What is the difference between cam c3 and c4 plants

C4 plants—including maize, sugarcane, and sorghum—avoid photorespiration by using another enzyme called PEP during the first step of carbon fixation.

This step takes place in the mesophyll cells that are located close to the stomata where carbon dioxide and oxygen enter the plant. PEP is more attracted to carbon dioxide molecules and is, therefore, much less likely to react with oxygen molecules. PEP fixes carbon dioxide into a four-carbon molecule, called malate, that is transported to the deeper bundle sheath cells that contain Rubisco. The malate is then broken down into a compound that is recycled back into PEP and carbon dioxide that Rubisco fixes into sugars—without having to deal with the oxygen molecules that are abundant in the mesophyll cells.

C3 plants do not have the anatomic structure no bundle sheath cells nor the abundance of PEP carboxylase to avoid photorespiration like C4 plants. One focus of the RIPE project is to create a more efficient pathway for photorespiration to improve the productivity of C3 crops. The RIPE project is also working to improve photosynthesis in C3 crops to ensure greater food security under future climate scenarios.

C3 plants are limited by carbon dioxide and may benefit from increasing levels of atmospheric carbon dioxide resulting from the climate crisis. But, it opens during night to gather carbon dioxide, allowing it to scatter in mesophyll cells.

Take a look at following two-part cycle that will help you in comprehending CAM pathway better. During night time. As said earlier, at night CAM plants have their stomata open which allows the entry of CO 2 that gets fixed like organic acids through phosphoenolpyruvate PEP reaction.

During day time. To store water, stomata remains shut throughout the day time, and the organic acids which hold CO 2 get released. Furthermore, an enzyme present in stroma produces carbon dioxide, which moves into Calvin cycle to enable photosynthesis. Plants that show CAM are mostly found in places where there are alternatively shortage and availability of water. Cacti, agave and clusia pratensis are few CAM plants examples. This type of carbon fixation is seen in aquatic plants as well.

Basis of Differentiation. Including cells. Mesophyll cells. Bundle sheath and mesophyll cells. Mesophyll cells in C3 and C4 both. Found in. All plants following photosynthesis. Tropical plants. Plants growing in semi-arid conditions. Plants following this type of cycle. Xerophytic, Mesophytic and Hydrophytic. Photorespiration procedure.

Seen at larger rates. Not seen much. Seen in noon time. First released product. NADPH- C3, C4, and CAM photosynthesis are three types of photosynthesis pathways with different modes of Calvin cycles. They have different mechanisms to combat photorespiration.

C3 plants do not have special features to combat photorespiration , while C4 plants minimize photorespiration by performing carbon dioxide fixation and Calvin cycle in separate cells. CAM plants, on the other hand, minimize photorespiration by performing carbon dioxide fixation and Calvin cycle at separate times. Photosynthesis is the cellular process in green plants responsible for fixing light energy from the sunlight in order to synthesize simple carbohydrates with the use of atmospheric carbon dioxide and water.

It is a process that occurs in chloroplasts. Furthermore, photosynthesis proceeds through two steps: light reaction and dark reaction. Typically, in the light reaction, chlorophylls absorb energy from the sunlight and synthesize two types of energy-rich molecules: ATP and the coenzyme, NADPH2. In contrast, in the dark reaction, these two energy-rich molecules are used for the synthesis of carbohydrates by fixing carbon dioxide. Moreover, there are three types of dark reactions occurring in plants depending on the environmental conditions.

C3 photosynthesis is the main type of photosynthesis occurring in every photosynthetic plant. Generally, it undergoes the standard mechanism of the Calvin cycle, following the light reaction.

Therefore, the first step of the Calvin cycle is the carbon dioxide fixation in the C3 photosynthesis. Here, carbon dioxide is fixed into ribulose 1,5-bisphosphate, forming an unstable six-carbon compound, which is then hydrolyzed into the three-carbon compound, 3-phosphoglycerate. Here, the first stable product of C3 photosynthesis is a three-carbon compound, hence the name.

The enzyme RuBisCO in the stromal surface of the thylakoid membrane in the chloroplast catalyzes the above reaction. Due to the catalytic imperfection of RuBisCO, it reacts highly with molecular oxygen in a process called photorespiration.

Furthermore, carbon dioxide fixation results in two molecules of 3-phosphoglycerate. During the second step, one molecule of 3-phosphoglycerate undergoes a reduction in order to form three types of hexose phosphates: fructose 6-phosphate, glucose 6-phosphate, and glucose 1-phosphate. Also, the remaining 3-phosphoglycerate is recycled, forming ribulose 1, 5-bisphosphate. C4 photosynthesis is another form of photosynthesis mainly occurring in tropic plants. Typically, the gas exchanging stomata pores remain closed most of the day time in these plants in order to reduce the excessive loss of moisture in dry and hot conditions.