Protein Synthesis Flashcards
give 4 structure features of prokaryotic DNA
- circular
- not associaed with histones
- does not contain introns
- short
give 4 structure features of eukaryotic DNA
- linear
- associated with histones
- contains introns
- very long
what is a gene
sequence of DNA bases that codes for a polypeptide
what is the position of a gene called
locus
what are exons
code for a specific sequence of amino acids in the primary structure
what are introns
do not code for a specific sequence of amino acids in the primary structure
true or false
prokaryotic DNA contains introns
false
where is non coding DNA found
between genes
what is genome
all the DNA in a cell
what is proteome
the full range of proteins produced by cells
in DNA what is a sequence of three bases called
triplet
how much bases code for an amino acid
3
during protein synthesis, the DNA triplets are transcribed into ….
mRNA codons
give 3 features of the genetic code and explain them
- universal = the same 3 bases code for the same amino acids in all organisms
- non overlapping = each base is read only once in the triplet
- degenerate = more than one triplet that codes for a single amino acid
what is the structure of mRNA
- single stranded
- linear
- short
what is the structure of tRNA
- single stranded
- folded into cloverleaf shape by hydrogen bonds beween complementary base pairs
- smaller than mRNA
give 2 structure differences between mRNA and tRNA
- mRNA is linear whereas tRNA is in a cloverleaf shape
- tRNA is smaller
- tRNA has anticodons whereas mRNA has codons
describe the process of transciption
- DNA helicase breaks hydrogen bonds between base pairs
- one DNA strand acts as a template
- free RNA nucleotides align by complemntary base pairing
- uracil is used instead of thymine
- RNA plymerase joins adjacent RNA nucleotides together by phosphodiester bonds
eukaryotes only:
- pre mRNA is spliced and introns are removed
describe the process of translation
- mRNA attaches to the ribosome
- tRNA brings a specific amino acid to the ribosome
- tRNA anticodons bind to complementary mRNA codons
- amino acids are joined by peptide bonds which is catalysed by the ribosome
- the joining of these peptide bonds requires energy releases from ATP hyrolysis
- tRNA is released after amino acids are joined to the polypeptide
- the ribosome moves along the mRNA to form the polypeptide
suggest advanatges of using mRNA rather than DNA for translation
- shorter - breaks down quickly
- single stranded and linear - ribosome moves along strand
- contains no introns
where does transcription take place
nucleus
where does translation take place
cytoplasm
