Answer :
Cell code for enzymes that can convert other molecules into carbohydrates, nucleic acids and lipids. Humans can synthesize 11 out of the 20 amino acids and bacteria can synthesize all 20. Plus bacteria can synthesize many of the vitamins that humans cannot, including vitamin C. As far as humans are concerned, we can make carbohydrates and glycogen from glucose. We use some amino acids to make nucleic acids and we can synthesize lipids and cholesterol from acetyl coA. There are certain types of fatty acids we can't synthesize and we must get them from our diet.