Genetic Code and Protein Synthesis

What does tRNA do in protein synthesis?

Transfers amino acids to the ribosome to create proteins.

What is the role of rRNA in ribosomes?

Forms the core structural and functional components of ribosomes.

What is transcription?

The process of synthesizing mRNA from a DNA template.

What is the enzyme responsible for transcription?

RNA polymerase.

What are introns and exons?

Introns are noncoding segments of RNA, while exons are coding segments that contain information for making proteins.

What happens during RNA splicing?

Introns are removed, and exons are joined together to form the mature mRNA.

What is a codon?

A three-base sequence in mRNA that corresponds to a specific amino acid.

What does the start codon AUG code for?

Methionine, the first amino acid in protein synthesis.

What types of mutations can occur in DNA?

Substitution, deletion, and addition mutations.

What is a point mutation?

A mutation where a single base pair is substituted for another.

Give an example of a disease caused by a point mutation.

Sickle Cell Anemia.

What is a frameshift mutation?

A mutation that alters the reading frame of the genetic message, usually due to insertion or deletion.

What are mutagens?

Environmental factors that can cause mutations.

What are carcinogens?

Mutagens that specifically cause cancer.

What is the role of a release factor in translation?

Binds to the stop codon and triggers the release of the completed protein.

What occurs during the elongation stage of translation?

Amino acids are added to the growing polypeptide chain as tRNAs bring in new amino acids.

What is the final result of protein synthesis?

A newly formed protein that is then used for its specific function.

What happens to the mRNA after translation?

It may be destroyed or reused for further protein synthesis.

What is the significance of redundant codons?

Multiple codons can code for the same amino acid, which can help prevent the effects of mutations.

What are the steps of transcription?

1. Initiation: RNA polymerase binds to the promoter region on DNA. 2. Elongation: RNA polymerase synthesizes mRNA by adding complementary RNA nucleotides. 3. Termination: RNA polymerase reaches a termination signal and releases the mRNA transcript.

What does RNA polymerase do during transcription?

RNA polymerase is the enzyme that synthesizes mRNA from a DNA template during transcription.

What are mutagens and how do they affect DNA?

Mutagens are environmental factors that can cause changes in the DNA sequence, leading to mutations.

What are the types of mutations in DNA?

Substitution, deletion, insertion, and frameshift mutations.

What is the difference between substitution and frameshift mutations?

Substitution mutations replace one base in the DNA sequence, while frameshift mutations involve insertion or deletion of bases, altering the reading frame.

What are silent mutations?

Mutations that do not change the amino acid sequence of a protein due to redundancy in the genetic code.

What is a missense mutation?

A mutation that results in the substitution of one amino acid for another in a protein.

What is the structure of RNA?

RNA is a single-stranded nucleic acid made up of ribonucleotides containing a ribose sugar, phosphate group, and nitrogenous bases (adenine, uracil, cytosine, guanine).

What is the primary function of mRNA?

To carry the genetic information from DNA to the ribosome for protein synthesis.

What are the key differences between RNA and DNA?

RNA is single-stranded and contains uracil instead of thymine, while DNA is double-stranded and contains thymine.

What is the significance of complementary base pairing in RNA?

Complementary base pairing (adenine with uracil, and cytosine with guanine) ensures accurate transcription and translation.

What is the structure of tRNA and its function?

tRNA is a cloverleaf-shaped molecule that brings specific amino acids to the ribosome during protein synthesis.

What role do ribosomes play in protein synthesis?

Ribosomes serve as the site for translation where mRNA is read and amino acids are assembled into proteins.