What is the function of ribosomes in a cell?
A.
To produce energy for the cell
B.
To store genetic information
C.
To transport molecules within the cell
D.
To synthesize proteins in the cell
The Correct Answer and Explanation is:
The correct answer is D. To synthesize proteins in the cell.
Explanation:
Ribosomes are essential cellular organelles found in all living cells, both prokaryotic and eukaryotic. Their primary function is to synthesize proteins, which are crucial for numerous cellular functions and overall cellular health.
- Structure and Location: Ribosomes consist of two subunits: a large subunit and a small subunit, each composed of ribosomal RNA (rRNA) and proteins. In eukaryotic cells, ribosomes can be found either floating freely in the cytoplasm or attached to the endoplasmic reticulum, creating what is known as rough ER. In prokaryotic cells, ribosomes are dispersed throughout the cytoplasm since they lack membrane-bound organelles.
- Protein Synthesis: Ribosomes play a central role in protein synthesis, a process known as translation. During translation, ribosomes read the genetic information encoded in messenger RNA (mRNA) sequences. The mRNA, which was transcribed from DNA in the nucleus (in eukaryotes), carries the code that determines the sequence of amino acids in a protein. Ribosomes facilitate the binding of transfer RNA (tRNA) molecules, each carrying a specific amino acid, to the corresponding codon on the mRNA strand. This process results in the formation of a polypeptide chain that folds into a functional protein.
- Protein Function: Proteins synthesized by ribosomes are involved in virtually every cellular process. They act as enzymes, structural components, signaling molecules, and more. For example, enzymes catalyze biochemical reactions, structural proteins contribute to the cell’s shape and integrity, and signaling proteins help in communication between cells.
- Translation Process: During translation, ribosomes ensure the correct sequence of amino acids by matching tRNA anticodons with mRNA codons. This precision is crucial for producing functional proteins that perform specific tasks within the cell, from muscle contraction to immune response.
In summary, ribosomes are critical for translating genetic information into proteins, which are vital for the growth, repair, and maintenance of cells and the overall functioning of organisms.