Chapter 10 - Molecular Biology of the Gene Outline

Chapter 10 – Molecular Biology of the Gene

The structure of the Genetic Material


1 Viruses – basically packaged nucleic acid particles

1 Living or Non-living

1 genetic material is nucleic acid,

1 not cellular

2 does not reproduce on its own.

2 Nucleic acid wrapped in a protein coat (capsid) and

3 capsid and nucleic acid is sometimes surrounded by a membranous envelope (phospholipids + membrane proteins)

4 They are tiny (largest are 200nm – 1/100th of a human cell) and

1 do not carry the tools they need to reproduce

2 they need the cell’s tools!

2 Brief life cycle of Herpevirus (similar to other viruses)

1 Viruses Gain access to specific cells (nerve cells in this case)

1 trick it - proteins on virus (the ligand) fit into and bind with natural cell receptors – structure function.

2 cell takes up virus, unknowingly

2 viral DNA enters the nucleus

3 It can remain dormant until the time is right

4 Then hijack the cell and use the cellular machinery for its own purpose (to reproduce of course…).

5 Cell fills with virus particles and lyses, releasing the particles to infect other cells (the sores).

3 Once infected, it remains permanently latent, integrated into the nerve cell’s DNA.

4 75% Americans carry HSV-1 and 20% have HSV-2

5 many infected people never show symptoms

6 ability to remain latent is somewhat unusual, a trait shared with HIV

7 Viruses are far simpler on the molecular level compared to Mendel’s peas and Morgan’s flies

1 because of this, virus gave us our first glimpse of how DNA controls heredity – molecular biology

2 The chromosomal theory of inheritance set the stage for the development of a molecular understanding of the gene

3 Remember, we still don’t know what   molecule(s) is responsible for heredity. We know it has to do with chromosomes, and we know it is made of protein and DNA. So which is it? Scientists...