DNA structure and function

Question 1

What does DNA consist of?

Answer 1

2 long polynucleotide chains

Question 2

what is the predominant form of DNA?

Answer 2

right-handed B form

Question 3

hydrogen bonds exist where within the strand?

Answer 3

between the bases

Question 4

where do covalent bonds exist within the strand? more specifically, what are they called?

Answer 4

exist between the nucleotides along sugar-phosphate backbone; phosphodiester bonds

Question 5

which bonds are considered weak?

Answer 5

hydrogen bonds

Question 6

when do hydrogen bonds form?

Answer 6

when a hydrogen is bw 2 electron attractors

Question 7

what contributes to overall stability of the double helix?

Answer 7

hydrogen bonds

Question 8

how many hydrogen bonds bw a C and G?

Answer 8

3

Question 9

how many hydrogen bonds bw an A and T?

Answer 9

2

Question 10

what do nucleotides consist of?

Answer 10

nitrogenous base, 5 carbon sugar, and phosphate group

Question 11

subunits of nucleic acids

Answer 11

nucleotides

Question 12

“rungs” on DNA ladder

Answer 12

bases

Question 13

strong chemical bond? how is it formed?

Answer 13

covalent bonds; sharing of electron pairs with a balance of attractive and repulsive forces

Question 14

which bases are purines? how many rings?

Answer 14

adenine and guanine; 2

Question 15

which bases are pyrimidines? how many rings?

Answer 15

cytosine and thymine; 1

Question 16

what about the bases constitutes the genetic code?

Answer 16

variability of the bases on a DNA strand

Question 17

where is the nitrogenous base attached to deoxyribose?

Answer 17

1’ carbon

Question 18

where is the hydroxyl group located on deoxyribose?

Answer 18

3’ carbon

Question 19

where does the phosphate group attach to deoxyribose?

Answer 19

5’ carbon

Question 20

how/where are nucleotides joined? making what? what is the bond called?

Answer 20

joined by the phosphate group of one nucleotide attaching to 3’ carbon of next nucleotide; polynucleotide; phosphodiester bond

Question 21

what does antiparallel mean? why does it occur? what principle is it called?

Answer 21

one strand compliments the other, necessary bc of base pairing requirements; “complementarity”

Question 22

how is a nucleotide sequence read on a DNA strand?

Answer 22

5’ to 3’

Question 23

why can’t a purine bond with a pyrimidine?

Answer 23

because of the chemical structure of the cyclic compound

Question 24

_____ groups of one base bind with ________ groups of the other

Answer 24

keto; amino

Question 25

what happens if wrong bases pair up?

Answer 25

DNA repair must be done

Question 26

nitrogen-containing rings, either purines or pyrimidines

Answer 26

bases

Question 27

what for the principle “complementarity”?

Answer 27

two strands of DNA are antiparallel; meaning one strand compliments the other

Question 28

what does base pairing do?

Answer 28

holds monomers in place and thereby controls the selection of which base will be added to the strand.

Question 29

how is the double helix formed?

Answer 29

each DNA strand is coiled around the same helical axis and intertwined

Question 30

all proteins no matter how complex or simple are __________ by DNA.

Answer 30

templated(molded)

Question 31

what is an exon?

Answer 31

portion of the code for the protein that is spliced together to form functional gene

Question 32

what is an intron?

Answer 32

portion of the code from the protein that is unused.