Question

Mad cow disease is a fatal disease that destroys brain tissue. Researchers have found that a prion protein, which is an abnormally constructed molecule, is responsible. Which statement best describes the characteristics a protein must have to function correctly(1) A protein is a long chain of amino acids folded into a specific shape.(2) A protein is a long chain of simple sugars folded into a specific shape.(3) A protein is made of amino acids synthesized into a short, circular chain.(4) A protein is made of simple sugars synthe- sized into a short, circular chain.

Answer 1

(1) A protein is a long chain of amino acids folded into a specific shape.

Step-by-step explanation:

Amino acids serve as monomers for proteins. Several amino acids are bonded together by specific peptide bonds to form the long polypeptide chains. These polypeptide chains of each protein are folded into specific secondary and tertiary structures. This imparts specific shape to each protein. The correct amino acid sequence and specific shape are required for a protein to function properly.

For example, the right-handed alpha-helix and the left-handed superhelix of alpha keratin proteins make them strong. Any mutation in the amino acid sequence and/or change in the native shape of the proteins mostly render them nonfunctional.