Molecular Basis of Genetics

Based on what was stated in the video lecture only, and not purely based on the pdf given to us.

What is the Molecular Basis of Genetics or Inheritance?

Deoxyribonucleic Acid (DNA)

DNA can be found in what?

Nucleus and Mitochondria of Animal Cells

What is the main function of DNA?

ENCODING. Encodes the genetic makeup of most organisms and is thus considered to be the Central Molecule of Life.

A theory which states that genetic information flows ONLY IN ONE DIRECTION.

Central Dogma of Molecular Biology

Central Dogma of Molecular Biology states that…

Genetic Information flows only in one direction.

What are the 3 Steps or Phases of Central Dogma of Molecular Biology?

1. Replication

2. Transcription

3. Translation

A step in central dogma where it ensures that the genetic information is transferred from Parent to Offspring.

Replication

A step in central dogma where the genetic information carried by DNA is transcribed into an RNA.

Transcription

A step in central dogma where the information carried in Messenger RNA [mRNA] is translated into proteins, which carry out the work necessary to sustain life.

Translation

TRUE OR FALSE

The Theory of Central Dogma is Unidirectional at all times.

False. The theory is accepted and true to humans, but Viruses (Retrovirus) is an exception.

Why is the Retrovirus an exception to the Theory of the Central Dogma being Unidirectional?

It is because it has an enzyme called Reverse Transcriptase, which is capable to convert its RNA back to DNA, also known as Reverse Transcription.

Structure of DNA

Double Helix

It contains 2 strands of poly deoxyribonucleotides and is held together by noncovalent interactions between purine and pyrimidine bases. What is it?

DNA

State the Purine Bases and Pyrimidine Bases in DNA and RNA, and their Base Pairing.

• DNA

  • Purine: Adenine, Guanine

  • Pyrimidine: Cytosine, Thymine

  • Pairing: AT - GC

• RNA

  • Purine: Adenine, Guanine

  • Pyrimidine: Cytosine, Uracil

  • Pairing: AU - GC

The two strands in the double helix structure of DNA are arranged in ___ [ __ ], such that one strand runs in the 5’ → 3’ direction, whereas the other runs in the 3’ → 5’ direction

Opposite Orientations [Antiparallel]

Three [3] Key Features of Eukaryotic DNA Replication.

1. DNA replication is Semiconservative

2. DNA replication is Bidirectional

3. DNA is synthesized in the 5’ → 3’ direction and is Semi Discontinuous.

DNA replication is Semiconservative. It involves the independent replication of each parental DNA strand so that the resulting Two DNA molecules each contain one ___ and one newly synthesized ___.

Parental Strand, and Daughter Strand.

DNA replication is Bidirectional. Replication in Eukaryotes starts at many points along the linear DNA double helix. What are these points called?

Origins of Replication

It is a single stranded polymer of ribonucleotides and instead of having Thymine, it has Uracil. What is it?

Ribonucleic Acid (RNA)

Three [3] Different Types of RNA

1. Ribosomal RNA

2. Transfer RNA

3. Messenger RNA

Type of RNA which mainly functions for protein synthesis. These represent 80% of total cellular RNA and are Long-Lived.

Ribosomal RNA (rRNA)