protein production

what is DNAs role in protein synthesis?

contains all the information needed to make proteins

what is RNAs role in protein synthesis?

acts as intermediary and can be used over and over to make the same type of protein

what are the parts of RNA?

-Sugar = ribose

-Phosphate group

-Nitrogenous base (4)

-Adenine = A

-Guanine = G

-Cytosine = C

-Uracil = U

-Purines & pyrimidines

what are complimentary strands?

follow same base pair rule, except U replaces T

what are the types of RNA?

-mRNA

-rRNA

-tRNA

what is mRNA?

messanger

what is rRNA?

ribosomal

what is tRNA?

transfer

what are the stages of protein synthesis?

-transcription

-translation

what is transcription?

-assemble RNA from DNA template

what is translation?

-RNA and ribosomes assemble amino acids into a long chain protein.

-Takes place in the cytoplasm in three parts

what happens during transcription?

-Takes place in the nucleus

-DNA unzips and one strand acts as template for making RNA

-RNA polymerase assembles nucleotide bases to region of DNA template

-Starts at a promoter site that signals RNA growth, DNA sections are called triplets

-RNA grows, then detaches from DNA and DNA re-zips

-RNA is modified by snipping out unnecessary sections & RNA leaves the nucleus

what are the parts of translation?

1. initiation

2. elongation

3. termination

what happens in initiation?

-strand of mRNA attaches to two ribosomal subunits to make complex

-rRNA will be helping by ‘taping’ ribosome complex together

-Start codon (AUG) is the start point

-P and A sites, tRNA (anticodon)

what happens in elongation?

complex slides over mRNA while tRNA brings in amino acids making a long chain polypeptide

what happens in termination?

-stop codon reached and protein synthesis is finished; complex falls apart

-mRNA & tRNA can be used over again, protein goes off

what are mutations?

-Can occur in either DNA or RNA

-Can be caused by mutagens, accidental exposures or spontaneously

-They can cause no effect, be harmful or cause the protein to not be made

-Types:

-Base pair substitution (point mutation)

-Frame shift mutations

what are point mutations?

alternation of a single nucleotide in a gene

what are frameshift mutations?

alter the open reading frame of a gene