Microbiology

Early life did not use O2. CO2 was used. The gas mixture back then (hypothesized) was CH4, NH3, and H2.

The origin of RNA is linked to clay and molecular bonding. The minerals in clay could have been used to to build larger molecules. Iron pyrite and other minerals in clay release electrons, giving energy to form bonds, and clay minerals may have also acted as catalysts. RNA is thought to have formed on the surface of clay, adenine attracted uracil, a hydrogen bond forms, and the clay releases the double strand of UA. RNA stores genetic info to make its own proteins, catalyses chemical rxns, duplicates itself.

Lipids form membrane like structures in the right conditions. pieces of membrane would break free from their structures and create a bubble.

All life forms were aquatic until land based organisms began using sunlight for energy. Original aquatic photosynthesis used H2S and excreted sulfur. New photosynthesis required h2o and produces oxygen.

anaerobic - without oxygen

nucleiod - contain DNA

plasmids - free floating DNA rings

pilus - allow bacteria to stick to surfaces and other cells

  • sex pilus exchange DNA with other cells

endospores - shell that protects bacteria from dying in almost any circumstances

autotroph - requires carbon from inorganic sources, makes its own food

heterotroph - acquire carbon from other life forms

phototroph - take energy from the sun

chemotroph - derive energy from oxidizing in/organic chemicals

aerobe - use O2 to produce ATP

anaerobe - can produce ATP without O2

  • obligate - killed by oxygen

  • calculated - can live in any environment

Prokaryote

Single celled organism with no nucleus or membrane bound organelles. Bact. and Aracha. have similar internal structures. Different chemical makeup. Decompose organic material, release CO2.

Bacteria

proteobacteria is the most diverse group. Cyanobacteria are the photosynthesizers, the first O2 producers, make up some photosynthetic plankton, and make symbiotic relationships with land fungi.

endospore - dormant, thick-walled structures surrounding DNA and a small amount of cytoplasm

plasmids - circles of DNA located away from the chromosome, genes encode proteins needed to copy that plasmid, resist antibiotics/toxins, cause disease, alter cell metabolism

  • circular chromosomes

  • unicellular

  • Nucleoid contains DNA, RNA, and some proteins

  • (some) can fix nitrogen or grow at 80+ degrees ( chemical rxn in which prokaryotes convert atmospheric nitrogen gas into ammonium (NH4) to allow plant and organisms to absorb it

  • cell wall made of peptidoglycan

  • membrane based of fatty acids

  • cannot generate methane

  • Some use chlorophyll

  • Genes do not contain introns

Archaea

  • circular chromosomes

  • unicellualr

  • (some) can fix nitrogen or grow at 80+ degrees

  • cell wall composed of proteins

  • do not use chlorophyll

  • cell wall - protein

Cell walls

Coccus - round

Bacillus - rod-like

Spirillum - spiral

endosymbiotic theory - in-folding of the membrane gave rise to organelles. The infolding of photosynthetic bacterium begat photosynthetic eukaryotes (plant cells).

endosymbiont theory - the mitochondrion and chloroplast organelles of eukaryotic cells originated as free-living bacteria

The first multicellular organisms (chlamydomonas) are thought to have joined together to form the volvox. Purpose unknown, but likely for survival.

Multicellularity - 1.2 BYA, rose independently in ,multiple lineages.

Protists - capable of photosynthesis,

  • Algae

    • Look like plant cells, photosynthetic, component of plankton

    • Diatoms - algae with unique silica cell walls

    • Brown algae - most complex/largest protists

    • Red or Green - share features with plants

  • Slime/water mold

    • Look like fungal cells, heterotrophic

    • decomposer

    • like moisture

    • produce filaments that secrete digestive enzymes in their surroundings

    • contain cellulose

  • Protozoa

    • Look like animal cells

  • Dinoflagellates

    • Have 2 flagella

    • Similar to animal cells

  • Amoeboid

    • Produce pseudopodia for movement and food capture (NOT FLAGELLUM)

    • foraminiferans - ancient group of marine amoeboid protozoa. Have complex shells, and extremely popular

  • Ciliates

    • Complex Protozoa

    • Unicellular

    • Has cilia for movement and hunting

  • Apicomplexans

    • Nonmotile complexans

Fungus

Cannot do photosynthesis, share more chemical similarities with animals, heterotrophic, secrete the enzymes to break down sustenance outside of the organism then eat the nutrients, cell walls made of chitin, stores energy in glycogen, mostly multicellular

hyphae - microscopic filaments used to release digestive enzymes and absorb nutrients

Phyla

  • chytridiomycete - produce gametes and asexual spores with flagella

  • zygomycete - thick walled asexual spores with flagella

  • glomeromycete - large asexual spores, nearly visible to naked eyes

  • ascomycete - hyphae come together to form a fruiting body, produce sac-like sexual spores

  • basidiomycete - hyphae come together to form a fruiting body, produce club-like sexual spores

endophytes - fungi that live between the cells of a plant’s tissues without disease making

mycorrhizae - fungi in living roots, hyphae eaten