BSC 2011C Lecture Notes - Lecture 12: Gram Staining, Genetic Recombination, Gram-Negative Bacteria
Document Summary
Are viruses alive: replicate, evolve, genotype/phenotype, no metabolism. Viral genes: force host to copy viral genome, force host to build protein coat, constantly evolving by natural selection. Viral structure: helical, icosahedral, complex, enveloped. Viruses infect specific host species via specific tissue. Lysogenic: viral dna integrates into host cell. Prokaryotes: no membrane bound nucleus, no organelles, no mitosis/meiosis, mostly asexual reproduction via binary fission. Gram stain: distinguishing between two species based on cell wall, gram positive: no extra membrane, gram negative: extra membrane, gram negative is more dangerous if pathogenic. Bacterial genome: small, dna in rinh, nucleoid, plasmid with self-replicating dna (antibiotic resistance) Prokaryotic reproduction: binary fission, no genetic recombination. Bacterial spores: allow bacterium to survive harsh conditions. Not enough mutation for bacteria to adapt to changing conditions via natural selection. Conjugation: exchange of plasmids and dna from donor to receiver. Transformation: prokaryotes absorb foreign dna through cell walls.
