Molecular Biology Overview and History

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Who shared the 1962 Nobel Prize in Physiology and Medicine for their proposed structure of DNA?

  • Seymour Benzer
  • George Gamow
  • Francis Crick & James Watson (correct)
  • Charles Yanofsky

What concept did Seymour Benzer define in his work with phage genetics?

  • Cistron (correct)
  • Allele
  • Gene
  • Genotype

What was the focus of George Gamow's informal group known as the RNA Tie Club?

  • Gene mutation
  • The genetic code (correct)
  • Protein synthesis
  • The structure of RNA

What did Charles Yanofsky prove about the relationship between genes and nucleotides?

<p>There is collinearity of the gene. (B)</p> Signup and view all the answers

Which method did Seymour Benzer use to study genetic mutations?

<p>Functional complementation tests (D)</p> Signup and view all the answers

What major realization came from Seymour Benzer's studies on mutations?

<p>Mutations can occur at the level of a single nucleotide. (D)</p> Signup and view all the answers

What field of study was significantly advanced by the work of Crick and Watson?

<p>Molecular biology (A)</p> Signup and view all the answers

What was the key outcome of the 1966 Symposium on The Genetic Code?

<p>Establishing the correspondence between coding sequence and amino acids (A)</p> Signup and view all the answers

What is the main function of terminal transferase in DNA synthesis?

<p>To synthesize polynucleotide chains without a template (D)</p> Signup and view all the answers

How do exonucleases differ from endonucleases?

<p>Exonucleases act on free 3' or 5' ends, while endonucleases act on the backbone (D)</p> Signup and view all the answers

What role do restriction enzymes play in genetic engineering?

<p>To recognize specific base sequences and break DNA (D)</p> Signup and view all the answers

What is a significant characteristic of helicases?

<p>They cut and re-close DNA to prevent tangling (C)</p> Signup and view all the answers

Which of the following describes the function of topoisomerases?

<p>To relieve torsional strain during DNA replication (B)</p> Signup and view all the answers

How do nucleases generally function in DNA metabolism?

<p>They modify and digest foreign DNA (C)</p> Signup and view all the answers

What is a characteristic of endonucleases?

<p>They break the sugar-phosphate backbone of DNA (A)</p> Signup and view all the answers

Which of the following statements about DNA polymerization is true?

<p>DNA polymerized by enzymes can be modified post-synthesis (A)</p> Signup and view all the answers

What is the primary structure of protein characterized by?

<p>The sequence of amino acids (A)</p> Signup and view all the answers

Which structure of protein is determined by the folding of the polypeptide chain into a 3D shape?

<p>Tertiary Structure (D)</p> Signup and view all the answers

What are nonsense codons?

<p>Codons that terminate protein synthesis (B)</p> Signup and view all the answers

What was the significance of the work done by Harriet Creighton and Barbara McClintock in 1931 regarding eye color?

<p>They provided evidence that eye color is sex-linked. (D)</p> Signup and view all the answers

How can mutations in DNA affect phenotype?

<p>They may cause changes in the amino acid sequence affecting function. (B)</p> Signup and view all the answers

Which scientist contributed to the understanding of the structure of DNA in 1953?

<p>James Watson (C)</p> Signup and view all the answers

What are conjugated proteins defined by?

<p>Having additional nonprotein components (A)</p> Signup and view all the answers

What are oligomers in protein structure?

<p>Proteins composed of multiple polypeptide chains that work together (C)</p> Signup and view all the answers

Which hypothesis was proposed by George Beadle and E.L. Tatum in 1941?

<p>Genes control enzymes on a one-to-one basis. (C)</p> Signup and view all the answers

What is the role of codon selection in protein synthesis?

<p>To differentiate between human tissues and diseases (D)</p> Signup and view all the answers

What major discovery was made by Hamilton Smith in 1970?

<p>The discovery of restriction enzymes. (A)</p> Signup and view all the answers

Which of the following correctly describes the work done by Meselson and Stahl in 1958?

<p>They demonstrated semiconservative replication of DNA. (C)</p> Signup and view all the answers

Which of the following is a characteristic of primary structure in proteins?

<p>It determines the protein's functionality (B)</p> Signup and view all the answers

What does the term 'sex-linked' refer to in genetics?

<p>Traits that are carried on the X or Y chromosomes. (C)</p> Signup and view all the answers

What was the main contribution of Marshall Nirenberg and Gobind Khorana in 1966?

<p>They unraveled the genetic code. (D)</p> Signup and view all the answers

In what year did Oswald Avery, Colin McLeod, and Maclyn McCarty identify DNA as the genetic material?

<p>1944 (B)</p> Signup and view all the answers

Who is credited with coining the term 'molecular biology'?

<p>James Watson (A)</p> Signup and view all the answers

What was identified as the genetic material in the 1940s?

<p>Deoxyribonucleic acid (DNA) (C)</p> Signup and view all the answers

What is the primary focus of molecular biology?

<p>Structure and function of the gene (A)</p> Signup and view all the answers

What phenomenon did Frederick Griffith describe as the 'transforming principle'?

<p>Transformation of bacteria (D)</p> Signup and view all the answers

Which of the following fields has benefited from advancements in molecular biology?

<p>Agriculture (B)</p> Signup and view all the answers

What major discovery was made regarding nucleic acids in 1953?

<p>The biochemical structure of DNA (B)</p> Signup and view all the answers

What is one key application of molecular biology in medicine?

<p>Diagnostics for diseases such as cancer (D)</p> Signup and view all the answers

Which researchers reported that DNA is the hereditary material in 1944?

<p>Avery, MacLeod, and McCarty (C)</p> Signup and view all the answers

Flashcards are hidden until you start studying

Study Notes

Molecular Biology: Overview

  • Molecular biology is the study of biomolecules and how they function in living organisms.
  • Focuses on the structure and function of genes, including replication, mutation, repair, and expression.

History of Molecular Biology

  • 1859: Charles Darwin publishes "On the Origin of Species".
  • 1869: Friedrich Miescher discovers "nuclein" (nucleic acids).
  • 1928: Frederick Griffith identifies DNA as the "transforming principle" responsible for genetic transformation.
  • 1944: Oswald Avery, Colin MacLeod, and Maclyn McCarty prove that DNA, not protein, carries the hereditary material.
  • 1953: James Watson and Francis Crick elucidate the structure of DNA.
  • 1958: Matthew Meselson and Franklin Stahl demonstrate the semiconservative replication of DNA.
  • 1961: Sydney Brenner and François Jacob discover messenger RNA (mRNA).
  • 1966: Marshall Nirenberg and Gobind Khorana unravel the genetic code.
  • 1970: Hamilton Smith discovers restriction enzymes, crucial for DNA cloning.

Key Concepts of Molecular Biology

  • Gene: A sequence of nucleotides on a chromosome that encodes a functional product.
  • Genetic Code: The set of rules relating DNA sequences to amino acid sequences in proteins.
  • Codon: A three-nucleotide sequence that codes for a specific amino acid.
  • Translation: The process of converting mRNA into protein.
  • Amino Acid Charging: The process of attaching a specific amino acid to its corresponding tRNA.

The Francis Crick & James Watson Story

  • Worked together to propose the structure of DNA, for which they received the 1962 Nobel Prize in Physiology and Medicine.

Seymour Benzer: Phage Genetics Research

  • Studied phage genetics, defining the smallest unit of mutation as a single nucleotide.
  • His work also provided an experimental definition of the "gene" as a "cistron" through functional complementation tests.

George Gamow's RNA Tie Club

  • A physicist interested in the genetic code.
  • Founded an informal group of scientists to study this problem.

Charles Yanofsky: Gene Collinearity

  • Demonstrated the collinearity of the gene, meaning successive groups of nucleotides encode successive amino acids in a protein.

Other Important Figures in Molecular Biology

  • Harriet Creighton and Barbara McClintock: Provided physical evidence for recombination in 1931.
  • George Beadle and E.L. Tatum: Proposed the one-gene/one-enzyme hypothesis in 1941.

Importance of Molecular Biology

  • It has led to advancements in various fields, including agriculture, medicine, and forensics.
  • Plays a crucial role in diagnostics, developing tests for diseases like cancer.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

More Like This

Use Quizgecko on...
Browser
Browser