Ribosomes Flashcards
(5 cards)
What are the main components of the protein synthetic machinery of the cell?
The protein synthetic machinery of the cell is composed of ribosomes, polyribosomes, endoplasmic reticulum, and the Golgi apparatus.
What are ribosomes made of?
Ribosomes are small non-membranous particles composed of protein and ribosomal RNA (rRNA).
How are ribosomal subunits structured?
Each ribosome consists of a large subunit and a small subunit. The small subunit contains 33 proteins and 18S rRNA, while the large subunit comprises 49 proteins and 3 rRNA.
What functional sites are present on the small ribosomal subunit?
The small ribosomal subunit has a site for binding mRNA, a P-site for peptidyl tRNA, and an A-site for binding aminoacyl tRNAs.
Where are ribosomal subunits assembled and what happens before protein synthesis begins?
Ribosomal subunits are assembled in the nucleolus and released into the cytoplasm as separate entities, not forming ribosomes until protein synthesis begins.
