key term - Central dogma of molecular biology

Definition

The central dogma of molecular biology is a framework that describes the flow of genetic information within a biological system. It explains how DNA is transcribed into RNA, which is then translated into proteins, highlighting the sequential processes that govern gene expression and protein synthesis. This concept is fundamental to understanding how genetic information dictates cellular functions and characteristics.

5 Must Know Facts For Your Next Test

1. The central dogma was first articulated by Francis Crick in 1957, emphasizing the directional flow of genetic information.
2. Transcription occurs in the nucleus of eukaryotic cells, where RNA polymerase synthesizes mRNA from a DNA template.
3. Translation takes place in the cytoplasm, where ribosomes read the mRNA sequence and assemble amino acids into proteins.
4. Mutations in DNA can alter the transcription and translation processes, potentially leading to changes in protein function and cellular behavior.
5. The central dogma has been expanded with discoveries like reverse transcription, where RNA can be converted back into DNA, notably seen in retroviruses.

Review Questions

• How does the central dogma illustrate the relationship between DNA, RNA, and proteins?
  • The central dogma illustrates the relationship between DNA, RNA, and proteins by outlining the sequential processes of transcription and translation. DNA serves as the genetic blueprint, which is transcribed into mRNA. This mRNA is then translated into proteins by ribosomes, showcasing how genetic information flows and ultimately results in functional molecules that perform various roles within the cell.
• Discuss the significance of mutations in DNA concerning the central dogma and their potential impact on protein synthesis.
  • Mutations in DNA are significant to the central dogma as they can lead to changes in the transcription of mRNA and subsequently affect translation. A mutation may result in an altered mRNA sequence that could produce a dysfunctional or non-functional protein. Such changes can have various effects on cellular processes and may contribute to diseases or altered traits, demonstrating how genetic integrity is crucial for proper gene expression and protein function.
• Evaluate how advancements in molecular biology have influenced our understanding of the central dogma and its exceptions.
  • Advancements in molecular biology have greatly enriched our understanding of the central dogma by revealing exceptions such as reverse transcription and RNA editing. Discoveries about retroviruses like HIV illustrate how RNA can be converted back into DNA, challenging the one-way flow initially proposed. Additionally, findings related to alternative splicing of mRNA highlight how a single gene can give rise to multiple protein products, underscoring the complexity and adaptability of gene expression beyond the traditional model of the central dogma.

Related terms

DNA replication: The process by which a cell duplicates its DNA, creating two identical copies for cell division.

Transcription: The process where the DNA sequence of a gene is copied into messenger RNA (mRNA) for protein synthesis.

Translation: The stage in protein synthesis where the mRNA sequence is decoded by ribosomes to produce a specific polypeptide chain.