Molecular Biology Course Notes

Course Code: MPRM0107
Course Title: Molecular Biology
Course Credits: 3 Credit hours
Course Duration: 17 Weeks
Course Coordinator: Dr. Souad Al-Okla
- Affiliation: College of Medicine and Health Sciences

Goal: The course provides details on molecular processes within the cell with a focus on the structure and function of nucleic acids, their regulation, and the introduction of molecular biology techniques.
Course Description:
- Discusses nucleic acid structure, function, replication, damage, repair, and gene expression control.
- Covers various molecular and biochemical techniques for isolating, replicating, and analyzing nucleic acid sequences, along with applications in the diagnosis, prognosis, and management of human diseases.

Exams:
- In-Course Exam: 40 MCQs (30% weightage)
- Final Exam: 50 Questions, including MCQ, True/False, and Matching (40% weightage)
Continuous Assessments:
- Quiz 1: 15 MCQs (7.5% weightage)
- Quiz 2: 15 MCQs (7.5% weightage)
- Self-Directed Learning (SDL) Presentation: Exploring Gene Mutations and Genetic Diseases (5% weightage)
- Concept Map Submission: Exploring Genomic Imprinting (5% weightage)
- Task-Based Learning (TBL): Collaborative Learning on Air Pollution's Impact on Human Health (5% weightage)

SLO 1: Recognize contributions of historical figures (Chargaff, Franklin, Wilkins, Watson, and Crick) in understanding DNA structure.
SLO 2: Describe the biochemical structure of ribonucleotides that compose DNA.
SLO 3: Explain the DNA structure, including strands, polarity (5’-3’), complementary strands, and their anti-parallel nature.

Replication: DNA copies itself.
Transcription: DNA instruction is transcribed to mRNA.
Translation: mRNA translates the message to proteins.
Directionality of Information Flow:
- From DNA to RNA to Protein
- Not reversible in nature: DNA 1; RNA 1; Protein, while in labs it can be reversed.
DNA Location: DNA remains in the nucleus for protection, as it contains crucial instructions for body growth and functions.

Deoxyribonucleic Acid (DNA):
- The molecular basis for inheritance. Encodes hereditary information in the chemical language of DNA.
- Functions analogous to a computer program, controlling the development of traits.
- DNA is copied in all cells, ensuring uniform instructions for cellular functions.

Early 20th Century: Major challenge for biologists to identify the hereditary molecule.
Studies on Bacteria and Viruses: Initial determinations that DNA carries hereditary information through studies on bacteria and bacteriophages.
- Frederick Griffith's Experiment: Key findings included transformation demonstrating living R bacteria could become pathogenic S bacteria via a heritable substance from dead S cells.
- Specific experimental results:
- Living S (control) cells: Mouse dies.
- Living R (control) cells: Mouse healthy.
- Heat-killed (control) S cells: Mouse healthy.
- Mixture of heat-killed S and living R cells: Mouse dies.

Alfred Hershey and Martha Chase Experiment:
- Method: DNA labeled with ^{32}P and protein labeled with ^{35}S.
- Findings: In infected bacteria, only ^{32}P was found, proving that DNA is the genetic material.
Erwin Chargaff's Analysis: Established that DNA composition varies by species, leading to the conclusion that DNA is a strong candidate for genetic material, further supported by his rules:
- T ext{%} = A ext{%} (Thymine approximately equals Adenine)
- G ext{%} = C ext{%} (Guanine approximately equals Cytosine)

DNA is a polymer made of nucleotides, which include a sugar-phosphate backbone and nitrogenous bases.
DNA Nucleotide Composition:
- Comprised of purines (Adenine, Guanine) and pyrimidines (Cytosine, Thymine).
- Formation of polynucleotide chains through phosphodiester linkages.
DNA Structure:
- DNA double helix formed by two antiparallel sugar-phosphate backbones with nitrogenous base pairs inside.
- Each base pair has specific pairing rules:
- Adenine pairs with Thymine (two hydrogen bonds).
- Guanine pairs with Cytosine (three hydrogen bonds).
Conformation:
- The double helix has major and minor grooves, with a diameter of 2 nm and specific helical turns of 0.34 nm between base pairs.

DNA serves as the molecular blueprint for inheritance, composed of nucleotide monomers linked together to form chains. Nucleotide chain structure consists of complementary sequences that form the double helix, essential for genetic information storage and transfer across generations.