Light microscope Be able to label: Stage Objectives Ocular Illuminator Iris diaphragm Course adjustment Knob Fine adjustment knob TEM IMAGE Redis experiment concluded: Maggots come from flies laying eggs not the rotted meat His research refuted spontaneous generation The Germ Theory Robert Koch Infectious diseases are caused by microorganisms or germs. Discovered bacillus responsible for TB Fig. 3-2 Hydrogen bond H + + H O + + + + + + Water molecules bond together by hydrogen bonds. This is called cohesion. The Solvent of Life A solution is a liquid that is a homogeneous mixture of substances A solvent is the dissolving agent of a solution The solute is the substance that is dissolved An aqueous solution is one in which water is the solvent Copyright 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fig. 3-7 Cl Na Cl Na + + Water is polar; a bent molecule with uneven partial charges. This makes it the universal solvent. Positively charged hydrogen is pulling on the neg. charged Cl of NaCl. This is how salt dissolves. Fig. 3-9 Neutral solution Acidic solution Basic solution OH H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Neutral [H + ] = [OH ] Increasingly Acidic [H + ] > [OH ] Increasingly Basic [H + ] < [OH ] pH Scale Battery acid Gastric juice, lemon juice Vinegar, beer, wine, cola Tomato juice Black coffee Rainwater Urine Saliva Pure water Human blood, tears Seawater 9 10 Milk of magnesia Household ammonia Household bleach Oven cleaner Buffers The internal pH of most living cells must remain close to pH 7 Buffers are substances that minimize changes in concentrations of H + and OH in a solution Most buffers consist of an acid-base pair that reversibly combines with H + Copyright 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fig. 5-5 (b) Dehydration reaction in the synthesis of sucrose GlucoseFructose Sucrose MaltoseGlucose (a) Dehydration reaction in the synthesis of maltose 14 glycosidic linkage 14 glycosidic linkage Fig Hydrophilic head Hydrophobic tail WATER Made of a phospholipid bilayer. Proteins can embed in this Membrane to serve various functions Fig Enzyme (sucrase) Substrate (sucrose) Fructose Glucose OH H O H2OH2O Diagram of an enzymatic reaction Fig. 5-UN1 Amino group Carboxyl group carbon An amino acid. It has 2 functional groups. Fig Nonpolar Glycine (Gly or G) Alanine (Ala or A) Valine (Val or V) Leucine (Leu or L) Isoleucine (Ile or I ) Methionine (Met or M) Phenylalanine (Phe or F) Trypotphan (Trp or W) Proline (Pro or P) Polar Serine (Ser or S) Threonine (Thr or T) Cysteine (Cys or C) Tyrosine (Tyr or Y) Asparagine (Asn or N) Glutamine (Gln or Q) Electrically charged AcidicBasic Aspartic acid (Asp or D) Glutamic acid (Glu or E) Lysine (Lys or K) Arginine (Arg or R) Histidine (His or H) There are 20 amino acids available for living organisms to make proteins.. Peptide bond Fig Amino end (N-terminus) Peptide bond Side chains Backbone Carboxyl end (C-terminus) (a) (b) Protein Structure and Function A functional protein consists of one or more polypeptides twisted, folded, and coiled into a unique shape Copyright 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings If a protein loses its shape, it loses it function. The protein would become Denatured. What Determines Protein Structure? In addition to primary structure, physical and chemical conditions can affect structure Alterations in pH, salt concentration, temperature, or other environmental factors can cause a protein to unravel This loss of a proteins native structure is called denaturation A denatured protein is biologically inactive Copyright 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Succession a change in Organisms (esp. plants) in a community over time. (a) Soon after fire(b) One year after fire What distinguishes primary succession from secondary? The ans: ESTABlSHED SOILS 2,000 1,500 1, Number of generations Population size (N) Exponential growth 1.0N = dN dt 1.0N = dN dt K = 1,500 Logistic growth 1,500 N 1,500 The # of organisms an environment can support J Curve S curve Snowshoe hare Lynx Number of lynx (thousands) Number of hares (thousands) Year Boom & Bust Indicates close predator/prey interaction Humans Smaller toothed whales Baleen whales Sperm whales Elephant seals Leopard seals Crab-eater seals Birds Fishes Squids Carnivorous plankton Copepods Euphausids (krill) Phyto- plankton Marine food web Showing connectedness of organisms using energy arrows ??? ??? Photosynthesis fill in the blanks Fig Primary producers 1000 J 1,000,000 J of sunlight 100 J 10,000 J 100,000J Primary consumers Secondary consumers Tertiary consumers Only 10% of energy Moves on to next trophic level Fig Lake trout 4.83 ppm Concentration of PCBs Herring gull eggs 124 ppm Smelt 1.04 ppm Phytoplankton ppm Zooplankton ppm Biological magnification The toxins at the bottom of the food web become more concentrated as they move up the food web. Fig c Decomposers N 2 in atmosphere Nitrification Nitrifying bacteria Nitrifying bacteria Denitrifying bacteria Assimilation NH 3 NH 4 NO 2 NO 3 + Ammonification Nitrogen-fixing soil bacteria Nitrogen-fixing bacteria A natural phenomenon Fig O2O2 Sunlight Cl 2 O 2 Chlorine Chlorine atom O3O3 O2O2 ClO Ozone depletion Competitive Exclusion Principle 1961 J.H. Connell University of California No 2 species can occupy the same niche at the same time Resource partitioning using different aspects of a resource Which resources in reducing competition. Discoveries since the Cell Theory Endosymbiotic Theory In 1970, American biologist, Lynn Margulis, provided evidence that some organelles within cells were at one time free living cells themselves Supporting evidence included organelles with their own DNA Chloroplast and Mitochondria 38 Endosymbiotic theory Prokaryotes Cell surrounded by cell membrane & cell wall Nucleoid region (center) contains the DNA Contain ribosomes (no membrane) in their cytoplasm to make proteins Flagella long tail like structure that aids in movement Eukaryotes More complex type of cells Cells Have a nucleus and membrane-bound organelles Includes single cell and multi cellular organisms like protists, fungi, plants, and animals 41 Nucleolus Nucleus Nuclear envelope Ribosome (attached) Ribosome (free) Cell Membrane Rough endoplasmic reticulum Golgi apparatus Mitochondrion Smooth endoplasmic reticulum Centrioles 42 Plant Cell Organelles The HardyWeinberg principle states: Both allele and genotype frequencies in a population remain constant or are in equilibrium from generation to generation unless Disturbing influences happen such as non- random mating, mutations, selection, limited population size, random genetic drift and gene flow. Genetic equilibrium is a basic principle of population genetics. The Hardy-Weinberg principle is like a Punnett square for populations, instead of individuals. Directional Selection The peppered moth p 2 + 2pq + q 2 = 1; p + q = 1 1. In nature there is a tendency towards ______________. 2. ___________ exists in any population 3. Not all organisms survive because of the ________________ 4. ___________ will survive and pass favorable variations to the next generation 5. In time, ___________ arise, until a new species evolves from an old species. Adaptive radiation ex. finches adapted to different environments on different islands Individuals from the mainland population A left. They inhabited an island and eventually evolved over time and became species B. The same kind of Thing happens to get species B, C, D, and E Coevolution Mutual evolutionary influence between two species Typically evolution of two species totally dependent on each other. Exert selective pressure on the other, so they evolve together. Extreme example of mutualism. A kind of evolution wherein organisms evolve structures that have similar (analogous) structures or functions in spite of their evolutionary ancestors being very dissimilar or unrelated.evolutionorganismsanalogous What is biological fitness???