CHAPTER 9 Molecular Structure of DNA and RNA
Antiparallel Arrangement Arrangement in a double helix in which one strand is
running in the 5’ to 3’ direction, while the other strand
runs 3’ to 5’
B DNA Predominant form of DNA in living cells; a right-
handed DNA helix with 10 bp per turn
Base Pairs Structure in which two nucleotides in opposite strands
of DNA hydrogen bond with each other
Base Stacking In DNA, the orientation of base pairs in which the flat
sides of the bases are facing each other; provides
stability
Bulge Loop Structure in a polynucleotide duplex in which one
strand contains a nonterminal extra sequence that is not
able to base‐pair with the second strand, thereby
forming a bulge on one side of the duplex
Chargaff’s Rule The observation that in DNA the amounts of A and T
are equal, as are the amounts of C and G
Complementary DNA/cDNA DNA that is made from an RNA template by the action
of reverse transcriptase
DNA Deoxyribonucleic acid
DNase Enzyme that cuts the DNA sugar-phosphate backbone
Grooves In DNA, the indentations where the atoms of the bases
are in contact with the water in the surrounding cellular
fluid. In B DNA, there is a smaller minor groove and a
larger major groove
Internal Loop In RNA, internal loops are found where the double-
stranded RNA separates due to no base pairing between
the nucleotides
Major Groove Wide indentation in the DNA double helix in which the
bases have access to water
(DNA) Methylation Regulatory mechanism in which an enzyme covalently
attaches a methyl group (–CH₃) to a base in DNA
Antiparallel Arrangement Arrangement in a double helix in which one strand is
running in the 5’ to 3’ direction, while the other strand
runs 3’ to 5’
B DNA Predominant form of DNA in living cells; a right-
handed DNA helix with 10 bp per turn
Base Pairs Structure in which two nucleotides in opposite strands
of DNA hydrogen bond with each other
Base Stacking In DNA, the orientation of base pairs in which the flat
sides of the bases are facing each other; provides
stability
Bulge Loop Structure in a polynucleotide duplex in which one
strand contains a nonterminal extra sequence that is not
able to base‐pair with the second strand, thereby
forming a bulge on one side of the duplex
Chargaff’s Rule The observation that in DNA the amounts of A and T
are equal, as are the amounts of C and G
Complementary DNA/cDNA DNA that is made from an RNA template by the action
of reverse transcriptase
DNA Deoxyribonucleic acid
DNase Enzyme that cuts the DNA sugar-phosphate backbone
Grooves In DNA, the indentations where the atoms of the bases
are in contact with the water in the surrounding cellular
fluid. In B DNA, there is a smaller minor groove and a
larger major groove
Internal Loop In RNA, internal loops are found where the double-
stranded RNA separates due to no base pairing between
the nucleotides
Major Groove Wide indentation in the DNA double helix in which the
bases have access to water
(DNA) Methylation Regulatory mechanism in which an enzyme covalently
attaches a methyl group (–CH₃) to a base in DNA
