Protein Synthesis Overview
Protein synthesis is a cellular process, converting genetic information into functional proteins. It involves transcription in the nucleus and translation at the ribosomes, turning DNA code into life’s building blocks.
Genetic Code Uniqueness
The genetic code is nearly universal, shared by the simplest bacteria to the most complex animals. This hints at a common evolutionary origin. Surprisingly, a few organisms have slight variations, challenging the universality concept.
Transcription's Detailed Mechanics
During transcription, RNA polymerase reads DNA, synthesizing messenger RNA (mRNA). Intriguingly, only one DNA strand serves as a template, and the process includes elaborate unwinding and rewinding of the DNA helix.
Translation and tRNA
Transfer RNA (tRNA) molecules play a pivotal role in translation. Each tRNA has an anticodon matching mRNA codons and carries a specific amino acid, ensuring the correct protein sequence is synthesized.
Ribosomes: Protein Factories
Ribosomes may seem uniform, but they differ between domains of life. Bacterial ribosomes are smaller (70S) than eukaryotic (80S), making them targets for antibiotics without affecting human ribosomes.
Post-Translational Modifications
After initial synthesis, proteins undergo post-translational modifications. This can include folding, cutting, or adding chemical groups, crucial for function and regulation. Some modifications are so complex, they're not yet fully understood.
Genetic Code Redundancy
The genetic code is redundant, with multiple codons encoding the same amino acid. This redundancy can reduce the impact of mutations, providing a buffer against genetic errors and potential diseases.
Where does protein synthesis begin?
In the nucleus with transcription
At ribosomes with translation
Within mitochondria with DNA replication
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