Bacteria: Classification and Structure

What are the 6 Kingdoms? Archaebacteria Archaebacteria Eubacteria Eubacteria Protists Protists Fungi Fungi Plants Plants Animals Animals

We are looking at the first two Archaebacteria : Extremists. Eubacteria: Larger of the two kingdoms. Contain a variety of organisms

Archaebacteria Live in extreme locations: Live in extreme locations: Oxygen-free environments Oxygen-free environments Concentrated salt-water Concentrated salt-water Hot, acidic water Hot, acidic water

EUBACTERIA Bacteria – all are prokaryotic meaning they do not have a nucleus.  Bacteria are unicellullar cells (one cell only)  They are found almost everywhere: -water-air -soil-food -skin-inside the body -on most objects

Clean skin has about 20 million bacteria per square inch

The tip of a needle The red and yellow dots are bacteria

Structure of Bacteria Two parts to Bacteria Structure: Two parts to Bacteria Structure: Arrangement Arrangement Shape Shape

Spiral: spirilla rod-shaped: bacilli, bacillus Round: cocci 3 Shapes of Bacteria Bacteria are classified by shape into 3 groups:

7 Major parts of a Bacteria Cell Capsule Cell wall Ribosomes Nucleoid Flagella Pilli Cytoplasm

Capsule CAPSULE  keeps the cell from drying out and helps it stick to food or other cells

Cell wall CELL WALL  Thick outer covering that maintains the overall shape of the bacterial cell

Cell Wall – determined by Gram Staining. Gram positive – stain purple because they have peptidoglycan in their cell wall. Thicker cell wall, but less pathogenic.. Gram negative – stain red because they lack peptidoglycan in their cell wall. Thinner cell wall, but generally more pathogenic.

Penicillin kills bacteria by making holes in their cell walls. Unfortunately, many bacteria have developed resistance to this antibiotic. Penicillin kills bacteria by making holes in their cell walls. Unfortunately, many bacteria have developed resistance to this antibiotic.walls

Ribosomes RIBOSOMES  cell part where proteins are made  Ribosomes give the cytoplasm of bacteria a granular appearance in electron micrographs

Nucleoid NUCLEOID  a ring made up of DNA

Pilli PILLI  hollow hair-like structures made of protein  allows bacteria to attach to other cells.  Pilli-singular  Pillus-plural

Flagella FLAGELLA  a whip-like tail that some bacteria have for locomotion

Classification Movement Movement Non-motile Non-motile Flagella – whiplike structure Flagella – whiplike structure Gliding – secrete a slime Gliding – secrete a slime

Cytoplasm CYTOPLASM  clear jelly-like material that makes up most of the cell

Metabolic Diversity Chemoheterotrophs: - take in organic molecules for energy. Chemoheterotrophs: - take in organic molecules for energy. Photoheterotrophs: - use sunlight and photosynthesis for energy but must also take in organic molecules for energy. Photoheterotrophs: - use sunlight and photosynthesis for energy but must also take in organic molecules for energy. Photoautotrphs:- Use sunlight energy and photosynthesis to make their own food. Photoautotrphs:- Use sunlight energy and photosynthesis to make their own food. chemoautotrophs: - use carbondioxide to make energy but do not require light. chemoautotrophs: - use carbondioxide to make energy but do not require light.

Energy Release Oblique aerobes: require oxygen for life. Example: Mycobacterium tuberculosis Oblique aerobes: require oxygen for life. Example: Mycobacterium tuberculosis oblique anaerobes: must live in the absence of oxygen. Example: Clostridium botulinum oblique anaerobes: must live in the absence of oxygen. Example: Clostridium botulinum Facultative anaerobes: Can live with or without oxygen. Example: Escherichia coli Facultative anaerobes: Can live with or without oxygen. Example: Escherichia coli

Binary Fission- the process of one organism dividing into two organisms Fission is a type of asexual reproduction Reproduction of Bacteria How?... The one main (circular) chromosome makes a copy of itself Then it divides into two Asexual reproduction- reproduction of a living thing from only one parent

BINARY FISSION Bacteria dividing Completed Reproduction of Bacteria

The time of reproduction depends on how desirable the conditions are Bacteria can rapidly reproduce themselves in warm, dark, and moist conditions Some can reproduce every 20 minutes (one bacteria could be an ancestor to one million bacteria in six hours) Reproduction of Bacteria

Bacterial Cell & Nucleiod DNA Ring DNA replication Cell wall synthesis Cell separation

Spore formation Endospore- a thick celled structure that forms inside the cell they are the major cause of food poisoning they can withstand boiling, freezing, and extremely dry conditions it encloses all the nuclear materials and some cytoplasm allows the bacteria to survive for many years

Bacillus subtilis Endospore-the black section in the middle  highly resistant structures  can withstand radiation, UV light, and boiling at 120oC for 15 minutes. Bacteria Survival

Bacteria Survival – Nutrition parasites – bacteria that feed on living things saprophytes – use dead materials for food (exclusively) decomposers – get food from breaking down dead matter into simple chemicals important- because they send minerals and other materials back into the soil so other organisms can use them

Harmful Bacteria some bacteria cause diseases Animals can pass diseases to humans Communicable Disease – Disease passed from one organism to another This can happen in several ways: Air Touching clothing, food, silverware, or toothbrush Drinking water that contains bacteria

Human tooth with accumulation of bacterial plaque (smooth areas) and calcified tartar (rough areas) Harmful Bacteria

Helpful Bacteria (Importance of bacteria) Decomposers help recycle nutrients into the soil for other organisms to grow Bacteria grow in the stomach of a cow to break down grass and hay (cellulose) Most are used to make antibiotics Some bacteria help make insulin Used to make industrial chemicals

E.coli on small intestines 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 & Swiss cheese, sour cream, buttermilk are made from bacteria that grows in milk Helpful Bacteria

Controlling Bacteria 3 ways to control bacteria: 1) Canning- the process of sealing food in airtight cans or jars after killing bacteria endospores are killed during this process 2) Pasteurization- process of heating milk to kill harmful bacteria 3) Dehydration- removing water from food Bacteria can’t grow when H 2 O is removed example: uncooked noodles & cold cereal

Controlling Bacteria Antiseptic vs. Disinfectants Antiseptic- chemicals that kill bacteria on living things means – “against infection” Examples: iodine, hydrogen peroxide, alcohol, soap, mouthwash Disinfectants- stronger chemicals that destroy bacteria on objects or nonliving things

37 Summary on the structure of bacteria StructureFunction Cell Wall Protects and gives shape Outer Membrane Protects against antibodies (Gram Neg. Only) Cell Membrane Regulates movement of materials, contains enzymes important to cellular respiration Cytoplasm Contains DNA, ribosomes, essential compounds Chromosome Carries genetic information Plasmid Contains some genes obtained through recomb. Capsule & Slime Layer Protects the cell and assist in attaching cell to other surfaces Endospore Protects cell agains harsh enviornments Pilus Assists the cell in attaching to other surfaces Flagellum Moves the cell

Bacteria and Diseases. Some bacteria cause diseases --Disease causing bacteria are called PATHOGENS.

Bacteria and Disease DiseasePathogen Areas affected Mode of transmission Botulism Clostridium botulinum Nerves Improperly preserved food Cholera Vibrio cholerae Intestine Contaminated water Dental Caries Streptococcus mutans, sanguis, salivarius Teeth Environment to mouth Gonorrhea Neisseria gonorrhoeae Urethra, fallopian Sexual contact Lyme disease Berrelia burgdorferi Skin, joints Tick bite Rocky Mountain SF Rickettsia recketsii Blood, skin Tick bite SalmonellaSalmonellaIntestine Contaminated food, water Strep throat Streptococcus pyogenes URT, blood, skin Sneezes, coughs, etc. Tetanus Costridium tetani Nerves Contaminated wounds Tuberculosis Mycobacterium tuberculosis Lung, bones coughs

Leprosy is a bacterial infection that decreases blood flow to the extremities resulting in the deterioration of toes, ears, the nose and the fingers.

DENTAL CARIES

CHOLERA

ROCKY MOUNTAIN SF

LYME DISEASE

SALMONELLA

STREP THROAT

TETANUS

TUBERCULOSIS

Plants, Fungi & Animal Cells Plants Only Plants Only Cell wall of cellulose Cell wall of cellulose Central vacuole Central vacuole Chloroplasts Chloroplasts Animals Only Animals Only Lysosomes Centrioles Fungi Only –Cell wall of chitin –Central vacuole –No chloroplasts