Does RuBisCO have a high affinity for CO2?

The enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes two competing reactions involving CO2 and O2 as substrates. The results indicate that at equal concentrations of the gases, Rubisco binds CO2 stronger than it does O2.

Under what conditions does the affinity of RuBisCO increase for oxygen?

Under higher concentration condition of carbon dioxide than oxygen, obviously RUBISCO shows its carboxylase activity . While, under very concentration condition of oxygen than carbon dioxide , RUBISCO may shows its oxygenase activity.

Why RuBisCO has higher affinity to carbon dioxide than oxygen?

RuBisCO has a much greater affinity for CO2 than for O2. It is the relative concentration of O2 and CO2 that determines which of the two will bind to the enzyme. This is because they have a mechanism that increases the concentration of CO2 at the enzyme site.

Which is more efficient in carbon dioxide fixation under drought condition or with high light intensity C3 or C4 plants Why?

C4 plants are more efficient than C3 due to their high rate of photosynthesis and reduced rate of photorespiration. The main enzyme of carbon fixation (Calvin cycle) is RuBisCO.

How does Rubisco bind CO2?

Rubisco takes carbon dioxide and attaches it to ribulose bisphosphate, a short sugar chain with five carbon atoms. Rubisco then clips the lengthened chain into two identical phosphoglycerate pieces, each with three carbon atoms.

What is the function of the enzyme Rubisco?

Ribulose-1,5-bisphosphate carboxylase/oxygenase, better known by the name Rubisco, is the key enzyme responsible for photosynthetic and chemoautotrophic carbon fixation and oxygen metabolism. Scientists believe it is the most abundant enzyme on the planet.

How does Rubisco fix CO2?

Rubisco takes carbon dioxide and attaches it to ribulose bisphosphate, a short sugar chain with five carbon atoms. Most of the phosphoglycerate made by rubisco is recycled to build more ribulose bisphosphate, which is needed to feed the carbon-fixing cycle.

Why does RuBP increase when CO2 decreases?

3PG levels fall, RuBP levels rise. Elimination of a source of CO2 would block the action of RUBISCO, which requires CO2 as a substrate. Intermediates in the cyclic pathway would be converted to ribulose-1,5-bisphosphate (RuBP), and the level of RuBP would rise.

Does Rubisco bind to CO2?

How do plants like sorghum and sugarcane fix carbon dioxide in nature?

C4 plants—including maize, sugarcane, and sorghum—avoid photorespiration by using another enzyme called PEP during the first step of carbon fixation. PEP fixes carbon dioxide into a four-carbon molecule, called malate, that is transported to the deeper bundle sheath cells that contain Rubisco.

What is the relation between CO2 fixation and incident light at low intensity?

In C4 plants, there is a linear relationship between PSII activity and CO2 fixation, since there are no other major sinks for electrons; thus measurements of quantum yield of PSII may be used to estimate rates of photosynthesis in C4 species.

Why Rubisco is the most abundant enzyme?

RuBisCO is thought to be the most abundant protein in the world since, it is present in every plant that undergoes photosynthesis and molecular synthesis through the Calvin cycle. It makes about 20-25\% of the soluble protein in leaves and is made on the earth at the rate of about 1000 kg/s.