The Basic Organization of Living Forms ESC 556 Environmental Biology Week 2
Fundamentals of Life Characteristics of Life Living matter vs. Inanimate matter Cellular organisation Nutrition Growth Respiration Responsiveness Movement Excretion Reproduction Catabolism vs. Anabolism
The Flame of Life Analogies Respire Nutrition Reproduce Excrete Grows Moves Responsiveness Organized Differences DNA/RNA Anabolic Metabolism
The Cell Smallest Unit of Life prokaryotic vs. eukaryotic cells Membrane bound nucleus Organelles Size differences Surface Area / Volume Ratio
Prokaryotes vs. Eukaryotes Differences: Eukaryotes have a nucleus and membrane bound organelles Genetic material transfer
Cell Membrane Separate the cell from its environment Lipid bilayer w/ proteins Attachment Movement of water & other bulk items Transport of molecules & ions Reception of chemical messages Passive transport Diffusion, Osmosis, Facilitative diffusion Active transport (pumps) Endocytosis Phagocytosis, pinocytosis
Endocytosis
Plant Cell Walls Cellulose Hemicelluloses Pectin Lignin Organic material Highest in high latititudes
Plant Cell Wall
Energy Transformations Growth, maintenance and replication 1 st & 2 nd Laws of Thermodynamic Photosynthesis Enzymes ATP (Adenine triphosphate)
Photosynthesis & Respiration 3 Bya: Capture photons and synthesize organic molecules 2 – 1.5 Bya: Release Oxygen Respiration Formula: 6CO 2 +12H 2 O + Light 6O 2 + C 6 H 12 O 6 + 6H 2 O Chlorophyll Chloroplast Inefficient
Photosynthesis
Enzymes
Materials of Life 97 % N, O, C, H 90 & H and O Water Macromolecules Carbohydrates Lipids Proteins Nucleic Acids
Water ¾ of the earth’s surface 2/3 of all organisms Three forms Polar molecule Universal solvent Adhesion – transport systems Stable against temperature changes – high heat of vaporization Most 4 o C
Carbohydrates Small molecules to long polymers Energy storage Sugars (CH 2 O) n Short term Monosaccharides Isomers Long Term Disaccharides & Polysaccharides Polysaccharide Glucose
Carbohydrates Structural Elements Polysaccharide cellulose Polysaccharide chitin Cellulases
Lipids Non-polar Many different kinds Fats Storage of energy Phospholipids Cell membrane Polar + non-polar groups : Lipid bilayer Terpenes Steroids
Proteins Various functions Fibres, enzymes, hormones, transport, ion-binding, toxins Chain of amino acid subunits (polypeptide) 20 amino acids
Nucleic Acids Information storage Deoxyribonucleic acid (DNA) & Ribonucleic acid (RNA) DNA Replicate itself Pass on hereditary material Nucleotides DNA structure Sugar-phosphate backbone Four bases
Nucleic Acids DNA structure
Nucleic Acids/DNA
Nucleic Acids RNA Read the DNA & produce proteins Structure Ribose Uracil instead of thymine
From DNA - Proteins
Genetic Code
The Diversity of Life At least 10 million species 1.5 million described
Levels of Organization Individual Unitary vs. Modular Population Defined area Community Physical feature of the habitat or dominant species Ecosystem Interaction between communities & their environment Material recycling
Species concept Species Morphological species concept identical by morphological (anatomical) criteria Biological species concept groups of potentially or actually interbreeding natural populations that are reproductively isolated from other such groups Isolating mechanisms Habitat, seasonal, behavioral, mechanical, gamete, hybrid failure Problems with fossil & asexual species Hybrid problem Evolutionary/Phylogenetic species concept All those individuals that share a common evolutionary history
Phylogenetic relationships
Evolutionary/Phylogenetic species
Classification & the Binomial System Linnaeus Felis catus Ranks
Ranks / Taxonomic Hierarchy Domain Kingdom Phylum Class Order Family Genus Species Eukarya Animalia Chordata Mammalia Carnivora Felidae Felis catus
Three Domains Bacteria Archaea Eukarya prokaryotes eukaryotes
Bacteria vs. Archaea Peptidoglycan layer
Six Kingdoms Eubacteria Archaeabacteria Animalia Plantae Fungi Protista prokaryotes eukaryotes
Six Kingdoms Eubacteria Archaeabacteria Animalia Plantae Fungi Protista Bacteria Archaea Eukarya
Protists Multicellularity evolved multiple times independently
Animalia Blastula Multicellular heterotrophs Tripoblasty Ectoderm Endoterm Mesoderm Movement Tube-within-tube Complex nervous systems
Plantae Photosynthesis Cell wall Sessile 350,000 species Land plants
Land Plants Nonvascular Vascular Gymnosperms Angiosperms
Fungi Heterotrophs Absorb their food Cell walls Spores Decomposition
Evolution of Kingdoms