Question

During the Calvin cycle, two 3-carbon molecules are released and join to form a 6-carbon glucose molecule. What happens to these glucose molecules in the plant?

a) Stored as starch
b) Released as oxygen
c) Used for energy in cellular respiration
d) Converted to amino acids

Answer 1

Glucose molecules formed during the Calvin cycle in plants are either used for energy in cellular respiration or stored as starch, which provides energy for later use. Excess glucose is primarily stored for the plant's future energy needs.

Step-by-step explanation:

During the Calvin cycle, glucose molecules formed from the union of two 3-carbon molecules (Glyceraldehyde-3-phosphate or GA3P) have multiple fates within the plant. These 6-carbon glucose molecules can be used for energy in cellular respiration, where energy is released and utilized to create ATP. Alternatively, the excess glucose may be stored as starch. Starch, a large carbohydrate molecule, is formed by the condensation of thousands of glucose molecules. This starch provides energy for later use by the plant and can be broken down by organisms that feed on the plant.

Moreover, plants have the ability to convert some of the glucose produced during photosynthesis into other biological molecules such as cellulose, which is used as a structural component in cell walls. Some glucose can also be converted into amino acids and other necessary compounds. However, storage as starch is one of the primary ways plants deal with excess glucose.