NUCLEIC ACID CHEMISTRY I

Question 1

two types of nucleic acids

Answer 1

deoxyribonucleic acid
ribonucleic acid

Question 2

monomers of a polymeric nucleic acid

Answer 2

nucleotide

Question 3

nucleotides (monomer) connected by _____________ bonds to form nucleic acid (polymer)

Answer 3

phosphodiester bonds

Question 4

sugar puckering

prevalent in RNA and a form of DNA

produces shorter phosphate-phosphate distance resulting in a more compact helical conformation

Answer 4

C3 pucker

Question 5

sugar puckering

in B-form DNA

Answer 5

C2 endo

Question 6

purines

Answer 6

adenine guanine

Question 7

pyrimidine

Answer 7

cytosine
thymine
uracil

Question 8

a base linked to a sugar without a phosphate group

___________ are named by changing the nitrogen base ending to -osine for purines and -idine for pyrimidines

Answer 8

nucleoside

Question 9

a ______– is named using the name of the nucleoside followed by the phosphate group

Answer 9

nucleotide

Question 10

the base composition of DNA generally _______ from one species to another

Answer 10

varies

Question 11

DNA specimens isolated from different tissues of the same species have the ______ base composition

Answer 11

same base

Question 12

the base composition of DNA in a given species does not _________- with an organism’s age, nutritional status or changing environment

Answer 12

change

Question 13

a sequence that is read the same way in either direction

Answer 13

palindrome

Question 14

when the inverted repeat occurs within each individual strand of DNA

Answer 14

mirror repeats

Question 15

hoogsteen pairing

Answer 15

triplex DNA

Question 16

occurs readily for DNA sequences with a very high proportion of guanosine residues

Answer 16

tetraplex

Question 17

tetraplex structure is involved in holding chromosome ends together during _________

Answer 17

mitosis

Question 18

when DNA is ___________ it winds around itself to form interwound supercoil

Answer 18

negatively supercoiled

Question 19

___________- supercoil (left hand direction), it coils around a protein core to form toroidal supercoil

Answer 19

positive

Question 20

in the case of eukaryotes

linear DNA complexed with _________- histones to form nucleosomes

Answer 20

histones

Question 21

in the case of eukaryotes

one nucleosome has ______________ histone molecules

Answer 21

8

Question 22

______ histone facilitates the coiling of the beaded fiber into higher order structures

Answer 22

H1