Carbon dioxide in photosynthesis

Plants get carbon dioxide from the air through their leaves. The carbon dioxide diffuses through small holes in the underside of the leaf called stomata. (singular: stoma. plural: stomata)

The lower part of the leaf has loose-fitting cells, to allow carbon dioxide to reach the other cells in the leaf. This also allows the oxygen produced in photosynthesis to leave the leaf easily.




Carbon dioxide is present in the air we breathe, at very low concentrations. Even though it forms about .04% of the air, it is a needed factor in light-independent photosynthesis.

In higher concentrations, more carbon is incorporated into carbohydrate, therefore increasing the rate of photosynthesis in light-independent reactions.

PAR = photosynthetically active radiation.

Describe your prediction and rationale (i.e. how does photosynthesis change with light and why?)

Carbon dioxide is produced during the processes of ..

Carbon dioxide enters into the plant through the stomatal openings by the process of diffusion. Stomata are specialized cells located mainly on the underside of the leaves in the epidermal layer. The cells open and close allowing gas exchange to occur. The concentration of CO2 outside the leaf strongly influences the rate of CO2 uptake by the plant. The higher the CO2 concentration outside the leaf, the greater the uptake of CO2 by the plant. Light levels, leaf and ambient air temperatures, relative humidity, water stress and the CO2 and oxygen (O2) concentration in the air and the leaf, are many of the key factors that determine the opening and closing of the stomata.

the increased uptake of carbon dioxide into the oceans is ..

Ambient CO2 level in outside air is about 340 ppm by volume. All plants grow well at this level but as CO2 levels are raised by 1,000 ppm photosynthesis increases proportionately resulting in more sugars and carbohydrates available for plant growth. Any actively growing crop in a tightly clad greenhouse with little or no ventilation can readily reduce the CO2 level during the day to as low as 200 ppm. The decrease in photosynthesis when CO2 level drops from 340 ppm to 200 ppm is similar to the increase when the CO2 levels are raised from 340 to about 1,300 ppm (). As a rule of thumb, a drop in carbon dioxide levels below ambient has a stronger effect than supplementation above ambient.

What was the maximum rate of carbon uptake and what time of day did this occur?
Carbon dioxide levels are reduced in a greenhouse by natural air exchange and photosynthesis.

Inorganic Carbon Uptake during Photosynthesis 1

Evolutionary changes were necessary for plants to inhabit land. Aquatic plants obtain all their resources from the surrounding water, whereas terrestrial plants are nourished from the soil and the atmosphere. Roots growing into soil absorb water and nutrients, while leaves, supported by a stem superstructure in the aerial environment, intercept sunlight and CO2 for photosynthesis. This division of labour results in assimilatory organs of land plants being nutritionally inter-dependent; roots depend on a supply of photoassimilates from leaves, while shoots (leaves, stems, flowers and fruits) depend on roots to supply water and mineral nutrients. Long-distance transport is therefore a special property of land plants. In extreme cases, sap must move up to 100 m vertically and overcome gravity to rise to tree tops.

The oxidation of carbon found in organic matter and the subsequent emissions of CO2result from the following processes:

Carbon dioxide in photosynthesis

The process of photosynthesis explains why forests function as CO2sinks, removing CO2from the atmosphere. Atmospheric CO2is fixed in the plant's chlorophyll parts and the carbon is integrated to complex organic molecules which are then used by the whole plant.

Part 2- Uptake of Carbon Dioxide During Photosynthesis

To detect the uptake of CO 2 by a plant, you will use an indicator.

Because of the small size of the interfacial zone, it is very difficult to measure concentrations of ions within it. Rough estimates have been made by carefully separating the roots from the bulk of the soil, leaving only tenacious soil attached, then shaking off this remaining soil and analysing it. Such analyses do show somewhat higher concentrations (compared with those in the bulk soil) of ions such as sodium that we would expect to be largely excluded by the roots. But because the gradients in concentration are likely to be very large close to the root, these analyses are hard to assess for their consequences on the water relations of the plant. The gradients are likely to be especially large when the soil is becoming fairly dry, for the diffusion coefficient for the solutes falls by a few orders of magnitude as the soil dries, so that any excluded solutes will diffuse away from the root surface only very slowly.