Part A The image shows the reaction that occurs in the first step of fatty acid
ID: 1047012 • Letter: P
Question
Part A
The image shows the reaction that occurs in the first step of fatty acid oxidation. This reaction is catalyzed by a family of enzymes called acyl-CoA synthetases, which are classified as ligases. Select all of the following observations that support this classification.
Energy from hydrolysis of ATP is coupled to the reaction. Two reactants (substrates) are attached together to form a single product. The fatty acid donates electrons and coenzyme A accepts electrons. A phosphate is moved from ATP to coenzyme A coenzyme A CH CH CH CH CH CH CH 2 CH CH CH CH CH CH SH-CoA 2 2 ATP acyl-CoA synthetase AMP PPi ?.? CH CH CH CH CH CH CH 2 CH CH CH CH CH CH CH2 -S-CoA 2 2 2 2 2Explanation / Answer
1. ATP is converted to AMP + PPi. Therefore, the energy released from the hydrolysis of ATP must be coupled to the reaction.
2. Since it is a ligase (joins molecules), it joins two reactants to form a single product.
3. The CoASH donates electrons (from sulfur) and the fatty acid accepts it. The given statement that fatty acid donates electrons and CoA accepts it is incorrect.
4. Phosphate is not moved from ATP to CoA. Inorganic phosphate PPi and AMP are generated.