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Life. Individual survival Take in, digest nutrients Eliminate wastes Recognize self from non-self Recognize enemies Repair damage Reproduction Survival of species Gene transfer. Eukaryotes. Prokaryotes. US. Vertebrates. Invertebrates. Plants. Animals. Algae. Fungi. Protozoa.
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Life • Individual survival • Take in, digest nutrients • Eliminate wastes • Recognize self from non-self • Recognize enemies • Repair damage • Reproduction • Survival of species • Gene transfer
Eukaryotes Prokaryotes US Vertebrates Invertebrates Plants Animals Algae Fungi Protozoa Single-celled Archaea ? Bacteria UCA
Cell Functions • Maintenance • Recovery of energy from nutrients • Storage of energy • Synthesis of correct proteins and other cell components • Perpetuation of self • DNA replication • Cell division • Specialized functions • e.g. muscle, blood, nerve cells, immune system
The molecules of life • Nucleic acids (DNA, RNA) • Proteins • Carbohydrates • Lipids • Lipoproteins, glycoproteins, vitamins….
Genomics The Genome Transcriptome Translation Protein synthesis Transcription DNA RNA Protein The Proteome Proteomics DNA + DNA DNA Replication Cell division
PROTEINS • Chains of amino acids • Structural elements – • cell walls, membranes • Transport • Catalysts - enzymes • Communication - within cells, between cells • Cytokines • Signal transduction factors • Receptors • Vital for regulation of growth, cell division
Schematic metabolic cycle Cellular components Nucleic acids, Carbohydrates, Protein, Fat Metabolic intermediates Food Carbohydrates, Fats, Glucose, Proteins NADP+ NADPH ADP + Pi ATP Work TransportAssemblyMovementHeat ATP NAD+ NAD+ NADH NADH ADP + Pi Wastes CO2, H2O, lactic acid The Metabolome - Metabolomics
Viruses • 0.02-0.3 micrometers diameter • Genetic material: ss or ds DNA, RNA • Protein coat • Some enzymes • Lipid envelope – enveloped/non enveloped viruses • Shape: rods, spheres, icosahedra, irregular • Nomenclature semi-systematic • Hepatitis A Virus, HAV • Need host cell for replication
The plasma membraneLipid bilayer Glycolipid Glycoprotein Av. Width 7.5 nm (75 Å) Sugar Polar Non-polar (Lipid) Protein
Envelope: lipid bilayer membrane + glycoproteins, typically acquired from host cell membranes • Capsid (protein coat): multiple copies of 1 or more proteins
The Flu Virion Lipid bilayer envelope Hemagglutinin Matrix protein Neuraminidase
Life-cycle of virus • Particle, virion • Infects host cell • Genetic material uses host’s replication apparatus to produce new viral components (capsid, core proteins, genetic material) • Components assemble into viral particles, exit host cell, sometimes lysing host cell
Each type of virus has its own specific host • Viruses that colonize bacteria are bacteriophage viruses (bacteriophages).
Unicellular organisms • Bacteria - procaryotes • Protozoa • Algae - eucaryotes • Fungi
Procaryotes: Bacteria and Others Unicellular organisms Simple internal organization Multiply by binary fission Diameter ~0.5-1.0 micrometer Envelope: cytoplasmic membrane, cell wall & capsule (polysaccharide) Some form biofilm (secrete polymeric matrix) Some have appendages: flagella: for locomotion pili: attachment to other cells for genetic transfer;virus receptor site Standard Linnean nomenclature: Genus species
Diverse bacteria Gram positive Gram negative
More bacterial types • Aerobes • Anaerobes • Facultative aerobes • Rods (bacilli) • Spherical (cocci) • Comma-shaped (vibrios) • Spiral (spirochetes)
Bacteria in the Environment Some bacteria form spores: • highly resistant to physical and chemical agents and • very persistent in the environment
Unicellular Eucaryotes: • More complex internal organization: • organelles: discrete nucleus, mitochondria • Wide range of sizes: 2 micrometers and larger
Protozoa • Unicellular; non-photosynthetic; flexible cell membrane; no cell wall; some are parasites, have complex life-cycles • Wide range of sizes and shapes; 2 micrometers to 2 mm • Disease-causing: • Amoebae: Entamoeba histolytica • Flagellates: Giardia lamblia • Ciliates: Balantidum coli • Sporozoans: Plasmodium vivax • Coccidians: Cryptosporidium parvum • Microsporidia: Cyclosopora cayetanensis
Cryptosporidium parvum oocysts: ~5 m diameter Wet mount by differential interference contrast microscopy Acid fast stain of fecal preparation
More Protozoans: Fungi • Fungi (yeasts and molds): • non-photosynthetic • immotile; • rigid cell wall • Molds: • grow as branched, interlacing chains or filaments (hyphae) called mycelia • Yeasts: • do not form mycelia • grow as single cells that bud • sexual reproduction possible Mitospores (conidia) of Penicillium, one of the asexual Ascomycota Yeasts
Algae • Photosynthetic • Rigid cell wall • Simple plants, protists, protozoa, plancton, derived from cyanobacteria ? • Wide range of sizes and shapes • 2 micrometers and larger • Some algae are harmful • Algal booms • Toxins • Anabaena, anatoxins Nostoc
Helminths (Worms) • Multicellular animals • Some are human and/or animal parasites • Eggs pass via human and animal excreta to water, food, soil. • Several major groups: • Roundworms, Nematodes eg. Ascaris, Trichinella spiralis, hookworms • Flatworms Platyhelminthes: Cestodes (tapeworms): pork, beef tapeworms, and Trematodes (flukes) eg Schistosomes • Annelids (leeches) Necator (hookworm) eggs adult
Eggs hatch in soil • Infective stage: larvae • Penetrate skin, migrate to blood, lungs, trachea • or are ingested • Adults mature in intestine • Attach to intestinal walls • anemia • Necator americanus , Ancylostoma duodenale(hookworm)
Schistosomes (blood flukes) Liver fluke Trematodes
Cestodes • Head (scolex) attaches to tissue • beef tapeworm, Taenia saginata • pork tapeworm (T. solium) • Grows in intestine http://www.marvistavet.com/html/body_tapeworm.html
Multicellular organisms • Plants • Animals • Invertebrates • Vertebrates