BACTERIA AND ARCHAEA

YOU MUST KNOW… THE KEY WAYS IN WHICH PROKARYOTES DIFFER FROM EUKARYOTES WITH RESPECT TO GENOME, MEMBRANE-BOUND ORGANELLES, SIZE, AND REPRODUCTION

CONCEPT 27.1 STRUCTURAL AND FUNCTIONAL ADAPTATIONS CONTRIBUTE TO PROKARYOTIC SUCCESS

3 DOMAINS ARCHAEA BACTERIA EUKARYA ARCHAEA AND BACTERIA ARE PROKARYOTES

PROKARYOTES - NO TRUE NUCLEI OR INTERNAL COMPARTMENTALIZATION DNA IS IN A NUCLEOID REGION SMALL GENOMES, ONE MAJOR CHROMOSOME AND SMALLER, CIRCULAR, INDEPENDENT PIECES OF DNA CALLED PLASMIDS CELL WALL CONTAINING PEPTIDOGLYCANS GRAM-POSITIVE – CELL WALL WITH PEPTIDOGLYCANS GRAM-NEGATIVE – MORE COMPLEX CELL WALLS PILI – ADHERE TO SURFACES MAY HAVE FLAGELLA – FOR MOVEMENT

CONCEPT 27.2 RAPID REPRODUCTION, MUTATION, AND GENETIC RECOMBINATION PROMOTE GENETIC DIVERSITY IN PROKARYOTES

3 MECHANISMS OF GENETIC MATERIAL TRANSFER TRANSFORMATION – PROKARYOTE TAKES UP DNA FROM ITS ENVT CONJUGATION – GENES ARE DIRECTLY TRANFERRED FROM ONE PROKARYOTE TO ANOTHER TRANSDUCTION – VIRUSES TRANSFER GENES BETWEEN PROKARYOTES MUTATION – THE MAJOR SOURCE OF GENETIC VARIATION IN PROKARYOTES

CONCEPT 27.3 A GREAT DIVERSITY OF NUTRITIONAL AND METABOLIC ADAPTATIONS HAS EVOLVED IN PROKARYOTES

4 GROUPS OF PROKARYOTES PLACED IN FOUR GROUPS ACCORDING TO HOW THEY TAKE IN CARBON AND HOW THEY OBTAIN ENERGY

PHOTOAUTOTROPHS – PHOTOSYNTHETIC, USE POWER OF SUNLIGHT TO CONVERT CARBON DIOXIDE INTO ORGANIC COMPOUNDS CHEMOAUTOTROPHS – USE CARBON DIOXIDE AS THEIR SOURCE OF CARBON BUT THEY GET THEIR ENERGY FROM OXIDIZING INORGANIC SUBSTANCES

PHOTOHETEROTROPHS – USE LIGHT TO MAKE ATP BUT MUST OBTAIN THEIR CARBON FROM AN OUTSIDE SOURCE ALREADY FIXED IN ORGANIC COMPOUNDS CHEMOHETEROTROPHS – GET BOTH CARBON AND ENERGY FROM ORGANIC COMPOUNDS

OBLIGATE AEROBES – CANNOT GROW WITHOUT OXYGEN BECAUSE THEY NEED OXYGEN FOR CELLULAR RESPIRATION OBLIGATE ANAEROBES – POISONED BY OXYGEN, USE FERMENTATION FACULTATIVE ANAEROBES – USE OXYGEN IF AVAILABLE BUT CAN USE FERMENTATION IF NO OXYGEN SOME PROKARYOTES CAN USE NITROGEN AFTER NITROGEN FIXATION

CONCEPT 27.4 MOLECULAR SYSTEMATICS IS ILLUMINATING PROKARYOTIC PHYLOGENY

EXTREMOPHILES FIRST PROKARYOTES (ARCHAEA) EXTREME HALOPHILES – LIVE IN SALINE ENVTS EXTREME THERMOHILES – LIVE IN VERY HOT ENVTS OTHER ARCHAEA DO NOT LIVE IN EXTREMES METHANOGENS USE CARBON DIOXIDE TO OXIDIZE H2 AND PRODUCE METHANE AS A WASTE PRODUCT

CONCEPT 27.5 PROKARYOTES PLAY CRUCIAL ROLES IN THE BIOSPHERE

DECOMPOSERS – BREAKING DOWN DEAD CORPSES, VEGETATION, AND WASTE PRODUCTS SYMBIOTIC – FORM RELATIONSHIPS WITH OTHER SPECIES MUTUALISM – BOTH SYMBIOTIC ORGANISMS BENEFIT COMMENSALISM – ONE BENEFITS AND THE OTHER IS NEITHER HELPED OR HARMED PARASITISM – ONE ORGANISM BENEFITS AT THE EXPENSE OF THE OTHER

CONCEPT 27.6 PROKARYOTES HAVE BOTH HARMFUL AND BENEFICIAL IMPACTS ON HUMANS

SOME PROKARYOTES ARE PATHOGENIC AND CAUSE ILLNESS BY PRODUCING TOXINS ANTIBIOTICS – CHEMICALS THAT CAN KILL PROKARYOTES

USES OF PROKARYOTES BIOREMEDIATION – REMOVING POLLUTANTS FROM SOIL, AIR, OR WATER (TREATING SEWAGE, CLEANING UP OIL SPILLS) SYMBIONTS IN THE GUT (MAKE VITAMINS, DIGEST FOODS) GENE CLONING AND PRODUCING TRANSGENIC ORGANISMS PRODUCTION OF CHEESE AND YOGURT