chapter 2 microbial life Flashcards
cell membrane
cytoplasmic membrane
cell wall: bacteria and plants
- bacteria and archaea cell was is peptidoglycan
- plant cell wall is cellulose (sugar polymer)
macromolecules
proteins, nucleic acids, lipids, polysaccharides
macromolecule: proteins
peptide, made of amino acids
macromolecule: nucleic acids
found in cytoplasm
macromolecule: lipids
not strictly polymers (substance or material consisting of very large molecules called macromolecules)
macromolecule: polysaccharides
found in cell envelope, outer portion of prokaryotes
small organic molecules (found in cytoplasm)
- sugars
- fatty acids
- nucleotides
- amino acids
- other communication molecules
other elements of cell structure
inorganic ions, ribosomes, nucleus
prokaryotes have…
- nucleoid
- single chromosome
- circular
- haploid (one copy of each gene)
- extra chromosomal DNA (plasmid)
- fission
eukaryotes have…
- nucleus
- multiple chromosomes
- linear
- diploid/haploid
- mitosis and meiosis
viruses are…
- obligate “parasites”
- particles not cells
- needs a host
- unable to carry out independent metabolism
- no growth, small
- “degenerative cells” and “borrowed” components
three groups of cellular lineages
archaea, bacteria, eukarya
nomenclature
genus, species epithet
Escherichia coli (genus epithet)
must be italicized
evolutionary chronometer
evolutionary distance between two organisms can be measured by differences in nucleotide or amino acid sequence of monomers in homologous macromolecules (DNA, RNA, protein)
(standard chronometers are 16S and 18S rRNA)
physiological diversity
energy (ATP) is derived from 3 sources
- organic carbon (glucose)
- inorganic chemicals
- light
more physiological diversity
- CO2 is an inorganic carbon
- energy + carbon make up metabolism
- “fixed” is reduction, gaining energy, so add H bc they’re energy carriers
- CO2 to CH2O is carbon fixation
Chemoorganotrophs (organo-carbon)
bacteria, archaea, eukarya
chemolithotrophs (litho-rocks)
bacteria, archaea
phototrophs
bacteria, archaea, eukarya plants
photoheterotrophs
consumes carbon bc they don’t fix enough carbon with sunlight
carbon derived from two sources
inorganic and organic carbon
heterotrophs
organic carbon
autotrophs
inorganic carbon
fixes and grows its own carbon with sunlight and energy
prokaryotic diversity
bacteria
gram neg, gram pos, gram variable; relates to structure of cell envelope which is a phylogenetic characteristic of bacteria
gram stain
shows who’s related (+ to +, etc.)
proteobacteria
largest phylum, gram neg, extreme metabolic diversity, represents majority of known gram neg bacteria
gram pos bacteria
- includes endospore-forming bacillus and clostridia and streptomyces
- lactobacillus and streptococcus are important in dairy products and plant decay
bacillus
aerobic, spore forming, gram pos
clostridium
anaerobic, spore forming, gram pos
Mycoplasma
related to gram positives, but lack a cell wall (most are pathogenic)
Cyanobacteria
(related to gram positives) closely related to algae and higher plants
Green sulfur and green non sulfur
bacteria include photosynthetic organisms
Spirochetes
are medically important and have a unique morphology
Chlamydia
are obligate intracellular parasites
Aquifex and Thermotoga
are thermophiles
prokaryotic diversity
archaea
- more closely related to Eukarya than to bacteria
- all are chemotrophic and many are lithotrophic
- DNA floating around inside because prokaryotes don’t have a nucleus
- methanogens: unique metabolism, responsible for production of all natural gas
prokaryotic diversity
eukarya
- all multicellular life forms are Eukarya
- all “higher” Eukarya are in symbiotic relationships with prokaryotes
- many are microscopic, which includes: protozoa, fungi, algae, and slime molds
