DNA, RNA & Protein Synthesis Practice Quiz

The central dogma describes the flow of genetic information from DNA to RNA and then to protein. This framework is fundamental to understanding molecular biology.

Transcription is the process by which RNA is synthesized using DNA as a template. It is essential for the expression of genetic information.

Helicase unwinds the DNA double helix, separating the two strands to allow replication. This action is a crucial early step in DNA replication.

Ribosomes are the cellular organelles where proteins are synthesized during translation. They read the mRNA sequence and string together amino acids accordingly.

In DNA, adenine pairs with thymine through hydrogen bonding. This specific pairing helps maintain the structure and fidelity of the DNA double helix.

RNA polymerase is the enzyme that catalyzes the addition of ribonucleotides during transcription. It reads the DNA template and synthesizes the corresponding RNA strand.

The promoter region is a specific DNA sequence that signals RNA polymerase where to start transcription. It plays a key role in regulating gene expression.

DNA polymerase is responsible for adding nucleotides to form a new DNA strand during replication. It ensures that the new strand is complementary to the template strand.

Messenger RNA (mRNA) carries genetic information from the nucleus to the cytoplasm. It serves as a template during the process of translation.

Transfer RNA (tRNA) carries specific amino acids to the ribosome during protein synthesis. Each tRNA recognizes a specific codon on the mRNA, ensuring proper assembly of the amino acid chain.

Ribosomal RNA (rRNA) plays a catalytic role in forming peptide bonds between amino acids. Its presence in the ribosome is essential for the accurate synthesis of proteins.

During the elongation phase, the ribosome moves along the mRNA, and amino acids are sequentially joined together to form a polypeptide chain. This phase is critical for building the protein based on the mRNA sequence.

RNA contains uracil in place of thymine, which is found in DNA. This difference is one of the key distinctions between RNA and DNA molecules.

DNA ligase seals the nicks between Okazaki fragments on the lagging strand by forming phosphodiester bonds. This enzyme is essential for creating a continuous DNA strand during replication.

DNA replication is the process of copying the entire genome prior to cell division. In contrast, transcription selectively copies segments of DNA into RNA for gene expression.

The 5' cap and poly-A tail are important modifications that stabilize mRNA molecules and enhance their translation by aiding ribosome recognition. They also protect the mRNA from enzymatic degradation.

Antisense RNA binds to its complementary mRNA sequence, which can block ribosome binding and prevent translation. This mechanism is an important means of regulating gene expression.

Frameshift mutations are generally caused by the insertion or deletion of nucleotides, which alter the reading frame of the gene. This disruption often results in a nonfunctional protein.

The start codon, typically AUG, is crucial because it sets the reading frame for translation. This ensures that the subsequent amino acid sequence is translated correctly.

DNA polymerase possesses proofreading ability, which corrects errors during DNA replication. This high level of fidelity is critical for maintaining genetic stability across cell divisions.