HYS CH6.1 - Nucleic, DNA structure

Question 1

Ribose or dexoyribose

Answer 1

H on second carbon instead of OH

Question 2

nitrogenous bases and two classes

Answer 2

have nitrogenous based in aromatic ring (residues)

purines (double)
short name but longer molecules
adenine -
guanine - NH2 group

**pyrimidines (single)
longer name but shorter
cytpsine -
uracil -H to the N
thymine - exta methul

Question 3

where is the nitrogenous based attached to the sugar

Answer 3

carbon 1

Question 4

nucleotide has how many phosphats and attached where

Answer 4

to carbon 5
nucleosides have no phosphate
nucleotides have phosphate

Question 5

nucleotides form covalent bonds to other ribose sugars where

Answer 5

phosphate oxygen to carbon five of one sugar and to oxygen of position 3 on other sugar

3-5-phosphodiester bond
each loose two phosphates when bond

Question 6

how to bases of DNA interact?

Answer 6

with hydrogen bonds
(base pairing)

complementary strands
purine always pairs with pyrimidine

Adenine (purine) and thymine (pyrimidine)–> replaced with uracil
2 bonds

guanine (purine) and cytosine (pyrimidine)
3 bonds

Question 7

what does antiparallel mean

Answer 7

enzymes read 5’ to 3’ end

Question 8

denaturation by height at 95 degrees celcius

Answer 8

seperates 2 dna strands into seperate strands

Question 9

helicases

Answer 9

breaks H bonds to seperate DNA strands

Question 10

reannealing

Answer 10

2 DNA strands that have been seperated by helicase or heat come back together to form the original double stranded DNA

Question 11

hybridization

Answer 11

when a complementary (sometimes shorter) strand of DNA is annealed to another of interest often with radioactive label

used in PCR