Question

1. in dna, nucleotide bonding forms a compound with a characteristic shape known as a(n)

a. beta chain
b. pleated sheet
c. alpha helix
d. double helix

1. uracil _

a. contains nitrogen
b. is a pyrimidine
c. is found in rna
d. all of the above

1. the ability of an enzymes active sites to bind only substrates of compatible shape and charge is known as _

a. selectivity
b. specificity
c. subjectivity
d. specialty

Explanation:

• For question 30: DNA has a characteristic double - helix structure formed by nucleotide bonding. Alpha - helix and beta - chain are related to protein structures, and pleated sheet is a secondary protein structure.
• For question 31: Uracil is a nitrogen - containing pyrimidine base found in RNA.
• For question 32: The ability of an enzyme's active sites to bind only substrates of compatible shape and charge is known as specificity. Selectivity is a more general term, and the other options are not the correct terms for this property.

Answer:

1. d. double helix
2. d. all of the above
3. b. specificity