Viruses, Bacteria, Protists, & Fungi Microorganisms Viruses, Bacteria, Protists, & Fungi Euglenoid HIV E. Coli Fungi

The 6 Kingdoms of Life (and Viruses) Remember… Prokaryotes don’t have a nucleus (bacteria) Eukaryotes do have a nucleus (protists, fungi, plants, animals) Autotrophs make their own food using sunlight Heterotrophs must consume food

Viruses Virus- a tiny, NONLIVING particle that invades and then multiplies inside a living cell. The only way viruses are like organisms is that they can multiply. Host- living thing that provides a source of energy for an organism. Parasite- lives in a host and cause harm.

What is a Virus? - Viruses A virus is a tiny nonliving particle that enters and then reproduces inside a living cell. Virus particles are tiny compared to bacteria.

Bacteriophages Bacteriophage- a virus that infects bacteria.

The Structure of Viruses All viruses have two basic parts: a protein coat that protects the virus and an inner core made of genetic material. Some viruses are surrounded by an outer membrane envelope.

Role of Surface Proteins Each virus has unique surface proteins The shape of the surface proteins allows the virus to attach to certain cells inside the host. Virus fits to host cells like a lock- and-key. Viruses are specific to hosts AND to individual cell-types.

Rabies- brain Cold & flu virus– respiratory system Hepatitis-liver Chicken pox--skin HIV- immune cells

How Viruses Multiply Once inside a cell, a virus’s genetic material takes over many of the cell’s functions. It instructs the cell to produce the virus’s proteins and genetic material. These proteins and genetic materials then assemble into new viruses.

How Viruses Multiply - Viruses 1. Active viruses enter cells and immediately begin to multiply, leading to the quick death of the invaded cells.

How Viruses Multiply - Viruses Hidden viruses “hide” for a while inside host cells before becoming active.

Viruses and Disease Viral diseases can be spread by contact, animal bites, air, and fluids. Viral infections cannot be cured. You should rest, drink fluids, and eat well to recover. Vaccines can help prevent viral infections.

Bacteria Bacteria are much larger than viruses! Anton von Leeuwenhoek discovered bacteria with the invention of his microscope (1600s). Average size is 0.5 to 1 micrometer in diameter (one millionth of a meter!). Come in 3 shapes: spherical, rod-like, and spiral.

Bacterial Shapes Spherical- Streptococcus Rod-shaped- Bacillus Spiral- Spirillum

The Bacterial Cell - Bacteria Bacteria are prokaryotes. The genetic material in the cells is not contained in a nucleus.

Obtaining Food and Energy Some are autotrophs Make food using sunlight or chemicals. Some are heterotrophs Respiration Aerobic- requires oxygen (like us!) Anaerobic- does not require oxygen

Reproduction With the right amount of food and temperature, bacteria reproduce very quickly. Asexual Reproduction- only one parent produces offspring that are genetically identical to the parent. Binary Fission- type of asexual repro. where one cell divides to produce two identical cells.

Reproduction Sexual Reproduction- two parents combine their genetic material to produce a new organism that is different from both parents. Conjugation- type of sexual repro. where one bacterium transfers genetic material to another using a temporary bridge. Conjugation does not increase the number of bacteria, but it makes them genetically different.

Endospore Formation Endospore- small, round, thick-walled, resting cell that forms inside a bacterial cell. Contains the cells genetic material and some of its cytoplasm. Can survive freezing and boiling Endospores are light, so they can be blown by the wind. Reproduction Video

Role in Nature Most bacteria are helpful, not harmful 1. Oxygen production- autotrophic bacteria release oxygen. 2. Food production- found in dairy and other products. 3. Environmental recycling- heterotrophic bacteria decompose dead organic matter. Remember nitrogen fixers! 4. Environmental Cleanup- used to clean out water and oil spills. 5. Medicines and Health- aid in digestion

Protists Protists- eukaryotes that cannot be classified into any other kingdom. “Junk drawer kingdom” All protists are eukaryotes and live in moist places. Can be uni/multicellular, auto/heterotrophs, im/mobile

Animal-Like Protists Animal-like protists are all heterotrophs and most can move around. Protozoans- single-celled animal-like protists.

Types of Protozoans Protozoans with Pseudopods Pseudopods- temporary bulges of the cell that allow it to move. Pseudopods form when cytoplasm moves to one side of the cell. The membrane is flexible. Used to trap food Example- Amoeba

Animal-Like Protists - Protists Amoebas are sarcodines that live in either water or soil. They feed on bacteria and smaller protists.

Types of Protozoans Protozoans with Cilia Cilia- hair-like projections that move in a wave motion Cilia are used to move and get food Example: paramecium

Animal-Like Protists Paramecia are ciliates that live mostly in fresh water. Like amoebas, paramecia feed on bacteria and smaller protists.

Types of Protozoans Protozoans with Flagella Flagella- long, whip-like appendages that are used for movement. Some are helpful (live in the intestines of termites and help digest wood) Some are harmful (Giardia live in water and are intestinal parasites)

Types of Protozoans Protozoans that are parasites Diverse group, but all are parasites. Often have more than one host Example: Plasmodium (causes malaria)

Plant-Like Protists Plant-like protists are all autotrophs and most use the sun to do photosynthesis Algae- common name for plant-like protists. Important oxygen producers.

Algae Dinoflagellates

Plantlike Protists The euglena is a common protist that lives in fresh water. In sunlight, many euglenas can make their own food. Without sunlight, they obtain food from their environment. (In the dark, they eat.)

Fungus-Like Protists Fungus-like protists are all heterotrophs and use spores to reproduce. Spore- tiny cell that is able to grow into a new organism.

Fungi Fungi- eukaryotes, have cell walls, heterotrophs (absorb food), use spores to reproduce. Grow in moist places Hyphae- branching, threadlike tubes that make up the bodies of fungi. Determine the shape of the fungus.

What Are Fungi? - Fungi Fungi absorb food through hyphae that grow into the ground or food source.

Fungi Reproduction Usually reproduce by making spores Lightweight spores are carried around by wind or water. Fruiting bodies- fungal structures that produce spores. Can use asexual (budding) or sexual (hyphae grow together) reproduction.

Fungi Classification Club Fungi, Sac Fungi, and Zygote Fungi

Role of Fungi in Nature Food- yeast, mushrooms, cheeses, meats Environmental Recycling- decomposers Disease-Fighting Fungi- Penicillium Disease-Causing Fungi- athlete’s foot, ringworm, crop diseases Fungus-Plant Root Associations- attach to plants and extend their roots, which helps them grow Lichens- fungus + algae or bacteria