t/f fatty acids with odd numbers of carbons stop the breakdown process when they get to the three carbon propionyl-CoA molecule
how do you convert an odd number of carbons fatty acid further? what vitamin is required in this step?
a carboxyl group is added and the molecule is rearranged to succinyl-CoA. Vitamin B12 is required
t/f ketone bodies are not related to the brain
F they are the body's means to provide energy to the brain when glucose levels are VERY low.
t/f starvation and diabetes can cause the need for ketone bodies
T they create low levels of ATP so ketone bodies are needed
explain how ketone bodies are made
by putting together acetyl-CoAs to make four carbon intermediates by revising the reaction catalyzed by thiolase. the four carbon molecules are converted to asia carbon molecule (called HMG-CoA) and it is broken back down to a four carbon molecule and acetyl-CoA.
t/f the smell of acetone on someones breath is an indication of a serious problem
T one of the intermediates is chemically unstable and breaks down to acetone
explain fatty acid synthesis
fatty acids are bound to a molecule called ACP (acyl carrier protein) instead of CoA.
fatty acid biosynthesis begins with the formation of a three carbon molecule called malony-CoA. this comes about by the addition of a carboxyl group (biotin is a required coenzyme). the enzyme responsible for this reaction is acetyl CoA carboxylase. it is the only regulated enzyme in fatty acid biosynthesis and is activated by citrate and inhibited by palmitate. malonyl-CoA is readily converted to malonyl-ACP
what happens in fatty acid biosynthesis after malonyl-CoA is readily converted to malonyl-ACP
two carbons of the malonyl-ACP are joined to the growing fatty acid and the carboxyl group that was added is lost as carbon dioxide.