Structure and Function Bacteria Structure and Function

Prokaryotic & Eukaryotic Cells

Characteristics of Bacteria

Bacterial Structure Microscopic prokaryotes No nucleus or membrane-bound organelles Contain ribosomes Single, circular chromosome in nucleoid region

Bacterial Cell

Protection Cell Wall made of Peptidoglycan May have a sticky coating called the Capsule for attachment to host or other bacteria

Sticky Bacterial Capsule

Bacterial Structure Have small rings of DNA called Plasmids Unicellular Small in size (0.5 to 2μm) PLASMIDS

Bacterial Structure Infoldings of cell membrane carry on photosynthesis & cellular respiration Infoldings called Mesosomes

Mesosomes MESOSOME

Bacterial Structure Most grow best at pH of 6.5 to 7.0 Many act as decomposers recycling nutrients Some cause disease

Flagella Bacteria that are motile have appendages called flagella Attached by Basal Body A bacteria can have one or many flagella

Flagella Made of Flagellin Monotrichous: 1 flagella Used for Classification Monotrichous: 1 flagella Lophotrichous: tuft at one end Amphitrichous: tuft at both ends Peritrichous: all around bacteria

Monotrichous Lophotrichous Amphitrichous Peritrichous

What is this type of bacteria ? Question: What is this type of bacteria ?

Pili Short protein appendages Smaller than flagella Adhere bacteria to surfaces Used in conjugation for Exchange of genetic information Aid Flotation by increasing buoyancy

Pili in Conjugation

Reproduction Bacteria reproduce asexually by binary fission Single chromosome replicates & then cell divides Rapid All new cells identical (clones)

Cellular organism copies it’s genetic information then splits into two identical daughter cells