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