Bacteria

Bacteria Characteristics *Prokaryote – no nucleus *Living *Decomposer

IDENTIFICATION Shape *Rod shaped (Bacilli) *Round shaped (cocci) *Spiral shaped (spirilla) Movement- *flagella *spiral *no movement

How do bacteria replicate? *Binary Fisson-By dividing in half – similar to how our cells divide.

How do bacteria cause diseases? 1.Damage the tissue of the infected organism by directly breaking them down for food *Tuberculosis – break down lung tissue

Video clip *Food poisoning – meat or eggs 2. Release poisons that harm the body *Food poisoning – meat or eggs *Streptococcus – step throat or scarlet fever (reddish rash all over the body) Video clip

Copyright Pearson Prentice Hall Arrangement Paired: diplo Grape-like clusters: staphylo Chains: strepto Copyright Pearson Prentice Hall

GENETIC RECOMBINATION -Many bacteria can take in foreign DNA -Increased diversity/antibiotic resistance: 1. Transformation 2. Conjugation 3. Transduction Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall CONJUGATION FRONT OF FLASH CARD BACK OF FLASH CARD -hollow bridge/tube to exchange DNA - increases genetic diversity Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Environmental DNA Transformation Front of flash card Back of flash card prokaryote take in DNA from its environment. Copyright Pearson Prentice Hall

Transduction (FRONT OF CARD) BACK OF CARD -virus gets small part of host cell/prokaryote DNA. -virus copies itself in host -carries prokaryote DNA to next cell Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Bacterial Metabolism Bacteria are living. Require a constant supply of energy and materials to grow/live. Photo-heterotroph: Chemo-heterotroph: Photo-autotroph: Chemo-autotroph: CO2 CO2 Copyright Pearson Prentice Hall

Producers or consumers??? Bacteria need energy AND carbon to live. Heterotrophs: photoheterotroph-light energy, carbon from organisms. chemoheterotroph- BOTH energy/carbon from other organisms Autotrophs photoautotrophs-light energy, carbon from CO2. chemoautotroph-energy from inorganic compounds, carbon from CO2 Copyright Pearson Prentice Hall

If a bacteria is feeding on a dead tortoise in the sunshine in the desert, which type bacteria/metabolism would it be? Photoheterotroph What if a bacteria was feeding on a dead animal all day and all night regardless if there was sunlight or not? chemoheterotroph

Antibiotic Resistant Bacteria Natural selection: Resistant bacteria survive/reproduce Those not resistant die. Some bacteria mutate or pick up plasmid DNA that allows them to be “immune” to antibiotics Whole population becomes resistant Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall http://www.youtube.com/watch?v=AYvX8tnCM9s Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall

Can you get rid of a bacterial infection? *Yes ! *Antibiotics –block growth and reproduction of bacteria penicillin and tetracycline

Are there good bacteria? Used to produce: cheese, yogurt, buttermilk and sour-cream, pickles, wine Video Clip

Viruses Video Clip

READ ONLY What makes something a living organism? In isolation, viruses and bacteriophages show none of the expected signs of life. They do not respond to stimuli, they do not grow, they do not do any of the things we normally associate with life.

Viruses Non-living particle made of: -nucleic acid (DNA or RNA) -a protein coat

Viruses Characteristics: NOT living Can only reproduce inside a living cell No cellular functions /cytoplasm Don’t grow/move on their own Don’t need energy/food Don’t respond to stimuli

Virus Anatomy DNA or RNA Protein Coat (called a CAPSID) Sometimes have lipids

Bacteriophage Virus that infects ONLY bacteria

Common Viral Infections Polio HIV Flu Cold Fever

Retrovirus A retrovirus’ genetic information is copied backward— from RNA to DNA. This DNA is inserted into the host cell DNA The virus that causes AIDS is a retrovirus.

HIV is a retrovirus injecting the enzyme, reverse transcriptase into the cell to copy viral RNA into DNA.

Viruses are host specific – a protein on the surface of the virus has a shape that matches a molecule in the plasma membrane of its host, allowing the virus to lock onto the host cell.

HIV is a retrovirus injecting the enzyme, reverse transcriptase into the cell to copy viral RNA into DNA.

Viruses are host specific – a protein on the surface of the virus has a shape that matches a molecule in the plasma membrane of its host, allowing the virus to lock onto the host cell.

HIV doesn’t target just any cell, it goes right for the cells that want to kill it. “Helper" T cells are HIV's primary target. These cells help direct the immune system's response to various pathogens.

HIV undermines the body's ability to protect against disease by depleting T cells thus destroying the immune system. The virus can infect 10 billion cells a day, yet only 1.8 billion can be replaced daily.

After many years of a constant battle, the body has insufficient numbers of T-Cells to mount an immune response against infections. At the point when the body is unable to fight off infections, a person is said to have the disease AIDS. It is not the virus or the disease that ultimately kills a person; it is the inability to fight off something as minor as the common cold.

Virus Reproduction http://www.youtube.com/watch?v=Rpj0emEGShQ&feature=related

Viral Vector A carrier of the virus(from one host to another) If infected bird is bitten by a mosquito, then the mosquito bites and infects a human… Which is the vector? The bird, mosquito, or human? ANSWER-the mosquito Create your own team example EX: humans, animals, ticks, fleas, mosquitos

Viral Infection Lytic Infection – 1.virus enters the cell 2. copies itself 3. causes the cell to burst

Lytic Infection Animation http://sites.fas.harvard.edu/~biotext/animations/lyticcycle.html

Viral Infection Lysogenic Infection – 1. virus enters the cell 2. Hides/remains dormant 3. then enters lytic cycle

The Lysogenic Cycle

Can you get rid of a viral infection? No – never(if it’s latent) The virus will remain in your body permanently. It will be dormant until activated again. Symptoms can be helped but there is no cure.

Pathogen Any disease causing agent Virus Bacteria Parasites Molds, fungus

Treating diseases Antibiotic-Block growth and reproduction of bacteria. Used after you are infected Does NOT work on a virus! BACTERIA ONLY! Ex: Penicillin, Erythromycin, Amoxicillin Vaccine-Preparation of killed or weakened pathogens When injected prompts body’s immune response Only effective BEFORE you get the disease Virus OR bacteria

Can you prevent a viral infection? Yes – vaccination if done before the infection begins Video Clip