Viruses
What is a Virus?
•Segments of nucleic acids wrapped in a ______coat.
•They are not ______.
•Smaller than ______cells.
•Visible only with ______microscope.
•Are ______= ______causing
•Do not ______, have ______, or ______.
•They reproduce by ______cells and using the cell to make more ______.
•In Latin, virus means “______”.
Viral Structure
•Protein coat = ______
•Contains ______or ______, but not both.
•Surrounding membrane of the capsid = ______
•RNA viruses
–______, ______, ______
•DNA viruses
–______, ______, ______
•______= protein with carbohydrates and specific enzymes
Viral Structure
•Viruses come in many ______.
–Long ______(Ebola)
–______(influenza)
–______(tobacco mosaic)
–______(many sided)adenoviruses (Respiratory illnesses)
Bacteriophage
•Virus that infects ______cells
•Most common bacteriophage is the ______
Viral Reproduction
•Most viruses reproduce inside ______cells. What makes this an ideal place?
–Bacteria reproduce ______
–(every ______minutes)
•______types of reproductive life cycles are known.
1. Lytic Cycle
•Virus attaches to ______cell and injects its ______into the bacteria
•Uses the host bacteria cell to replicate the ______and ______(capsid).
•Virus ______the bacteria cell by ______the cell and releasing ______viruses.
2. Lysogenic Cycle
•Virus attaches to ______cell and injects its ______into bacterium and ______with the bacteria’s DNA
–It is now called a ______
•Host cell divides ______—along with the viral DNA (Virus remains ______inside bacteria)
•If ______of bacteria cell changes, the virus will enter the ______cycle and destroy the bacteria cell to release ______viruses
•______Blisters (cold sores)
–Virus hides deep in ______cells
–When conditions become ______(such as stress) the virus ______cells and causes tissue damage, which is a ______blister or ______sore.
Viral Diseases
•
•
•
•
•
•
•
•
•
• (severe acute respiratory syndrome)
•
•
Viral Diseases
•Some viruses cause ______
–Hepatitis B ______cancer (vaccine available)
–Epstein-Barr virus ______
–HPV (Human papilloma virus)______cancer (vaccine available)
Emerging Viruses
•______arrived at a location or a new ______virus form
•1999- ______virus arrives in US
–Came to US on an infected ______
–Mild ______-like symptoms
–Causes brain ______in elderly or infirm death
•______virus
–______US - 1993
–Found in ______droppings
–Virus is ______to 38% of its victims
Prions
•Stanley Prusiner found a new class of ______called prions.
–They contain ______but no ______acids.
–Cause diseases such as ______(brain disease in sheep), ______(brain disease), ______-______disease (human version of mad cow disease).
Viroids
•Single stranded ______with no ______coat (capsid)
•Usually affect ______plants such as cucumbers, ______, avocados, ______
Vaccines
•Vaccines prevent a person from ______a disease.
•______or ______form of the virus injected into body
•Body ______virus and builds ______against the disease.
•Antibodies ______and ______the virus immediately if it enters the body again
•______and ______have been eliminated from earth due to vaccinations
•______–polio vaccine
1