230 likes | 435 Views
Prokaryotes. Prokaryotes. Structure Cocci : Sphere, 1 micrometer Bacilli: Rod, 2 micrometer Spirilla : Spiral, 5 micrometer Gram Positive: simple walls, thick layer of peptidoglycan Gram Negative: complex walls, two membranes, thin layer of peptidogylcan. Gram Positive vs. Negative.
E N D
Prokaryotes • Structure • Cocci: Sphere, 1 micrometer • Bacilli: Rod, 2 micrometer • Spirilla: Spiral, 5 micrometer • Gram Positive: simple walls, thick layer of peptidoglycan • Gram Negative: complex walls, two membranes, thin layer of peptidogylcan
Prokaryotes • Antibiotics work by breaking down cell wall • Inhibits peptidoglycan linking together • Only affects prokaryotes and not eukaryotes • Eukaryotes don’t have peptidoglycans OR cell walls
Prokaryotes • Stick around: prokaryotes may rely on the ability to stay in host or location • Capsule: sticky layer outside of cell wall • Help adhere to surface • Protection • Fimbriae: hairlike that stick to surface • Short, many • Pili: hairlike that stick to surface • Long, few
Prokaryotes • Movement • Prokaryotes use flagella: tail like structure to create directional movement • Otherwise, they demonstrate taxis • Taxis: movement toward or away from stimulus
Prokaryotes • Do not have specialized organelles • Special membranes to conduct energy processes • Respiration • Photosynthesis
Prokaryotes • No nucleus, BUT a NUCLEOID REGION • DNA found in this region • DNA is a genetic ring: Prokaryotic chromosome • Smaller plasmids of DNA • Ribosomes are smaller in prokaryotes
Prokaryotes • Reproduction • Binary Fission: single parent divides into two daughter cells • Exponential growth • Slowed by antibiotics that inhibit reproduction
Prokaryotes • Rapid reproduction leads to faster evolution • More chances for mutation • More mutation means more opportunities for evolution • Prokaryotes and bacteria become antibiotic resistant over time • Fewer genes to mutate
Prokaryotes • Nutrition: different methods of creating energy • Photoautotrophs: use photosynthesis to make food and use Carbon from CO2 • Chemoautotrophs: use Carbon from CO2, use inorganic substances to make energy: ammonia, hydrogen sulfide
Prokaryotes • Photoheterotrophs: use photosynthesis, but need Carbon from organic source • Chemoheterotrophs: Carbon from organic source, make energy from inorganic substances.
Prokaryotes • Metabolism: based on Oxygen • Obligate aerobes: need use O2 for respiration but cannot grow without it. • Facultative anaerobes: can use O2 but can grow with out it through fermentation • Obligate anaerobes: poisoned by O2, live exclusively through fermentation
Prokaryotes • Nitrogen fixation: conversion of “fixed Nitrogen” into ammonia • Very important for Plant life • Metabolic cooperation also happens between prokaryotes so they can use their environment’s resources efficiently.
Prokaryotes • Proteobacteria: gram negative bacteria, anaerobic or aerobic • Alpha: eukaryotic hosts • Beta: important for nitrogen cycling/fixation • Gamma: E. Coli, and Salmonella • Delta: Slime Bacteria • Epsilon: pathogenic to humans
Prokaryotes • Chlamydias: parasites in animal cells • Spirochetes: free living, spiral shaped • Gram-positive bacteria: colony and individual bacteria • Cyanobacteria: plant like, lives in water, very important for marine ecosystems
Prokaryotes • Archaea Prokaryotes • Korarchaeotes • Euryarchaeotes • Crenarchaeotes • Nanoarchaeotes