FILL IN THE BLANK 14 : Both starch and glycogen are forms of ——— 15: Describe the structure of a lipid . It has a ——— head and a ———— tail 16: list and describe the levels of protein structure . A . B. C. D. 17: Animals store glucose as ——— plants as ——— 18: enzymes lower the ——————— for a reaction . 19: what is the function of the “R group “ in a protein ?

Answer: 14: Both starch and glycogen are forms of polysaccharides. 15: Describe the structure of a lipid. It has a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail. 16: List and describe the levels of protein structure.

A.) Primary structure - the sequence of amino acids in the polypeptide chain.

B.) Secondary structure - the localized folding of the polypeptide chain into structures such as α-helices and β-pleated sheets.

C.) Tertiary structure - the three-dimensional shape of the entire polypeptide, including all its bends and folds.

D.) Quaternary structure - the arrangement of multiple polypeptide chains into a functional protein complex. 17: Animals store glucose as glycogen; plants as starch. 18: Enzymes lower the activation energy for a reaction. 19: The function of the “R group” in a protein is to determine the chemical nature (e.g., acidic, basic, hydrophobic, hydrophilic) of the amino acid, which affects the protein's structure and function.