2.1 Nucleic Acids

Question 1

monomer for DNA

Answer 1

nucleic acids

Question 2

purines

Answer 2

2 rings
Adenine
Guanine

Question 3

pyrimidines

Answer 3

1 ring
Thymine
Cytosine

Question 4

nucleoside

Answer 4

sugar + base
no phosphates to make the phosphodiester bonds

Question 5

nucleotide

Answer 5

sugar + base + phosphate

Question 6

polarity of nucleotide sequences

Answer 6

read from 5’ to 3’

Question 7

bonds in nucleotide sequences

Answer 7

phosphodiester bonds

Question 8

where is new incoming nucleotide added in DNA

Answer 8

3’ of the molecule

Question 9

primary structure in DNA

Answer 9

sequence
1 strand of DNA

Question 10

secondary structure in DNA

Answer 10

helix
2 strands coming together

Question 11

tertiary structure in DNA

Answer 11

helix winds up to form chromatin, DNA that wound up

Question 12

importance of major and minor grooves

Answer 12

regions where the proteins bind to the DNA
different proteins recognize the different sequences of bases, bind to specific regions of the DNA

Question 13

what type of interactions happen between base pairs

Answer 13

hydrogen bonds

Question 14

which bases are held together by 2 H bonds

Answer 14

A and T

Question 15

which bases are held together by 3 H bonds

Answer 15

G and C
stronger, more stable because more bonds

Question 16

base stacking

Answer 16

ID-ID interactions between the non polar, flat surfaces of the bases that contribute to them packing together

hydrophobic effect at play here too! –> tightly pack DNA = minimal interaction with water

Question 17

why purine-pyrimidine pair

Answer 17

allows for a uniform structure
- same distance between bases in the two strands
- same, regular hydrogen bonding pattern
- same stacking interactions between bases above and below

it’s just more stable

Question 18

difference between ribose and deoxyribose

Answer 18

ribose has a hydroxyl group where deoxyribose has a hydrogen

Question 19

U vs T

Answer 19

uracil has a hydrogen where thymine has a methyl group

Question 20

DNA vs RNA

Answer 20

DNA:
- deoxyribose sugar
- A, T, C, G
- monophosphate at 5’ end
- very large size
- double strand

RNA
- ribose sugar
- A, U, C, G
- triphosphate at 5’ end
- smaller size
- single strand

Question 21

gene expression

Answer 21

turning on of a gene

Question 22

gene regulation

Answer 22

processes that control whether gene expression occurs at a given time, in a given cell, or what level

Question 23

Nucleoside phosphate

Answer 23

nucleotide with 1+ phosphate groups

Question 24

Chargaff’s base pairing rule (Watson-Crick)

Answer 24

number of molecules of the nucleotide base adenine (A) always equals the number of molecules of thymine (T) and the number of molecules of guanine (G) always equals the number of molecules of cytosine ©

Question 25

Base stacking contributes to stability of the double helix how

Answer 25

○ Interactions between bases in the same strand
○ Non-polar, flat surfaces of the bases tend to group together away from water molecules
Stacks on top of one another as tightly as possible