Daily Science Which has more bacteria, a toilet or a gym? Answer: a gym has 1,000 times more When sweat combines with feet or a yoga mat at a gym why can this cause problems? Answer: sweat reactivates the bacteria and brings past bacteria/viruses back to “life” If a gym owner does a good job of cleaning their equipment every day, how can this lead to antibiotic resistance? Answer: the bacteria left behind reproduce and pass on their “superbug” resistant DNA Name a few ways you saw in the video that bacteria can travel from one place to another. Answer: Sneezing, coughing, yoga mat, flies, dogs

Daily Science-Bacteria Review Pick the correct answer about bacteria cells from the following… They are large or small? They are simple or complex? They are prokaryotic or eukaryotic? They have a nucleus yes or no? Hint: get out your Requirements of Life Notes! small simple prokaryotic no

Remember they are a single celled organism!

Viruses Biology I

What is a Virus? Viruses are not alive. Viruses are particles of nucleic acid, protein, and sometimes lipids. A typical virus is composed of a core of DNA or RNA surrounded by a protein coat. Simplest viruses have only a few genes, whereas the most complex have hundreds to thousands. The protein coat is called the “capsid.”

Virus Structures Bacteriophage Tobacco Mosaic Virus Influenza Virus

Tricking Their Way In Proteins on the capsid bind to the surface of the cell and “trick” the cell into letting the virus in. Because viruses have to bind to the surface of the cell, they are highly specific. Plant viruses only infect plant cells, animal cells only infect certain types of animals, etc. Some viruses infect bacteria (bacteriophages).

Viral Infections Once a virus enters the cell, there are two different processes that can occur.

Viral Infection – Lytic Infection Virus enters the cell. Virus makes copies of itself inside the cell. The cell fills with viruses and bursts open (lyses).

Viral Infection – Lysogenic Infection Virus enters the cell. Virus integrates itself into the DNA of the host cell. Viral information is made indefinitely by the cell during the cell’s normal processes. Eventually, the virus will leave the host cell and enter the lytic infection cycle.

What are diseases caused by lysogenic viruses? Think about it…they are things that lie dormant in the human body and come back to make you sick later in life Shingles (from chickenpox when you are younger) Warts (can come back repeatedly)

Check out this video on how the ebola virus takes over a cell’s machinery

Retroviruses Retrovirus - a virus that only contains RNA. Retroviruses infect a cell and use the cell to produce a DNA copy of their RNA. Responsible for some types of cancer and for AIDS.

Viruses & Living Cells Viruses must infect a living cell in order to grow and reproduce. Viruses have to use the host’s respiration, nutrition, and all other functions. Viruses are parasites – they depend completely on the host for their existence and harm the host in the process. Viruses continue to evolve and do so quickly!

Types of Viruses Cold (lytic) Flu (lytic) HPV (warts, lyso) HIV (lyso) Smallpox Polio Herpes (lyso) Hepatitis (lyso) Measles Mumps Rabies (lytic) West Nile Ebola (lyso)

Venn Diagram Bacteria and Viruses- Partner up! Turn to page 9 in IAN’s Same Viruses

Know Want to Know Learned