Zusammenfassung der Ressource
Protein Synthesis
- Proteins info
- Made of amino acids. A chain
of which is called a
polypeptide. Peptide bonds
hold them together
- Two types: fibrous and
globular. Fibrous form
bundles and globular are
folded into globe-shaped
molecules
- Made up of
several thousand
amino acids
- RNA
- messenger, transfer
and ribosomal
- Single stranded
- Sugar is ribose
- The base Uracil
replaces Thymine
- Transcription
- 1) The enzyme RNA polymerase
binds to the strand and the DNA
unwinds here. The enzyme Helicase
does this.
- 2) Only one strand is used
and the triplets are read by an
enzyme and are corresponded
into codons.
- 3)When RNA polymerase
reaches the terminator
sequence, transcription
is completed.
- 4) The two DNA strands
rejoin
- Occurs in nucleus
- RNA Splicing: Introns are NOT
needed for the protein formation so
these are cut out of the strand. The
exons are then joined together to
from the final transcript of mRNA.
- Translation
- 1) The edited mRNA
leaves the nucleus and
travels to a ribosome.
- 2) The ribosome
moves along the
mRNA strand and
reads the codons.
- 3) Each codon corresponds to a triplet in DNA,
thus coding for a particular amino acid.
- 4) The corresponding tRNA molecule
brings along the anti-codon and picks up
the correct amino acid along the way.
- 5) This continues until a STOP
codon is reached and translation
terminates. The amino acids
have now formed a chain and it
breaks off and travels to the
place it's needed.
- Occurs in cytoplasm
and ribosomes