Viruses

What is a virus?

• Virus-A small nonliving particle that invades and reproduces inside a living cell

• Why are they nonliving again?

– Not made of cells

– Do not use energy to grow or respond to surroundings

– Cannot make food or produce waste

What are they? Cont…

• Viruses act like parasites

– Something taking advantage of another organism

• Host

– The organism being taken advantage of

• Viruses infect members of all 6 kingdoms

• Normally target a particular cell type

– Example: Cold-Cells of throat and nose

Naming Viruses

• Viruses are not alive

– No two-part name

• Virus animalis-Doesn’t exist

• Instead viruses are named after:

– The disease they cause-Polio

– Discoverers of the disease- Winter-Fittante Virus

– Location disease originated from -Ebola

What do they look like?

• Bacteriophage-bacteria eater

What do they look like? Cont…

• All shapes and sizes

– Brick shaped

– Bullet shaped

– Round

– Etc.

Structure

• Two parts

• Outer Coat-Protein coat

– Protection

– Attaching to host

• Inner Coat-Contains genetic material

– Information for making new viruses

Two Types of Viruses

• Active and Hidden

– Once a virus finds a cell they can attach to they lock on

– Invasion depends on type of virus

– Eventually, both types take over cellular machinery and use it to make copies of themselves

Type 1: Active Viruses

• Active

– Invasion

– Virus immediately begins to make new copies

– Cell bursts and virus invasion spreads

Type Two: Hidden Viruses

• Hidden (Cold Sores virus)

– Invasion

– Virus becomes part of the cell (Dormant)

– Can remain like this for a long time

– Assumes active state (see above)

• Dormant stage is believed to be ended by strong sunlight and/or stress (Cold sore virus)

Viruses in the Living World

• Ebola, Flu, AIDS, rabies

• Plant viruses deprive us of food

• But are they all bad?

– Not all

• We use some for gene therapy.

• Gene therapy-Modifying a disease on a genetic level

• Use virus to modify cell DNA

Gene Therapy Controversy

• Used to help restore normal cell function with a “good” invasion of viruses

• Example: Cystic Fibrosis-Patients don’t have genetic information for normal lung function

• However, we are modifying genetics of a person.

• God created us just as we are…are we playing god?

Gene Therapy Paper

• Write a one page, typed, persuasive paper that provides reasoning to answer the following:

• Is using gene therapy to cure diseases tampering with God’s creations?