Protein Synthesis and RNA Functions

Protein synthesis involves creating proteins from amino acids in cells. It consists of two main stages: transcription and translation. Transcription occurs in the nucleus, where DNA instructions are converted into messenger RNA (mRNA). RNA polymerase reads DNA base triplets to build mRNA, which then exits the nucleus. Translation occurs in the cytoplasm, where ribosomes read mRNA codons to assemble amino acids into proteins, guided by transfer RNA (tRNA) molecules. The process continues until a stop codon signals the completion of the protein, which then detaches from the ribosome.

What are proteins primarily composed of?

• Nucleotides

• Amino acids

• Lipids

• Carbohydrates

Where does the transcription stage of protein synthesis occur?

• Mitochondria

• Ribosome

• Nucleus

• Cytoplasm

What is the role of RNA polymerase during transcription?

• It splices exons together

• It reads DNA base triplets to build mRNA

• It assembles amino acids into proteins

• It transports mRNA to the ribosome

What replaces thymine in mRNA?

• Uracil

• Guanine

• Adenine

• Cytosine

What happens to introns during mRNA processing?

• They are duplicated

• They are converted into exons

• They are removed by enzymes

• They are translated into proteins

Where does the translation stage of protein synthesis occur?

• Golgi apparatus

• Cytoplasm

• Endoplasmic reticulum

• Nucleus

What structure reads the mRNA during translation?

• Nucleus

• Ribosome

• Lysosome

• Mitochondria

What signals the start of protein assembly on the ribosome?

• Exon

• Anticodon

• Start codon

• Stop codon

What is the role of transfer RNA (tRNA) during translation?

• It synthesizes mRNA

• It carries amino acids to the ribosome

• It removes introns from mRNA

• It forms the ribosome structure

What signals the end of protein synthesis on the ribosome?

• Start codon

• Exon

• Stop codon

• Anticodon