BACTERIA vs VIRUS Biology Chapter 24 1 Bacteria

BACTERIA vs VIRUS Biology Chapter 24 1

Bacteria are very small 2

This is a pore in human skin and the yellow spheres are bacteria 3

Bacteria are very small compared to cells with nuclei 4

Evolution/Classification Most numerous on Earth ¡ Most Ancient ¡ Microscopic Prokaryotes ¡ Evolution has yielded many species adapted to survive where no other organisms can. ¡ Grouped based on: ¡ l l l Structure, physiology, molec. Composition reaction to specific types of stain. Eubacteria= Germs/bacteria Archaebacteria 5

Chemosynthetic bacteria use the sulfur in the “smoke” for energy to make ATP. 6

The red color of this snow is due to a blue-green bacteria 7

Kingdom Eubacteria ¡ Can have one of three basic shapes 1. Bacilli – rod-shaped 2. Spirilla – spiral-shaped 3. Cocci – sphere-shaped Staphylococci – grape-like clusters Streptococci – in chains SHOW ME 8

Bacillus bacteria are rod or sausage shaped 9

Coccus bacteria are sphere or ball shaped 10

Spirillium bacteria have a corkscrew shape 11

Diplo-bacteria occur in pairs, such as the diplococcus bacteria that causes gonorrhea 12

Staphylo bacteria occur in clumps, such as this staphylococcus bacteria that causes common infections of cuts 13

Streptobacteria occur in chains of bacteria, such as this streptococcus bacteria that causes some types of sore throats 14

STRUCTURE OF BACTERIA Structure Function Cell Wall Protects and gives shape Outer Membrane Protects against antibodies (Gram Neg. Only) Cell Membrane Regulates movement of materials, contains enzymes important to cellular respiration Cytoplasm Contains DNA, ribosomes, essential compounds Chromosome Carries genetic information Plasmid Contains some genes obtained through recomb. Capsule & Protects the cell and assist in attaching cell to Slime Layer other surfaces Endospore Protects cell agains harsh enviornments Pilus Assists the cell in attaching to other surfaces Flagellum Moves the cell 15

No Nucleus-DNA in Cytoplasm 16

Nutrition and Growth ¡ ¡ Heterotrophic or Autotrophic Some are Photoautotrophs – Use sunlight for Energy Some are Chemoautotrophs. Many are Obligate Anaerobes. l Oxygen = Death ¡ Ex. ¡ Some are Faculatative Anaerobes l With or without Oxygen ¡ Ex. ¡ ¡ Clostridium tetani – Tetanus Escherichia Coli Some are Obligate Aerobes l Ex. ) Mycobacterium tuberculosis Temperature requirements l Some are Thermophilic, Some prefer acidic envmt. 17

Bacteria and Disease Pathogen Areas affected Mode of transmission Botulism Clostridium botulinum Nerves Improperly preserved food Cholera Vibrio cholerae Intestine Contaminated water Dental Caries Streptococcus mutans, sanguis, salivarius Teeth Environment to mouth Gonorrhea Neisseria gonorrhoeae Urethra, fallopian Sexual contact Lyme disease Berrelia burgdorferi Skin, joints Tick bite Rocky Mountain SF Rickettsia recketsii Blood, skin Tick bite Salmonella Intestine Contaminated food, water Strep throat Streptococcus pyogenes URT, blood, Sneezes, coughs, etc. skin Tetanus Costridium tetani Nerves Contaminated wounds Tuberculosis Mycobacterium tuberculosis Lung, bones coughs 18

Some bacteria cause diseases -Disease causing bacteria are call PATHOGENIC 19

Helicobacter pylori is the pathogenic bacteria that can causes ulcers 20

Leprosy is a bacterial infection that decreases blood flow to the extremities resulting in the deterioration of toes, ears, the nose and the fingers. 21

CHOLERA 22

LYME DISEASE 23

SALMONELLA 24

STREP THROAT 25

Common Antibiotics Antibiotic Mechanism Target bacteria Penicillin Inhibits cell wall synthesis Gram Positive Ampicillin Inhibits cell wall synthesis Broad spectrum Bacitracin Inhibits cell wall synthesis Gram Positive – Skin Ointment Cephalosporin Inhibits cell wall synthesis Gram Positive Tetracycline Inhibits Protein Synthesis Broad spectrum Streptomycin Inhibits Protein Synthesis Gram Neg. tuberculosis Sulfa drug Inhibits cell metabolism Bacterial meningitis, UTI Rifampin Inhibits RNA synthesis Gram Pos. , some Neg. Quinolines Inhibits DNA Synthesis UTI 26

Some Final Information ¡ ¡ Because antibiotics have been overused, many diseases that were once easy to treat are becoming more difficult to treat. Some Bacteria are Useful l Ex. ) Producing and Processing food Breaking down dead organic material Make unripened cheese like ricotta and cottage by breaking down the protein in milk. 27

VIRUSES Non-living but depends on the living! 28

STRUCTURE ¡ ¡ ¡ Nonliving Composed of Nucleic acid and protein Cause many diseases Virology – Study of Viruses Comparison of Viruses and Cells below Char. Of Life Virus Cell Growth No Yes Homeostasis No Yes Metabolism No Yes Mutation Yes Nucleic acid DNA or RNA DNA Reproduction Only within host cell Independently by cell division Structure Nucleic acid core, protein covering, some have envelope Cytoplasm, cell membrane, etc. . 29

Here is a non-enveloped bacteria virus inserting it’s DNA into a bacterial cell. 30

Characteristics of Viruses ¡ ¡ ¡ 2 essential features 1. Nucleic Acid l May be DNA or RNA l Helical, closed loop, or long strand 2. Protein Coat – called CAPSID Some have ENVELOPE l Ex. Influenza, chickepox, herpes simplex, HIV VIRAL SHAPE l Icosahedron – 20 triangular faces ¡ Ex. ) herpes, chickenpox, polio l Helix – Coiled spring ¡ EX. )Rabies, measles, tobacco mosaic 31

All viruses have two main parts: 1. DNA or RNA – genetic info 2. Capsid – a protein encasement 32

Grouping Viruses ¡ Grouped according to: l Presence of Capsid and envelope – shape l RNA or DNA, single or double stranded – struct. Viral Group Nucleic Acid Shape and Structure Example Papovaviruses DNA Icosahedral, non-env. Warts, cancer Adenoviruses DNA Icosahedral, non-env. Resp. & intestinal infections Herpesviruses DNA Icosahedral, enveloped Herpes simplex, chicken pox, mono, shingles Poxviruses DNA Complex brick, enveloped Small pox, cow pox Picornaviruses RNA Icosahedral, non-env. Polio, hepatitis, cancer Myxoviruses RNA Helical, enveloped Influenza A, B, C Rhabdoviruses RNA Helical, enveloped Rabies Retroviruses RNA Icosahedral, enveloped AIDS, cancer 33

Grouping Viruses ¡ Viroids- The smallest known particle that can replicate. l l ¡ Disrupt plant cell metabolism Can destroy entire crops Prions – Abnormal forms of proteins that clump together inside cells. l l Clumping eventually kills the cell Examples Scrapie – in sheep ¡ Mad Cow Disease ¡ 34

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Viral Replication Picture http: //www. mcgrawhill. ca/school. Graphics/biology 2_1. mpg Click Movie to Play 36

Viruses and Human Disease ¡ Control and Prevention of spread. l Vaccination & Antiviral drugs ¡ ¡ Emerging Viruses – exist in isolated habitats l ¡ Ex. ) chickenpox vaccine, AZT, Acyclovir, protease inhibitors. Do not usually infect humans unless environmental conditions favor contact. Several viruses are now linked to cancers such as leukemia, liver cancer, Burkitt’s lymphoma, cervical cancer. 37

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PAPOVAVIRUSES BACK 42

ADENOVIRUSES BACK 43

HERPESVIRUSES BACK 44

POXVIRUSES BACK 45

After polio infections, the killer T-cell have destroyed the motor neurons that are producing the virus. The result is a loss of muscle control including the diaphragm. The iron lung changes the pressure to pump air in and out of the lungs. 46

Which US President had polio? 47

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