AP BIOLOGY

Detailed explanation-1: -Answer and Explanation: The macromolecule that requires the element sulfur (S) is c) proteins. Proteins are made of amino acids, small molecules with a carboxyl group, amino group, and a variable R-group. In some amino acids such as methionine and cysteine, sulfur forms part of the R-group.

Detailed explanation-2: -Methionine and cysteine are the two primary sulfur-containing amino acids in mammals. Methionine is an essential amino acid, obtained by dietary intake while cysteine is non-essential and a metabolite of methionine metabolism.

Detailed explanation-3: -Sulfur is the third most abundant mineral in your body. It is present in methionine and cysteine, which are two of the amino acids you use to make proteins. Both of these amino acids are present in your skin, hair, and nails where they help to make these tissues strong and flexible.

Detailed explanation-4: -Proteins contain between 3 and 6% of sulfur amino acids. A very small percentage of sulfur comes in the form of inorganic sulfates and other forms of organic sulfur present in foods such as garlic, onion, broccoli, etc.

Detailed explanation-5: -Sulfolipids are a class of lipids which possess a sulfur-containing functional group. An abundant sulfolipid is sulfoquinovosyl diacylglycerol, which is composed of a glycoside of sulfoquinovose and diacylglycerol. In plants, sulfoquinovosyl diacylglycerides (SQDG) are important members of the sulfur cycle.