2 Diversity of life ArchaebacteriaEubacteriaProtista Biological Kingdoms
3 Diversity of life FungiPlantaeAnimalia Biological Kingdoms
4 Diversity of life Kingdoms Archaebacteria Eubacteria ProtistaFungiPlantaeAnimalia Methanogens Bacteria Protozoans Amoebas Slime molds Molds Yeasts Mushrooms Rusts Smuts Mildew Toadstools Algae Red Brown Green Moss Ferns Vascular plants Sponges Jellyfish Hydras Planaria Worms Snails Insects Fish Reptiles Birds Mammals 100,00025,00030,000520,0001,080,000 No. of species:
5 Naming of organisms allows scientists to communicate unambiguously about organisms being studied binomial nomenclature used: Genus species names are in Latin and are written in italics or underlined (to denote a foreign word)
6 Naming of organisms names often denote a property of the organism or something about its discovery: substrate utilizedSaccharomyces product producedClostridium acetobutylicum preferred temperatureStreptococcus thermophilus colorAspergillus niger sizeBacillus megaterium discovererTrichoderma reesei geographic locationLactobacillus sanfrancisco
8 Cell size Cells range in size from 5-20 μm to 5 cm long. Most cells are small because larger cells do not function as efficiently. As cell size increases, volume increases more rapidly than surface area. Larger cells have less surface area per unit volume, thus less opportunity to interact with the environment. Cytoplasm fills cell interior.
9 Plasma membrane All cells contain a plasma membrane Encloses cell and separates contents from surroundings. Phospholipid bilayer with embedded proteins. Cell Surface Proteins – Act as markers to identify particular types of cells. Transmembrane Proteins – Span entire membrane. Provide channels for molecule passage.
12 Proteins in membrane structures Nonpolar regions of a protein lock it into the lipid bilayer of the membrane
13 Types of cell structures Procaryotic do not have a nuclear membrane includes species from the kingdoms Archaebacteria and Eubacteria Eucaryotic possess nuclear membrane contain organelles 1,000 to 10,000 times larger than procaryotic cells includes species from all kingdoms except Archaebacteria and Eubacteria
14 Comparison of Procaryotic and Eucaryotic Organisms ProcaryotesEucaryotes Organismsarchaebacteria, bacteriaprotists, fungi, plants, animals Cell linear dim.1-10 :m10-100 :m Metabolismanaerobic or aerobicaerobic or anaerobic Organellesnonucleus, chloroplasts, mitochondria, endoplasmic reticulum, etc. DNAcircular, in cytoplasmvery long linear molecules bounded by nuclear envelope RNA and proteinRNA and protein synthesized in same compartment RNA synthesized in nucleus; protein, in cytoplasm Cytoplasmno cytoskeleton: no cytoplasmic streaming, no endocytosis, no exocytosis cytoskeleton composed of protein filaments; cytoplasmic streaming; endocytosis and exocytosis Cell divisionchromosomes pulled apart by attachment to plasma membrane chromosomes pulled apart by cytoskeletal spindle apparatus Cellular organization mainly unicellularmainly multicellular, with differentiation of many cell types Molecular Biology of the Cell, 2 nd Ed.
24 Eucaryotic cells Interior of eukaryotic cell contains numerous membrane-bound structures (organelles) that close off compartments to allow multiple simultaneous biochemical processes. Eucaryotic cells also have a cytoskeleton – a dense network of protein fibers supporting cell shape.
27 Cell Organelles Eukaryotic cells thought to have evolved from endosymbiosis between different species of prokaryotes. Engulfed prokaryotes provided hosts with certain metabolic advantages.
28 Nucleus Nucleus - Command and control center. Bound by nuclear envelope. Nuclear pores filled with proteins permit passage of material in and out of the cell. Contain chromosomes holding DNA. Nucleolus - Cluster of genes within nucleus encoding rRNA. Ribosome reads RNA and directs protein building.
30 Nucleus As a cell prepares to divide, DNA coils around histones (packaging proteins) into a highly condensed form, a nucleosome.
31 Endoplasmic Reticulum Internal membrane creating channels and membrane-enclosed vesicles. Carbohydrates and lipids manufactured on the surface. Proteins for export produced on surface covered with ribosomes (Rough ER).
33 Ribosomes Ribosomes are the site of protein synthesis. Made up of rRNA bound within complex of several dozen different proteins. Composed of two subunits that join to form a functional ribosome only when they attach to messenger RNA. Assembled in nucleolus within the nucleus.
34 Golgi Apparatus Collection of interconnected flattened stacks of membranes (Golgi bodies). Function in collection, packaging, and distribution of molecules synthesized in one place, and utilized in another place within the cell.
36 Vesicles Lysosomes – Membrane-bound digestive vesicles that arise from Golgi apparatus. Contain degrading enzymes that break down old organelles and other structures. Microbodies – carry enzymes. Glyoxysome – Convert fat into carbohydrates (Plants). Peroxisome – Catalyze removal of electrons and associated hydrogen atoms.
38 Organelles With DNA Mitochondria Contain own DNA. Double membrane organelles that extract energy from organic molecules. (Oxidative Metabolism) Inner membrane bent into numerous folds (cristae) that partition mitochondrion into inner matrix and outer compartment.
41 Organelles With DNA Chloroplasts Double membrane organelles that serve as site of photosynthesis. Contain chlorophyll, a photosynthetic pigment that gives most plants their green color. Inner membranes fused to form stacks of thylakoids, which contain light-capturing pigments. Thylakoids stacked on top of one another to form a column (granum). Interior bathed with a semiliquid (stroma).