Prokaryotes Single celled Lack a nucleus Includes only

Prokaryotes • Single celled • Lack a nucleus • Includes only Eubacteria and Archaebacteria Kingdoms

Eubacteria • Includes a wide range of bacteria • Usually surrounded by a cell wall made of peptidoglycan and a cell membrane

Archaebacteria • Live in extreme environments • Lack peptidoglycan • Contain different lipids than eubacteria • Thought to be ancestors to eukaryotes

Identifying Prokaryotes • Shapes –Bacilli-Rod shaped –Cocci- Spherical –Spirilla- Spiral

Identifying Prokaryotes • Cell walls –Gram positive- Purple stain • Cell wall contains only peptidoglycan –Gram negative- Pink stain • Cell wall contains an extra layer of carbohydrates

Identifying Prokaryotes • Movement –Flagella- Whiplike structures for movement –Lashing –Snaking –Spiral movement

Prokaryotes Obtaining Energy • Autotrophs- Make their own food – Photoautotrophs- Use sunlight to make their own food – Chemosynthesis- Using chemicals to make their own food • Heterotrophs- Consume other organisms – Photoheterotrophs- Consume other organisms and have the ability to make their own food

Releasing Energy From Food • Obligate aerobes- Requires oxygen to survive • Obligate anaerobes- Live only without oxygen • Facultative anaerobes- Can live in the presence of oxygen or without oxygen

Growth and Reproduction • Bacteria grow and reproduce at a very fast rate –Binary fission- Dividing in half forming two identical cells • Some bacteria can exchange DNA with other cells in a process called conjugation –Causes genetic variation in the population

Bacteria in Nature • Decomposers- Organisms that break down organic matter in nature –Recycle nutrients and brake down wastes in the environment

Bacteria In Nature • Nitrogen fixers- Bacteria that converts atmospheric nitrogen to forms that plants can use –Rhizobium bacteria lives in the roots of legume plants and converts nitrogen to ammonia that plants can use.

Bacteria and Disease • Two ways bacteria cause disease –Damage tissue –Release toxins

Bacteria and Disease • Fighting Disease –Antibiotics- Kill or limit the growth of bacteria –Vaccines- Can boost the bodies immune system to prevent infection

Controlling Bacteria • Sterilization- Heating or using chemicals to destroy bacteria • Refrigeration- Keeping food cool to prevent bacterial growth • Canning- Heating food to sterilize it and then sealing the container to prevent new contact with bacteria

Virus • Particle of nucleic acid, protein, and lipids that infect living cells in order to reproduce • Typical virus- DNA or RNA surrounded by a protein coat called a caspid

Viral Infection • Bacteriophage- Virus that infects bacteria –Lytic infection- The virus infects the cell, copies itself, and causes the cell to burst –Lysogenic infection- a virus embeds its DNA into the DNA of the host cell and is replicated along with the host cells DNA

Viruses and Disease • Viruses attack and destroy certain cells of the body • Vaccines work to prevent viral infection by boosting the immune system of the host before infection

Common Viral Illnesses • Aids- HIV virus- Immune system • Hepatitis- Hepatitis A, B or C- Liver • Herpes- Genital herpes, cold sores, chicken pox- Varied regions of the skin

Virus and Cancer • Oncogenic viruses- Cause cancer –HPV- Cuases many cases of cervical cancer –Can get a vaccination for some strains of the virus

Types of Virus • Retrovirus- Copies DNA from RNA which is backward from normal. –Responsible for cancer and aids

Types of Virus • Prions- Small pieces of proteins that cause disease –Cuases • Scrappie • Mad Cow