Cells - Ribosomes

Ribosomes are essential molecular machines in the cytoplasm where proteins are synthesized. They are not organelles as they lack a membrane. Found in all cells, ribosomes are crucial for protein production, which is vital for muscle, connective tissues, and enzymes. Proteins are chains of amino acids, with genetic instructions stored in DNA. Transcription in the nucleus copies DNA into RNA, which is processed into mRNA. This mRNA travels to ribosomes for translation into proteins. Ribosomes have two subunits: one reads mRNA, and the other forms protein chains. tRNA brings amino acids to ribosomes, matching mRNA codons to form proteins.

Where are ribosomes typically found within a cell?

• Only within mitochondria

• Exclusively on the cell membrane

• Floating freely in the cytoplasm and attached to the rough ER

• Only in the nucleus

What is the primary function of ribosomes in cells?

• To store genetic information

• To transport nutrients

• To break down waste materials

• To synthesize proteins

How is the genetic code for proteins stored in cells?

• In the cytoplasm

• In the cell membrane

• In sequences of DNA called genes

• In sequences of RNA

What is the role of mRNA in protein synthesis?

• To read the DNA sequence

• To transport amino acids to the ribosome

• To form the structure of ribosomes

• To carry the genetic instructions from DNA to the ribosome

During translation, what ensures that the correct amino acid is added to the growing protein chain?

• The ribosome's large subunit

• The matching of tRNA anticodon with mRNA codon

• The presence of free amino acids in the cytosol

• The nuclear envelope