlight and less water — elements essential to the process of photosynthesis — will be available to trees. That means less food for deciduous (leaf-shedding) trees! Soon the trees’ photosynthesis “factories” will shut down, the trees will recapture nutrients from their leaves, the leaves will drop to the ground, and the tree will rest until spring when water and light return and awaken the process.