Prokaryotes

• heterotrophs -> photosynthetic autotrophs -> aerobes
• why is the plasma membrane folded inward?

  gives more surface area and faster respiration/photosynthesis
• what is the function of the cell wall?

  protection, maintains shape
• peptidoglycan: carbohydrate polymer, cell wall material for domain bacteria only
• eukarya cell wall made of cellulose
• what are the two types of bacterial cell walls?

  gram positive bacteria and gram negative bacteria
• archaea cell wall made of protein and other polysaccharides
• gram positive bacteria: thick wall, primarily peptidoglycan, retain crystal violet, don't see safranin, stains purple
• gram negative bacteria: thin peptidoglycan inner layer, lipopolysaccharide (LPS) outer membrane, does not retain crystal violet, safranin visible, stains pink
• gram negative often more likely to cause serious diseases
• taxis: directed movement in response to stimulus
• flagella: most common motility structure in prokaryotes, found in bacteria, archaea, eukaryotes
• procaryotic flagella is smaller than eukaryotic flagella, and different in mechanism and structure
• bacterial and archaeal flagella are similar in size and mechanism, but unrelated
• how do prokaryotes have genetic diversity?

  short generations and large populations
• transformation: prokaryotic cell takes up foreign DNA from environment
• recombination between cells: horizontal gene transfer
• conjunction: direct transfer of genetic material from one cell to another, usually the same species, involves F factor
• transduction: phages transfer prokaryotic genes from one cell to another
• phototrophs: energy from light
• chemotrophs: energy from chemicals
• autotrophs: only need CO2 or other inorganic carbon
• heterotrophs: require organic carbon
• prokaryotic metabolism varies with respect to O2
• obligated aerobes: must use O2
• obligated anaerobes: poisoned by O2, 2 alternatives
• what are the 2 alternatives for obligated anaerobes?

  fermentation (make ATP without ETC) and anaerobic respiration (ATP with ETC, different e acceptor)
• facultative anaerobes: use O2 when present, fermentation or anaerobic respiration when absent
• 2 groups of bacterial diversity: proteobacteria and cyanobacteria
• proteobacteria: large and diverse, 5 groups, mitochondria
• cyanobacteria: photoautotrophs - oxygenic photosynthesis, chloroplast
• archaeal diversity: thrive in extreme conditions
• halophiles: high salt environments
• thermophiles/hyperthermophiles: hot environments
• methanogens: release methane as a byproduct of metabolism, obligated anaerobes