Zusammenfassung der Ressource
Transcription & Translation
- Types of RNA
- mRNA
- single strand
- Bases - U, G, A ,C
- Synthesised from DNA
- Made in the nucleus of
Eukrayotic cells
- tRNA
- clover leaf shape
- amino acid binding
site
- complementary anticodon
to mRNA
- rRNA
- Ribosome - used in protein
synthesis
- Transcription - mRNA is
formed
- 1. DNA helicase breaks Hydrogen
bonds in DNA
- 2. RNA nucleotides bond (RNA
polymerase bonds bases)
- DNA bases - A = U, T = A. C = G, G = C
- 3. RNA polymerase moves
along DNA strand
- 4. mRNA is fully formed when
stop signal on DNA is reached
- Translation - primary sequence is
formed
- 1. mRNA joins to rRNA
- 2. Anticodon on tRNA bonds to
complementary base on mRNA
- 3. Peptide bond forms between
amino acids
- 4. Polypeptide chain is
formed when stop codon
is reached
- Introns & Exons
- Introns as non-coding bases
- Splicing pre-mRNA removes
defects and any introns
- Exons are coding bases
- Universal - same triplet in
all organisms
- Degenerate - more than 1 code for
each amino acid
- Non-overlapping - base
triplets don't share bases
- Mutations
- substitution - changing a base
for another base
- may code for same
amino acid
- Deletion - removing a base
- new amino acid
gets coded for