nucleotides and nuceic acids Flashcards
what is DNA
DNA is the genetic material, it tells the cell what to do and what proteins to make
What is RNA
RNA is mostly involved in making proteins it forms ribosomes
why is mRNA important
DNA doesnt leave the nucleus, mRNA transfers information to the ribosomes in order to make proteins
what are nucleic acids made up of
a sugar, a nitrogonous base and a phosphate group
features of the genetic code
the genetic code is the combinations of triplet codons, the code is degenerate-some amino acids are encoded for by more than one codon, the code is non-overlapping this means that each code is seperate from the other triplets in the chromosome, it is universal the same 4 bases are used in the DNA in every organism
DNA replication
-DNA helicase breaks the hydrogen bonds (unzips the genes)
-free nucleotides bond to the exposed bases and form complementary pairs
-DNA polymerase forms phosphodiester bonds between the nucleotides
-2 DNA strands are formed
ATP
made up of adenine, ribose and 3 phosphate groups
it is needed to release energy (energy is released in the hydrolysis of ATP
Transcription
RNA polymerase binds to the target gene Dna helicase is unzipping the gene into 2 strands, RNA polymerase binds free nucleotides to the template strand, the RNA nucleotides form a strand (mRNA) when RNA polymerase reaches a stop codon the strand is separated by the RNA polymerase the hydrogen bonds between the DNA strands reform, mRNA leaves the nucleus
Translation
mRNA binds to a ribosome in the cytoplasm, six bases can fit at one time, tRNA binds to the first codon, thhe anticodon allows the correct tRNA molecule to bind, each tRNA carries a specific amino acid, this repeats to create a chain of amino acids, when a ribosome reaches the stop codon the polypeptide chain is released from the ribosome
