Unit 2: Molecular Biology and Genetic Engineering
BIO2 – 11 Lesson 2: DNA Replication & Protein Synthesis Overview
Lesson 2.2
DNA Replication and Protein Synthesis
Contents
Introduction 1
Learning Objectives 2
Warm Up 3
Learn about It! 4
The Replication of DNA 5
The Semiconservative Nature of DNA Replication 5
The General Mechanism of Replication 8
The Origin of Replication 9
Initiation of Replication 10
The Action of Polymerase during Elongation 12
Termination of Replication 14
DNA Proofreading and Repair 15
Eukaryotic Replication 15
The Central Dogma of Molecular Biology 16
Types of RNAs 17
The General Mechanism of Transcription 18
Initiation of Transcription 19
Elongation in Transcription 21
Termination of Transcription 22
Post-transcriptional Modifications 22
Overview of Translation and the Genetic Code 23
The Players during Translation 25
Mechanism of Translation 26
Post-translational Modifications 28
Key Points 29
Check Your Understanding 32
Challenge Yourself 34
Bibliography 34
,
,Unit 2: Molecular Biology and Genetic Engineering
Lesson 2.2
DNA Replication and Protein
Synthesis
Introduction
Have you had any form of bacterial or viral infection? Did you seek your doctor for a
consultation? In many cases, conditions can get better even without medications. However,
for more serious cases such as in herpes and HIV infection, further proliferation of the viruses
must be controlled. The mechanism of action of antivirals targets one crucial aspect of life—
reproduction. Reproduction entails various modes that allow the genetic material to be
transmitted from parents to offspring or progenitors. For cellular entities, reproduction
begins with the division of a cell. For a cell to divide, part of its preparation is
2.2. DNA Replication and Protein Synthesis 1
, Unit 2: Molecular Biology and Genetic Engineering
the creation of copies of its genetic material to ensure that all successive generations of cells
will have a complete set of genetic information. This is when antivirals come into action—
they prevent the synthesis of the genetic material. For example, acyclovir, a type of antiviral
drug against herpes simplex virus, targets the molecular machinery that creates copies of
DNA. This then prevents further proliferation and spread of the virus in the affected
individual.
The genetic information in cells is highly conserved and protected. Just as bacteria and
viruses perform an efficient way of creating copies of their genetic information to reproduce,
so are the cells of more complex organisms. In addition to the importance of DNA duplication,
the information must also be expressed as the traits of organisms required for maintenance
and survival. Similar to the file conversion we usually perform in our computers, the
information in DNA must be copied in an alternate version first before finally producing the
functional products. It is not used directly when synthesizing polypeptides. In this chapter,
we will look at the intricate molecular machinery that performs the replication and expression
of genetic information.
Learning Objectives Competency
In this lesson, you should be able to do the
Diagram the steps in DNA
following: replication and protein synthesis
● Explain the process of DNA replication. (STEM_BIO11/12-IIIa-b-5).
● Explain the processes involved in
transcription and translation.
2.2. DNA Replication and Protein Synthesis 2
BIO2 – 11 Lesson 2: DNA Replication & Protein Synthesis Overview
Lesson 2.2
DNA Replication and Protein Synthesis
Contents
Introduction 1
Learning Objectives 2
Warm Up 3
Learn about It! 4
The Replication of DNA 5
The Semiconservative Nature of DNA Replication 5
The General Mechanism of Replication 8
The Origin of Replication 9
Initiation of Replication 10
The Action of Polymerase during Elongation 12
Termination of Replication 14
DNA Proofreading and Repair 15
Eukaryotic Replication 15
The Central Dogma of Molecular Biology 16
Types of RNAs 17
The General Mechanism of Transcription 18
Initiation of Transcription 19
Elongation in Transcription 21
Termination of Transcription 22
Post-transcriptional Modifications 22
Overview of Translation and the Genetic Code 23
The Players during Translation 25
Mechanism of Translation 26
Post-translational Modifications 28
Key Points 29
Check Your Understanding 32
Challenge Yourself 34
Bibliography 34
,
,Unit 2: Molecular Biology and Genetic Engineering
Lesson 2.2
DNA Replication and Protein
Synthesis
Introduction
Have you had any form of bacterial or viral infection? Did you seek your doctor for a
consultation? In many cases, conditions can get better even without medications. However,
for more serious cases such as in herpes and HIV infection, further proliferation of the viruses
must be controlled. The mechanism of action of antivirals targets one crucial aspect of life—
reproduction. Reproduction entails various modes that allow the genetic material to be
transmitted from parents to offspring or progenitors. For cellular entities, reproduction
begins with the division of a cell. For a cell to divide, part of its preparation is
2.2. DNA Replication and Protein Synthesis 1
, Unit 2: Molecular Biology and Genetic Engineering
the creation of copies of its genetic material to ensure that all successive generations of cells
will have a complete set of genetic information. This is when antivirals come into action—
they prevent the synthesis of the genetic material. For example, acyclovir, a type of antiviral
drug against herpes simplex virus, targets the molecular machinery that creates copies of
DNA. This then prevents further proliferation and spread of the virus in the affected
individual.
The genetic information in cells is highly conserved and protected. Just as bacteria and
viruses perform an efficient way of creating copies of their genetic information to reproduce,
so are the cells of more complex organisms. In addition to the importance of DNA duplication,
the information must also be expressed as the traits of organisms required for maintenance
and survival. Similar to the file conversion we usually perform in our computers, the
information in DNA must be copied in an alternate version first before finally producing the
functional products. It is not used directly when synthesizing polypeptides. In this chapter,
we will look at the intricate molecular machinery that performs the replication and expression
of genetic information.
Learning Objectives Competency
In this lesson, you should be able to do the
Diagram the steps in DNA
following: replication and protein synthesis
● Explain the process of DNA replication. (STEM_BIO11/12-IIIa-b-5).
● Explain the processes involved in
transcription and translation.
2.2. DNA Replication and Protein Synthesis 2
