2Bacteria and ArchaeaMembers of the domain Bacteria live in soil, water and other organisms.The domain Archaea includes organisms that area found in extreme environments, such as hot springs.These two domains are the oldest forms of life on Earth.
3Characteristics of Bacteria There are more bacteria on Earth than there are all other living things combined.Most bacteria are too small to be seen without a microscope.Bacterium are many sizes. The largest bacteria are 1000 times as large as the average Bacterium.
4Shape of BacteriaBacteria are usually one of four main shapes, rod shaped, spherical, spiral shaped or thread-like.
5The Shape of BacteriaMost bacteria have a rigid cell wall that gives them their shape.
10FlagellaSome bacteria have hair-like parts called flagella that helps them move around. Flagella spin to push a bacterium through water or other liquids.
11ProkaryoteAn organism that does not have a nucleus is a prokaryote. Prokaryotes are single-celled organisms that do not have a nucleus.
12ProkaryotesProkaryotes function as independent organisms but they may stick together to form strand or films. Prokaryotes are much simpler and smaller than eukaryotes. They also reproduce differently.
14Binary FissionBinary fission is reproduction in which one single-celled organism splits into two single-celled organisms.Prokaryotes have no nucleus so their DNA is not surrounded by a membrane.
151st Step The DNA of prokaryotes is in circular loops 1st Step The DNA of prokaryotes is in circular loops. In the first step of binary fission, the cell’s DNA is copied.
162nd Step The DNA and its copy then bind to different places on the inside of the cell membrane.
173rd Step As the cell and its membrane grows bigger, the loops of DNA separate
184th Step When the cell is double its original size, the membrane pinches inward and a new cell wall forms and separates into two new cells, each an exact copy of the parent cell.
19EndosporesMost species of bacteria do well in warm, moist places. In dry or cold surroundings, some species of bacteria will die. In these conditions, other bacteria become inactive and form endospores.
20EndosporeAn endospore contains genetic material and proteins and is covered by a thick, protective coat. Many endospores can survive in hot, cold and very dry places.
21EndosporeWhen conditions improve, the endospores break open and the bacteria becomes active again.
22The Domain BacteriaMost known prokaryotes are bacteria. The Domain Bacteria has more individual organisms than all other domains combined do. Bacteria have lived on the earth for more than 3.5 billion years.
23Classification of Bacteria Bacteria are classified in part by the way they get their food.Most bacteria are consumers. They eat other organisms like leaves.Some bacteria are decomposers which feed on dead organisms.Other bacterial consumers live in or on the body of another organism.Bacteria that make their own food using energy from sunlight are producers.
24Cyanobacteria are producers that usually live in water.
25Cyanobacteria Cyanobacteria contain the green pigment chlorophyll. Chlorophyll is important to photosynthesis, the process of making food from the energy in sunlight.
26Cyanobacteria Some have a blue pigment. Some have a red pigment. Flamingos get their pink color from eating red cyanobacteria.
27The Domain Archaea The three main types of archaea are: heat lovers salt loversmethane makers.
28Heat Lovers Heat lovers live in ocean vents and hot springs. They live in very hot water, usually from 60° to 80°C, but they can survive temperatures of more than 250°C.
29Salt LoversSalt lovers live in environments that have high levels of slat such as the Dead Sea or the Great Salt Lake.
30Methane MakersMethane makers give off methane gas and live in swamps and animal intestines.
31Harsh Environments Archaea live where nothing else can. Most archaea prefer environments where there is little or no oxygen.They have been found beneath 430 m of ice in Antarctica.
32Good for the Environment Bacteria are good for the environment. Bacteria is a part of:Nitrogen fixationRecyclingCleaning up
33Recycling Dead Matter Life could not exist without bacteria since they recycle dead matter..
34Nitrogen Fixation Plants need nitrogen to grow. Nitrogen makes up 78% of the air.Nitrogen fixing bacteria take oxygen from the air and change it into a form that plants can use.
35Cleaning UpBacteria and other microorganisms are also used to fight pollution.Bioremediation means using microorganisms to change harmful chemicals into harmless ones.
36Good for People Bacteria is also good for people in many ways. Bacteria in foodMaking MedicinesInsulinGenetic Engineering
37Bacteria in your FoodYogurt, buttermilk and sour cream are all made with bacteria.Lactic-acid producing bacteria break down the sugar in milk, which is called lactose, and change it into lactic acid.
38Making MedicineAntibiotics are medicines used to kill bacteria and other microorganisms.Many antibiotics are made by bacteria.
39InsulinThe human body needs insulin to break down and use sugar and carbohydrates.People who have diabetes do not make enough insulin.Scientists put genes into bacteria so they will make insulin.
40Genetic EngineeringWhen scientists change the genes of any living thing it is called genetic engineering.In 1973 they put genes from a frog into bacteria that then began to make copes of the frog genes.
41Harmful BacteriaPathogenic bacteria cause disease by getting inside a host organism and taking nutrients from the host’s cell and harming the host.People cam get vaccines to protect against disease.
42Diseases in other Organisms Pathogenic bacteria attack plants, animals, protists, fungi and other bacteria.Scientists have genetically engineering plants to be resistant to disease causing bacteria.
43VirusesA virus is a microscopic particle that gets inside a cell and often destroys the cell.Many viruses cause diseases, such as the common cold, flu and AIDS.
44Viruses Viruses are smaller than the smallest bacteria. About 5 billion virus particles could fit in a single drop of blood.Viruses can change rapidly. This makes them hard to fight.
45Are Viruses Living? Viruses contain protein and genetic material. They can’t eat, grow, break down food or use oxygen.They cannot function on their own.It can only reproduce inside a living cell that serves as a host.A host is a living thing that a virus or parasite live on or in.The virus forces the host to make viruses rather than healthy new cells.
46Classifying Viruses Viruses are classified by Their shape The type of disease they causeThe kind of genetic material they contain.
47Crystal shaped viruses like the Polio Virus cause disease.
48Sphere shaped VirusesInfluenza viruses look like spheres. HIV is another virus that has this structure
49Cylinder shaped Viruses The tobacco mosaic virus is shaped like a cylinder and attacks tobacco plants.
50Spacecraft One group of viruses attacks only bacteria. Many of these look like spacecraft.
51VirusEvery virus is made up of genetic material inside a protein coat.The protein coat protects the virus and helps it to enter a host cell.
52Genetic Material in Viruses The genetic material in a virus is either RNA or DNA.Most RNA is made of one strand of nucelotides.Most DNA is made up of two strands of nucleotides.
53Viruses and SicknessThe viruses that cause warts and chicken pox contain DNA.The viruses that cause colds and the flu contain RNA.The virus that causes AIDS contains RNA.
54The Lytic CycleThe viruses attack living cells and make more of themselves.This cycle is called the Lytic Cycle.
55The Lysogenic CycleSome viruses don’t go straight into the lytic cycle.These viruses put their genetic material into the host but remains inactive.When a virus is in a resting phase this known as the lysogenic cycle.
56Treating a Virus Antibiotics do not kill viruses. Scietitst have developed antiviral medicines which stop viruses from reproducing.Vaccinations keep you from getting a viral infection, such as chickenpox.