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Types of Heterotrophic Nutrition. Methods of Feeding. Saprophytic Nutrition feed on dead organic matter, get energy from it, and recycle it back into the environment. decomposers. Parasitism organism (parasite) feeds off of another (host) at the expense of the host. Predation - PowerPoint PPT Presentation
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Types of Heterotrophic Nutrition
Methods of Feeding1. Saprophytic Nutrition
– feed on dead organic matter, get energy from it, and recycle it back into the environment.• decomposers.
2. Parasitism– organism (parasite) feeds off of another (host) at the expense of
the host.
3. Predation– - organism (predator) hunts, kills, and eats another organism
(prey).
4. Scavenging– feed on organisms killed by something else.
What are Bacteria?• Bacteria are PROKARYOTES–The smallest known living cells
They are found everywhere!! Bacteria on
head of a pin Starr, 317
Bacteria in dental plaque microbeworld.org
Did you know? There are over 80 species of bacteria in your mouth!
Obtaining Energy• Autotrophs (make energy)– Photoautotrophs- capture energy
from light• Ex- cyabobacteria
– Chemiautotrophs- obtain energy from chemical reactions with inorganic molecules (ammonia, hydrogen sulfide, nitrites, sulfur, Iron)• Ex. Ocean vent bacteria
Cyanobacteria bloom
Obtaining Energy cont…
• Heterotrophs- most bacteria obtain their energy from organic molecules– These bacteria are often feeding in, on and
around us…• Some bacteria are photoheterotrophs– Capture sunlight and digest organic molecules
Releasing Energy• Bacteria can use both cell respiration and
fermentation• Many bacteria have different oxygen
requirements:– Obligate aerobes- must have oxygen for respiration– Facultative anaerobes- can function with or without
oxygen– Obligate anaerobes- poisoned by oxygen (use
fermentation)
Three basic shapes of Bacteria
• Spherical – coccus
• Rod – bacillus• Coiled - spirillum
Schraer, 633
Shapes of Bacteria
Coccus
• Spheres• Cocci (plural) • a variety of arrangements
Diplobacillus (paired)
Bacillus • Cylindrical or rod-shape • Bacilli (plural) • Variations in cell arrangement
Spirals
• Vibrio• Spirillum• Spirochete
Simple Colonies Staphylo = clusters
Strepto = chains
Staphylococcus wisc.edu
Diplo = double
Diplococcus cat.cc.md.us
Streptobacillus
Some have flagella - made of rope-like proteins, not microtubules.
Some slide on a slimy secretion.
Many can form dormant
cells called endospores to survive harsh conditions.
Salmonella www.iwate.jp
Streptomyces spores
Many can MOVE
Bacterial Reproduction
• Bacterial cells reproduce asexually through fission which is the splitting of a cell into two new cells.
Bacterial Reproduction cont…• Some bacteria utilize conjugation to
exchange pieces of genetic information to increase variation– *Not considered sexual reproduction- not
complete exchange of DNA, no offspring made