Dna🥓 Flashcards
components of a nucleotide
phosphate, pentose sugar (connected with ester bond) nitrogenous base (connected with ester bond)
DNA vs RNA strandes
dna is 2, rna is 1
DNA vs RNA sugar
dna is dioxyrobose, rna is ribose
DNA vs RNA bases
dna is A T G C , rna is A U C G
DNA vs RNA subunits
dna is dna nucleotide, rna is rna nucleotide
which (rna / dna) can leave nucleus
rna
what is dna
more stable double strand that stores genetic blueprint for cells
what id rna
single stranded that transfers the genetic information for decoding
pyrimidines
1 nitrogen containing ring - cytosine, thymine, uracil
purines
2 nitrogen containing rings - guanine, adenine
polynucleotide formation
condensation reaction between 5 phosphate, and 3 hydroxyl group n the sugar of another that join two togheter - phosphodiester linkage is formed
how is double helix formed
two anti parrel chains of nucleotides linked by hydrogen bonds between complimentary base pairs
complementary base pairs
purine always with pyramide
role of rna molecules
transfer the genetic information from dna to the proteins that make up the enzymes and tissue of body
what happens to rna when finished with
degraded in cytoplasm
semi conservative dna replication
the two strands of dna double helix separates and each strand acts as a template for the creation of a new double stranded dna molecule
helicase
enzyme - which separates (unzips and unwinds) strands breaking the hydrogen bonds each strand can act as a template
primer
marks position where dna replication is starting
DNA polymerase
joins dna nucleotides togheter from 5 to 3 end only
leading strand
made continuously because nucleotides can be added one by one from 5 to 3
lagging strand
cannot be made continuously because of 3 to 5 direction, so made in fragments
DNA ligase
joins strands togheter (forms h bonds) and two double stranded molecules formed
what is mutation
replication errors that occur randomly and spontaneously
dna extraction - washing up liquid
breaks open cell and nuclear membrane
dna extraction - salt
dna negatively charged so arrtactes positive sodium ions, which neutralises dna so it can stick togheter
how atp releases energy
weak bond in last phosphate, so broken easily and it releases large amounts of energy
what is transcription
process of coping dna base sequence to produce smaller molecules of mRNA which can be transported out of nucleus
what is translation
complementary code carried by mRNA is decoded by tRNA into sequence of amino acids, occurred at ribosome
what is tRNA
amino acids become attached to tRNA, each has sequences of 3 bases called anticodon which are complimentary to codons on mRNA molecules.
sense strand
runs from 5 to 3, coding strand
antisense strand
runs from 3 to 5 does not code for proteins as complimentary so template strand
transcription process
RNA polymerase separates dna into 2 strands, one strand is used as template by rna (antisense strand). free nucleotides line up by complimentary base pairing, joined by phospodiester bonds made by rna polymerase forming single stranded mRNA.
what happens after mRNA is formed
it moves out of nuclear pore and attaches to ribosome
translation process
mRNA attaches to ribosomes, tRNA collects amino acids from cytoplasm are carries to ribosomes. tRNA attaches itself to mRNA by complemenary base pairing. the amino acids attached to tRNA join by peptide bond and tRNA detach themselves. process repeated leading to formation of polypeptide chain intill stop codon on mRNA
