The krebs cycle for questions 4–7, write true if the statement is true. if the statement is false, change the underlined word or words to make the statement true. 4. the pyruvic acid produced in glycolysis enters the chloroplasts if oxygen is present in a cell. 5. in the matrix, pyruvic acid is converted to lactic acid before the krebs cycle begins. 6. the compound that joins with a 4-carbon molecule in the krebs cycle is called acetyl-coa. 7. carbon dioxide is the only product of the krebs cycle that is not re- used or used in other stages of cellular respiration.

4. The given statement is false.

Correct statement: The pyruvic acid produced in glycolysis enters the mitochondria if oxygen is present in a cell.

Explanation: Pyruvate is transported into the mitochondria with the help of pyruvate translocase (transport protein located in the membrane of the mitochondria) where it is decarboxylated in order to produce acetyl-CoA.

5. The given statement is false.

Correct statement: In the matrix, pyruvic acid is converted to acetyl-CoA before the Krebs cycle begins.

Explanation: In mitochondrial matrix, pyruvate is decarboxylated to produce acetyl-CoA which enters the Krebs cycle.

Pyruvate is converted into lactic acid in the cytoplasm when cell undergoes lactic acid fermentation due to lack of oxygen such as in muscle cell.

6. The given statement is true.

Acetyl-CoA condenses with oxaloacetate (4-carbon compound) to produce citrate (6-carbon compound).

7. The given statement is True.

CO₂ is released as the byproduct of cellular respiration which is removed out of the body.

Other products such as NADH, and FADH₂ are used in electron transport chain which aids in the production of ATP.