Structure and Functions of MicroorganismsClassification of Life - Prokaryotes vs. Eukaryotes - Bacteria, Parasites, Fungi & Viruses

Classification of Life

ThinkWell Video

What’s the main difference between prokaryotic and eukaryotic cells?

• Organisms without a cell nucleus or any other membrane bound organelle

• DNA found in the nucleoid within the cytoplasm of organism.

• Examples: Bacteria and Archaea.

• Organisms whose cells are organized into complex structures organelles.

• DNA found in the nucleus.

• Examples: Plants, Animals, Fungus, and Protist

Prokaryotes Eukaryotes

Prokaryotes vs. Eukaryotes

Prokaryotes vs. Eukaryotes

Prokaryotes - BacteriaEukaryotes - Animal

Review of Prokaryotes vs. Eukaryotes & Classification of Life.

• Brain Pop- Cell Specialization, Six Kingdoms

BACTERIA

Bacteria – Quick Facts

• Size – Single Cell (1-2 micrometers)

• Shape – Spiral, Rod-like, Corkscrew, Spherical

• Structure – Prokaryotic Cell (No Nucleus)

• Food – By absorbing nutrients from the material they live on or in. (Heterotrophs)

• Movement – Flagella and Pili.

Bacteria - Introduction

• Bacteria can live in a variety of places (with oxygen, without oxygen, extreme hot, extreme cold). Extreme Bacteria = Archaea.

Bacteria - Reproduction

• Bacteria reproduce through binary fission.

• Under optimal conditions, bacteria can grow and divide extremely rapidly, and bacterial populations can double very quickly.

Bacteria - Diseases

• Millions of bacteria live on the skin and in the intestines.

• The vast majority of bacteria do not cause disease, and many bacteria are actually helpful and even necessary for good health.

• Harmful bacteria that cause bacterial infections and disease are called pathogenic bacteria.

• Bacterial diseases occur when pathogenic bacteria get into the body and begin to reproduce and crowd out healthy bacteria.

Bacteria - Diseases

Examples:

• Escherichia coli (E. coli) and Salmonella cause food poisoning.

• Streptococcal bacteria cause a variety of infections in the body, including pneumonia, meningitis, ear infections, and strep throat.

Salmonella E. coliStreptococcal bacteria

Bacteria – Shape/TypeSpherical, Rod-like, Spiral, Corkscrew

• Spherical – Known as cocci.

• Strep Throat

• Rod-like – Known as bacilli

• Salmonella

• Spiral – Known as spirilla

• Oceanospirllum

• Corkscrew – Known as helical

• Lyme Disease - Borellia

Bacteria - Treatment

• Antibiotics are used to inhibit the growth of bacteria.

• Biotics—of or having to do with life or living organisms

• Because antibiotics have been overused, many diseases that were once easy to treat are becoming more difficult to treat.

• Antibiotic resistance in bacteria occurs when mutant bacteria survive an antibiotic treatment and give rise to a resistant population.

Bacteria Wrap Up

• Brain Pop – Bacteria, Antibiotic Resistance

PARASITES

Parasites – Quick Facts

• Size – 70% of all parasites that can live in the human body are MICROSCOPIC - only 30% are visible to the naked eye.

• Shape – bacterial, fungal, protist, macro organisms

• Structure – specialized anatomically and physiologically to exploit host

• Food – live on or in a host’s body

• Movement – food, water, blood, vectors

Parasite – How does it live and grow?

• Natural selection favors adaptations that allow a parasite to efficiently exploit its host.

• Tapeworms are so specialized for a parasitic lifestyle that they do not even have a digestive system.• They live in the small intestine of their host and

absorb nutrients directly through their skin.

Parasites - Disease

• Infectious disease may also be caused by animal parasites, which may take up residence in the intestines, bloodstream, or tissues.

Lyme Disease

Male Tick

Malaria

FUNGI

Fungi – Quick Facts

• Size – 2-10 um, 20-25 cm

• Shape – cell walls with chitin

• Structure – hyphae with spores attached

• Food – heterotrophic

• Movement – spores in the air

Fungi

• Fungi are eukaryotic, non-photosynthetic organisms, and most are multicellular heterotrophs.

Mushrooms Truffle Lichen

Fungi - Reproduction

• Sexually (similar to plants) and Asexually (producing spores).

• When the environment is favorable, asexual reproduction ensures an increased spread of the species.

Fungi - Diseases

• Fungi can sometimes attack the tissues of living plants and animals and cause disease.

• Fungal disease is a major concern for humans because fungi attack not only us but also our food sources, making fungi competitors with humans for nutrients.

Athlete’s Foot

Blight Fungus

Fungi - Diseases

• Mold spores can cause mild to serious allergies in some people. Billions of mold spores can become airborne and may then be inhaled, triggering an allergic reaction.

Mold Spores

Mold Spores

Fungi - Treatment

• Athlete's foot is treated with topical antifungal medication (a drug placed directly on the skin) in most cases. Severe cases may require oral drugs (those taken by mouth). The feet must be kept clean and dry since the fungus thrives in moist environments.

Fungi - Activities

• Brain Pop

VIRUS

Virus – Quick Facts

• Size – 0.03-.003 micrometers (um)

• Shape – helical, polyhedral, enveloped

• Structure –protein coat with DNA or RNA

• Food – host cell ???????

• Movement – vectors, blood, air, contact, water, food

Virus

• Viruses are non-living particles composed of a nucleic acid (DNA or RNA) and a protein coat.

• Are much smaller than bacteria

Virus - Structure

• The term virus comes from the Latin word that means “poison”.• Consist of genetic material contained inside a protective protein called a capsid.

Virus - Reproduction

• Viruses need a host cell to reproduce.

• Viruses are not living.

Harmful Viruses

• Viral illnesses range from mild fevers to some forms of cancer and include several other severe and fatal diseases.

• Polio, Smallpox, diphtheria, HIV, influenza, Ebola, West Nile, mononucleosis, measles/mumps

Polio

Mononucleosis

Harmful Viruses

HIV Ebola

Viral Transmission

• Viral diseases are among the most widespread illnesses in humans.

• Transmission of these illnesses varies; some are transmitted by human contact, while others are transmitted through water or an insect bite.

• Sometimes the host cell is killed sometimes it is not.

• Sometimes a virus is harmful sometimes it is not.

Virus – Treatment/Prevention

• When you get a virus your body fights it off and builds immunities against it in the form of antibodies.

• Vaccines and some anti-viral drugs are used to control and prevent the spread of viral diseases.

Why are viruses not listed on here?

Vector

• Mechanisms or organisms (excluding humans) that spread diseases without showing symptoms.

• Latin word meaning “carrier”.

Disease

• a disease outbreak happens when a disease occurs in greater numbers than expected in a community or region, or during a season.

• An outbreak may occur in one community or even extend to several countries.

• It can last from days to years.

• Sometimes a single case of a contagious disease is considered an outbreak.