Answer:
The statement that correctly identifies the difference in the structure of proteins and polysaccharides is that only proteins are formed from amino acids joined by peptide bonds (option B)
Step-by-step explanation:
Proteins are polymers whose monomeric units are amino acids. These monomers join together to form peptides —short chains of amino acids— and proteins, joined through peptide bonds.
Amino acids that form peptides and proteins follow a specific sequence, and the interaction between them gives rise to specific shapes and configurations of each molecule.
Unlike proteins, polysaccharides are polymers formed by monosaccharides — their monomers— which can form long repetitive monosaccharides chains that are joined by glycoside bonds.
The other options are not correct because:
A. DNA is the polymer (nucleic acid) that is formed by sequences of cytosine, adenine guanine and thymine.
C. Proteins are molecules that can be folded and twisted to very specific shapes.
D. Not only proteins can be formed by long molecules.