Biology Bacteria Structure & Function

Bacteria - Prokaryotes

Learning the basics of Prokaryotes

Learning Targets

1. I can compare the characteristics of the taxonomic groups Archaea and Bacteria2. I can compare and contrast prokaryotic and eukaryotic cells 3. I can describe the basic structures and functions of bacteria 4. I can analyze how bacteria respond to external factors

Prokaryotes are divided into 2 Domains

Each type of Prokaryote has a unique name, which is compsed of Genus and species Example: Escherichia coli or E. coli

Prokaryotes are not Eukaryotes

• Mouse over each picture to see

Eukaryotes

Prokaryotes

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Bacteria Structures

Click each organelle to see their function

Cell Membrane

Cytoplasm

Cell Wall

DNA (Circular)

Ribosomes

Pili

Flagella

Endospore - When times are desperate

• Thick walled structure that forms around chromosomes to protect it from harsh conditions
• lack of nutrients
• drought
• extreme temperatures
• radiation
• chemicals
• Endospores can protect it from disinfectants

Watch

Nutrition & Way of Life

• Nutrition:
• Chemoautotroph - makes energy from inorganic compounds
• Photoautotroph - makes energy from light
• Heterotroph - obtain energy from the environment

• Metabolic activity can be anaerobic or aerobic
• They can clump together to form strands

3 Shapes of Bacteria - Usually included in their name

Click each pic to read a little more about that shape

Cocci - Round

Bacilli - Rod

Spirillum - Spiral

Not all bacteria are harmful

Some types of bacteria are benefical

• Food production
• ex. cheese, yogurt, beer
• Nitrogen fixation
• occurs in plants
• Clean the environment
• used to clean oil spills
• Decomposers
• Recycle nutrients back into the soil
• Digestion
• help some organisms (cows, humans) with digestion

But sometimes bacteria can be harmful

• Some bacteria can metabolize their host They secrete enzymes that break down tissue for nutrition
• Ex—tuberculosis, anthrax, dental cavities, lyme disease
• Some bacteria secrete toxins
• Clostridium botulinum causes Botulism: a deadly toxin that can affect the nervous system, transmitted by contaminated can food. Person has double vision and paralysis. People with botulism may die because they are unable to breathe
• Staphlococcus aureus causes food poisoning; nausea, vomiting, diarrhea -painful but not usually fatal

Click on the link below to learn about bacterial reproduction. **You will have to find space on your notes for this.

Bacterial Reproduction Slide

Thank you!