Ribosomes Flashcards
Where do free ribosomes float?
In the cytoplasm
Free ribosomes are present in both eukaryotic and prokaryotic cells.
What are bound ribosomes attached to?
Rough endoplasmic reticulum and they are not found in prokaryotic cells
Bound ribosomes are not found in prokaryotic cells.
What two components make up ribosomes?
rRNA and ribosomal proteins forming subunits
Ribosomes consist of two subunits: a small subunit and a large subunit.
What is the function of the small subunit of a ribosome?
Decodes mRNA
The small subunit plays a crucial role in translation by binding to the mRNA strand.
What is the function of the large subunit of a ribosome?
Facilitates the formation of amino acid chains
The large subunit helps in the assembly of polypeptides during protein synthesis.
What percentage of ribosomes is composed of RNA?
62%
The remaining portion consists of proteins.
What do free ribosomes produce proteins for?
Used in the cytoplasm
These proteins are typically enzymes or structural proteins required by the cell.
What do bound ribosomes produce proteins for?
Incorporated into the cell membrane, secreted from the cell, or packed into organelles
These proteins often function in cellular processes and interactions.
What are the three main steps of translation?
Initiation, Elongation, Termination
Each step is crucial for the accurate synthesis of proteins.
What occurs during the initiation phase of translation?
Small ribosomal subunits bind to mRNA strand at the beginning of the codon
This step is essential for the correct start of protein synthesis.
What happens during the elongation phase of translation?
Reads the codons of the mRNA and adds the corresponding tRNA to create a polypeptide chain
This phase involves the sequential addition of amino acids to the growing polypeptide.
What occurs during the termination phase of translation?
Protein is released when ribosomes reach a stop codon
This signals the end of protein synthesis, releasing the completed protein.
What are the two types of ribosomes?
Free ribosomes and Bound ribosomes
What is the function of ribosomes?
They are the site of protein synthesis through Translation
