Module 7: 4/17/2023

Question 1

Central Dogma of Molecular Biology

Answer 1

The Flow of Information in the Cell
1. DNA strand (template)
2. TRANSCRIPTION
3. mRNA: Made up of Codons (each codon codes for a protein)
4. TRANSLATION
5. Protein

Question 2

Frederick Griffith: Griffith Streptococcua pneumoniae

Answer 2

• Began discovery of genetic role of RNA
• Describes “transforming parricle”
• Used bacterial model

Question 3

Avery, Macleod, McCarthy (1944)

Answer 3

• Used only each of the candidates for instruction (RNA, Protein, DNA, Lipid, Carbohydrate)
• Molecules tested for transformation of R-strain cells
• DNA = S-strain
• Conclusion: DNA is the transforming principle

Question 4

Hershey and Chase Experiment: Bacteriophage

Answer 4

• Viruses consist of DNA (or RNA) enclosed by a protective coat of protein
• Showed that DNA was the genetic material of the T2 phage
• Virus that infects Escherichia coli (bacteria)

Question 5

T4 Phage Infection

Answer 5

1. Absorption: Phage attaches onto bacterial cell wall
2. Penetration: Inject viral DNA into Bacterial cell
3. Bacterial DNA is disrupted (chromosomes destroyed, only viral DNA gets made)
4. Biosynthesis: Phage DNA directs cell metabolism to produce viral components (proteins and copies of phage DNA)
5. Maturation

Question 6

Hershey and Chase Experiment, 1952

Answer 6

1. Protein coats of phages are radioactively labeled (radioactive sulfur)
2. Phages infect bacteria with genetic material
3. No radioactivity enters cells
4. DNA of phages is radioactibely labeled (radioactive phosphorous)
5. Phages infect bacteria with genetic material
6. Radioactivity enters cell

Question 7

From Gene to Protein

Answer 7

• Specific sequence of nucleotides in each gene carries the information for the primary structure of proteins
• To get from DNA (nucleic acids), to protein (amino acids) requires two major stages: TRANSCRIPTION AND TRANSLATION

Question 8

Transcription

Answer 8

Process of making RNA
* DNA code (string of nucleotides) serves as TEMPLATE

Question 9

Coding RNA

Answer 9

Messenger RNA (mRNA)

Question 10

Non-Coding RNA

Answer 10

1. Ribosomal RNA (structural)
2. Transfer RNA (tRNA, structural, brings amino acids to ribosomes)
3. Small Nuclear RNA (snRNA, Gene regulation, control elements that help turn genes on or off)
4. Micro-RNA (miRNA, Gene regulation, control elements that help turn genes on or off)