Molecular Biology: Central Dogma and DNA Structure

What is the central dogma of molecular biology?

Which structure of DNA is described as the double-stranded helix?

What type of sugar is found in the structure of DNA?

Which of the following components is NOT part of a nucleotide?

What is the primary structure of DNA primarily determined by?

What are the purine bases found in nucleic acids?

What type of bond links nucleotides in a DNA strand?

What is the significance of the 5’ and 3’ ends of a nucleic acid strand?

What stabilizes the double helix structure of DNA?

Which of the following bases is not found in DNA?

What does the term 'antiparallel' refer to in the context of the DNA double helix?

What type of interaction contributes to the stability of the nitrogenous base pairing in DNA?

What distinguishes a pyrimidine from a purine in the context of nucleic acid bases?

Central Dogma of Molecular Biology

Central dogma: DNA transcribes to RNA, which translates to protein.
Fundamental principles of molecular biology explaining gene expression.

What is DNA?

Deoxyribonucleic acid (DNA) is crucial for organism development and function.
Acts as the primary unit of heredity across all organisms.

Structure of DNA

Three hierarchical levels of structure:
- Primary: nucleotide sequence.
- Secondary: double-stranded helical structure.
- Tertiary: higher-order folding for DNA packaging.

Nucleotides

Common structure: composed of sugar (deoxyribose), phosphate group, and nitrogenous base.
Carbons in sugar are numbered, crucial for understanding nucleotide connectivity.

Nitrogenous Bases

Two types of bases:
- Purines: Adenine (A) and Guanine (G).
- Pyrimidines: Cytosine (C), Thymine (T) in DNA, and Uracil (U) in RNA.

DNA Helix Structure

Composed of two coiled strands forming a double helix.
Sides are made of deoxyribose sugar linked to phosphate groups via phosphodiester bonds.
Center consists of nitrogen bases joined by weak hydrogen bonds.

Nucleotide Chain Directionality

Nucleotide sequences are represented from 5’ to 3’ direction.
Phosphodiester bonds link the 5’ phosphate of one nucleotide to the 3’ hydroxyl of another.

Watson and Crick Model

Watson and Crick developed the three-dimensional model of DNA structure.
Native DNA formed by complementary antiparallel chains.

Stability of DNA Double Helix

Stability achieved through:
- Hydrogen bonding between complementary base pairs (A-T and G-C).
- Hydrophobic interactions between stacked planar bases.

Visual Representation of DNA

Rungs of the ladder represent nitrogenous bases.
Legs of the ladder are formed from the sugar-phosphate backbone.

Explore the fundamental concepts of molecular biology focusing on the central dogma, which describes the flow of genetic information from DNA to RNA to protein. Understand the structure of DNA, including the roles of nucleotides and nitrogenous bases, as well as the double helix formation. This quiz will test your knowledge of these essential topics in molecular biology.