3.10 Protein Synthesis Flashcards
what is protein synthesis
to make a polypeptide (protein) through transcription and translation
what is an amino acid
monomer of a polypeptide (protein)
what is a peptide bond
bond that hold amino acids together
what is transcription
synthesis of an RNA molecule from a DNA template
what does DNA helicase do?
unzips DNA by breaking hydrogen bonds, beginning at a start codon
what is a sense strand
the strand of DNA that runs 5’ to 3’ and contains the genetic code for a protein
what is an antisense strand
the strand of DNA that runs 3’ to 5’ and is complementary to the sense strand. it acts as a template strand during transcription
summarise the steps of transcription
- dna double helix starts to unzip by RNA polymerase.
- once the strands of DNA separate from one another only one strand participates in the synthesis of a complementary mRNA strand
- the mRNA strand is synthesised with the help of RNA polymerase.
- after mRNA synthesis is complete, the two strands of DNA recouple and the molecules of DNA recoils to assume its double helix
summarise the steps of translation
- mRNA binds to the ribosmomes, then a tRNA carrying a specific amino acid on one end.
- Another tRNA joins to the next codon of the mRNA.
- Ribosomes catalyses the peptide bond formation
- the tRNA are released and the process repeats
what does non-overlapping genetic code mean?
when reading the sequence, it is read from base one, not two or three
what is a genetic code?
the sequences of bases in DNA that are the instruction for the sequences of amino acids in the production of proteins
what does a degenerate genetic code mean?
different combination of bases can code for the same amino acid
what are polynucleotides?
DNA and RNA
what is DNA made of?
two polynucleotide strands lying side by side, running in opposite direction
strands are held together by hydrogen bonds which can be broken easily
what is RNa
single stranded
uses uracil instead of thymine
can form a very different 3D structure
