GRAM Negative The Structure of Bacteria Cell Membrane Pilli EuKaryote Salmonella T.DEjulio2010 Plasmid Ribosome Flagellum Capsule Nucleoid Cell Wall

Bacteria Our invisible friends / Pro – before---Karyon – nucleus Bacteria derived from the Greek word bacterion meaning "small staff”. Earth’s first cells were prokaryotes. The simplest forms of life are prokaryotes. Foes

Lots of Them! Prokaryotes are earth’s most abundant life forms. They can survive in many environments. They can get energy from many different sources.

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Scientists classify living organisms into DOMAINS New technology- DNA comparison Add a classification above kingdoms called Domains

There are 3 Domains: Eukarya, Archaea, Bacteria

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Archaea and Bacteria are prokaryotes and have prokaryotic cells “karyote” = kernel “pro” = before Prokaryotes are older than eukaryotes, simpler, smaller, and do NOT have a true nucleus Prokaryotic Cell

Archaea found in 1970 by Dr. Carl Woese Survive in extreme environments – called extremophiles Hot springs, deep sea vents Extremely acid environments Extremely alkaline environments Extreme salty environments = thermophiles = acidophiles = alkaliphile = halophiles

1. What are the 3 different domains named? 2. What domain or domains contain eukaryotic cells? 3. What domain or domains contain prokaryotic cells? 4. What is special about archaea? Check Point

Bacteria Structure

Bacillus = Rod Shape

Cocci = Sphere Shape

Spirochete = Spiral Shape

Flagellum for Movement

Pilli for Attaching/Reproduction

Capsule for Protection Capsule made of polysaccharides SUGARS!

Cell Wall for Structure Cell wall is outside the cell membrane, but inside the capsule Made of peptidoglycan

Cell Wall for Structure 2 types of bacteria based on different cell walls: –1. Gram Positive Bacteria THICK peptidoglycan Stains purple –2. Gram Negative Bacteria THIN peptidoglycan Has outer membrane Stains pink

Cell Wall for Structure 2 types of bacteria based on different cell walls: –1. Gram Positive Bacteria THICK peptidoglycan Stains purple –2. Gram Negative Bacteria THIN peptidoglycan Has outer membrane Stains pink

Cytoplasm contains proteins, fats, carbohydrates, and other materials

Ribosomes float in cytoplasm and make proteins

Nucleic acids float in the cytoplasm in the nucleoid region of the cell as plasmids Plasmids = circular DNA or a loop of DNA

Endospores are for the protection of bacterial DNA during dormancy When bacteria cell becomes dormant, it uses an endospore to protect its DNA

Check Point 1. Draw a cocci shaped bacteria 2. Draw a bacillus shaped bacteria 3. Describe the function of: a. Flagellum b. Pilli c. Ribosomes d. Capsule e. Endospore 4. What is the cell wall made out of? 5. Explain the differences between a Gram negative and Gram positive bacterium

Bacteria Reproduction

Bacteria reproduce asexually by binary fission 1.Loops of DNA replicate DNA attaches to cell membrane Cell cytoplasm doubles 4. Cell splits in half = Cytokinesis This results in 2 genetically identical daughter cells!

Binary fission allows bacteria to grow exponentially Would you rather a have million dollars OR a penny that doubles every day for 1 month?

Some bacteria divide every 20 minutes Bacteria stop growing when environmental conditions are bad: –Not enough food/nutrients –Not enough space –Bacteria produce waste and waste pollutes environment

Bacteria reproduce sexually by conjugation Conjugation: Formation of a pili between 2 cells through which DNA is exchanged.

How do Bacteria obtain nutrients? Autotrophic bacteria can make their own food by: 1. Photosynthesis: using sunlight 2. Chemosynthesis: using chemicals from the environment.

Heterotrophic bacteria must obtain food from environment by consuming other organisms. 1. Parasitic bacteria feed off of host harming the host (disease). 2. Mutualistic bacteria feed off of host but help host to break down nutrients. 3. Decomposing bacteria feed off of dead organisms, breaking them down.

Bacteria need an energy source and a carbon source Nutritional TypeEnergy Source Carbon Source PhotoautotrophsSunlightCO 2 ChemoautotrophsInorganic chemical CO 2 PhotoheterotrophSunlightOrganic Compound ChemoheterotrophOrganic Compound

Bacteria release energy in 2 different ways How do bacteria release energy? Aerobic Cellular Respiration: using oxygen to release energy. Anaerobic Cellular Respiration: releases energy without using oxygen.

How can the rate of bacteria growth be slowed down? Refrigeration Freezing How can Bacteria be killed? Antibacterial soap/detergents Cooking Antibiotics/penicillin

Helpful Bacteria Used to treat sewage –Organic waste is consumed by the bacteria, used as nutrients by the bacteria, and is no longer present to produce odors, sludge, pollution, or unsightly mess Foods like yogurt, cottage and Swiss cheese, sour cream, buttermilk are made from bacteria that grows in milk

Homework Find 1 other reason bacteria are helpful (on a notecard or small piece of paper) Include proper heading and citation of your source

ProkaryoteArchaeaEukaryote