Eubacteria

Structure 1 - Rigid cell wall: provides shape & protects cell 2 - No membrane-bound organelles = prokaryotes (do have ribosomes) 3 - Plasmids: (circular loops of DNA) and one simple chromosome

Structure 4 - Capsule: thick, protective layer many harmful bacteria have this to protect them from being digested by the hosts body fluids ex: bacteria that cause pneumonia and syphillis 5 - Other: flagella (tail for movement), pili (hairs used for attachment), and endospores

Structure

Nutrition Most are consumers - cannot make own food Saprobes: feed on dead organisms (organic waste); important in soil Parasites: absorb nutrients from another living organism (host)

Nutrition Mutualism: lives on or in another organism and both benefit; ex: intestinal bacteria and nitrogen-fixing bacteria

Respiration Obligate aerobe - requires oxygen for cellular respiration ex: bacteria that cause throat & lung infections such as TB Obligate anaerobe - does not use oxygen & may be harmed by it ex: tetanus (deep puncture wound) botulism

Respiration Facultative bacteria - can get energy using oxygen (cellular respiration) or by fermentation if oxygen is not available *ex: E. coli

Reproduction Asexual - binary fission -bacterial cell duplicates DNA & divides into two identical new cells

Reproduction Sexual - conjugation -bacterial cell transfers its chromosomes to another cell through a bridge-like structure called a pilus = genetic recombination “variety”

Growth Requirements 1 - temperature range (most degrees F) 2 - moisture (most are 90% water) 3 - darkness (sulight dries out & slows growth/ UV light damages DNA)

Growth 4 - food (variety - almost anything with carbon such as sugar, fat, protein, or blood) *some can metabolize inorganic material or even toxic substances 5 - correct oxygen requirements

Vocabulary Term Endospore - structure that forms when conditions are unfavorable (too dry, no food, etc.) - “hibernation state” - no reproduction occurs *some have lasted ~ 50 years in this state

Controlling Bacterial Growth -Refrigeration/Freezing -Canning (no oxygen) -Salt Curing -Dehydration -Radiation -Chemical Preservatives -Antiseptics

Importance to Life -Nitrogen fixing: found on plant roots, these bacteria convert free nitrogen into compounds that plants can use = natural fertilizer

Importance to Life -Food preparation: dairy products, pickles, olives, sauerkraut -Alcohol fermentation: producing beer & wine

Importance to Life -Aid digestion -Leather tanning: softens the hide

Importance to Life -Vaccines: use killed or weakened strains of bacteria & inject them into organisms so that antibodies are produced

Importance to Life -Wrinkle treatment: Botox -Genetic engineering: human hormones such as insulin, oil-eating bacteria, insect resistance in plants, digestion of toxic substances like DDT, etc.

Harmful Bacteria Cause disease Spoil food

Types of Food Poisoning Botulism -produces exotoxin (toxin produced by the bacterial cell during metabolism) which is harmful to humans -Usually found in improperly canned foods -Symptoms include dizziness, double vision, breathing difficulty & potentially, death

Types of Food Poisoning Botulism

Types of Food Poisoning Staphylococcus -Usually found in improperly stored meat, fish, & dairy products -Symptoms include vomiting & cramps

Types of Food Poisoning Salmonella - Usually caused by infected food handlers and found in food types such as eggs, sausage, ground meats, or custards -Symptoms include vomiting, cramps, diarrhea, aches & fever

Types of Food Poisoning Salmonella

Food Poisoning Prevention 1.Sanitary food handling techniques 2.Sterilization (canning) 3.Pasteruization 4.Refrigeration/Freezing 5.UV radiation

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