A young dog has never had much energy. He is brought to a veterinarian for help and she decides to conduct several diagnostic tests. She discovers that the dog's mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanation of the dog's condition? A young dog has never had much energy. He is brought to a veterinarian for help and she decides to conduct several diagnostic tests. She discovers that the dog's mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanation of the dog's condition? His cells cannot move NADH from glycolysis into the mitochondria. His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. His cells have a defective electron transport chain, so glucose goes to lactate instead of to acetyl CoA. His cells lack the enzyme in glycolysis that forms pyruvate.

In cellular respiration, glycolysis takes place in the cytoplasm of the cell and converts glucose into 2 molecules of pyruvate. Pyruvate is then transported into the mitochondria for further oxidation.

It is transported into the mitochondria with the help of transport protein pyruvate translocase where it is decorboxylated to produce acetyl-CoA. This acetyl-CoA then enters the Krebs cycle to produce ATP (adenosine triphosphate) with the help of oxidative phosphorylation, electron transport chain and chemiosmosis.

In absence of this transport protein, the cell can not completely oxidize the glucose or carbohydrate. It switches to the metabolism of fats and amino acids in order to meet the energy demands of the cell.