Because the cells can only use energy in form of ATP.
Its like you can't run a diesel truck on petrol.
Answer: 3(three)
Explanation:
In the biosynthesis of phosphatidylethanolamine from ethanolamine and triglyceride, 3 high energy molecules are used in the first and second step.
The first steps occur in the cytosol, where ethanolamine is phosphorlated with ATP to give phosphoethanolamine and ADP by the enzyme ethanolamine kinases, and in the next reaction which is the rate-limiting step, phosphoethanolamine react with cytidine triphosphate (CTP) to form cytidine diphosphoethanolamine. In this reaction two molecules of phosphate group is given off.
The third step occurs in the endoplasmic reticulum CDP-ethanolamine react with diacylglycerol to form phosphatidylethanolamine.
The answer is Three high energy molecules. One molecule of ATP to form phosphorylethanolamine and two molecules of ATP to regenerate CTP from CMP.
Where are the answer choices?
Answer:
Carrier proteins move materials from one side of the cell membrane to the other. This is useful for both active transport, meaning you have to transport against the concentration gradient, and facilitated diffusion, a form of passive transport.