nucleotides and nucleic acids

Question 1

what is a nucleotide made from?

Answer 1

pentose sugar
nitrogenous base
phosphate group

Question 2

what do all nucleotide elements contain?

Answer 2

C,H,O,N,P

Question 3

what does a DNA nucleotide contain?

Answer 3

phosphate group
pentose sugar of deoxyribose
base A,T,C,G

made from 2 polypeptide chains

Question 4

what type of base are adenine and guanine

Answer 4

purine
MISS PURI IS A G

Question 5

what type of base are thymine and cytosine

Answer 5

pyrimidine

Question 6

how many carbon nitrogen do purine and pyrimidine have

Answer 6

purine- 2
pyrimidine-1 (smaller)

Question 7

what does a RNA nucleotide contain?

Answer 7

phosphate group
ribose sugar
A,U,G,C

made from a single polypeptide chain

Question 8

what are 2 phosphorylated nucleotides?

Answer 8

ADP AND ATP

Question 9

what bond is between 2 nucleotides joined together

Answer 9

phosphodiester bond

Question 10

which bases pair together

Answer 10

A AND T

C AND G

Question 11

how many bonds form between A,T and C,G

Answer 11

A,T=2
C,G=3

Question 12

Describe semi-conservative replication

Answer 12

1) DNA helicase breaks hydrogen bonds between 2 polynucleotide DNA strands. Helix unzips to form 2 single strands
2)each original single strand acts as a template for a new strand, free floating DNA nucleotides join to the exposed bases on each original template strand by complementary base pairing
3) nucleotides of new strand are joined together by enzyme DNA polymerase. this forms the sugar phosphate backbone. hydrogen bonds form
4)each new DNA molecule contains one strand from the original DNA molecule and one new strand

Question 13

what are the 3 main types of RNA

Answer 13

messenger RNA-made in nucleus, 3 adjacent bases are called codon, carries genetic code from DNA in the nucleus to cytoplasm

Transfer RNA-in cytoplasm, has amino acid binding site at one end and a sequence of 3 bases called anticodon

ribosomal RNA-forms 2 subunits in a ribosome. the rRNA in the ribosome helps to catalyse the formation of peptide bonds between the amino acids
ribosomal RNA

Question 14

what is a gene?

Answer 14

a sequence of DNA nucleotides that codes for a polypeptide

Question 15

what is the genetic code?

Answer 15

the sequence of base triplets in DNA or mRNA, which codes for specific amino acids

non overlapping, degenerate and universal

Question 16

describe transcription (mRNA copy of a gene is made), Stage 1 of protein synthesis

Answer 16

RNA polymerase attaches to DNA double helix at the beginning of a gene

the hydrogen bonds between 2 DNA strands in the gene break, separating the strands and dna uncoils.

one of the strands us sued as a template for the mRNA copy.

RNA polymerase lines up free RNA nucleotides alongside strand, complementary base pairing

rna polymerase moves along seperating strands and assembling mRNA strand, hydrogen bonds reform on dna once the enzyme has passed.

when rna polymerase reaches stop codon, it stops making mRNA and detaches from DNA.

mRNA moves out of nucleus and attaches to ribosome where next stage takes place