In allosteric interactions a. changes that take place in one site of a protein cause changes at a different site or subunit. b. disulfide bonds are broken. c. metal ions always bind to the protein. d. proteins that consist of a single polypeptide chain form aggregates.

Which of these statements is true about autotrophs, but not heterotrophs? a. they use sugar and oxygen to make carbon dioxide and water.b. they use chlorophyll and oxygen to make carbon dioxide and water.c. they use sunlight, water, and carbon dioxide to make sugars.d. they use sunlight, water, and oxygen to make chlorophyll.