LIVING THINGS EVOLUTION Biology 1101 Why do some organisms seem suited for their environment o o Ex Hummingbird long beak for nectar in certain flowers Ex Cheetahs take down faster prey Adaptation inherited characteristic that enables an organism to successfully survive reproduce Evolution change in the genetic makeup of a population over time Population group of individuals of the same species All living things come from other living things Ex One single celled organism to another DNA is copied passed to offspring The signature molecule of life Ex embryo cells continually divide develop o o o Individuals with the best adaptations to current environment Natural selection is one mechanism of evolution Organized in a specific way Need Acquire energy 1 2 3 Maintain internal constancy homeostasis Sample size Variables o o o Independent manipulated variable Dependent response variable Standardize variable Control group DIFFERENCE BETWEEN HYPOTHESIS AND THEORY Hypothesis DESIGN A CONTROLLED EXPERIMENT SCIENTIFIC METHOD 4 5 Reproduce grow develop Evolve Observation Frame question that relates Prediction Design conduct experiment Collect data Draw conclusion Submit for publication Preliminary question If then statement Can incorporate laws Tentative often narrow explanation regarding the natural world Must be testable falsifiable Theory Unifying explanation Diverse lines of evidence A well substantiated explanation of some aspect of the natural world Broad ties together existing observations Ideas about which we are most certain ex orange falls to ground CHEMISTRY OF LIFE Elements Pure substances that can t be broken down by chemical means ex Ca O Ba Atom Smallest component of an element protons neutrons electrons Chemical Bonds link atoms Atoms bond through chemical bonds forces of attraction that hold atoms together Molecule 2 or more chemically bonded atoms ex H2O Electrons move around nucleus in energy shells Octet rule atoms ions are most stable when they have 8e in outer valence shell 1 BASIS OF ALL CHEMICAL RECTIONS Biology 1101 If octet rule is not satisfied atoms will lose gain or share to fill valence If stable then it will not react Electro negativity Ability to attract electrons Covalent bond Sharing bong Non polar covalent bond share electrons equally Polar covalent bond non equal sharing Ionic bond Stealing bond If electro negativity is great enough one will take an e from another Results from electrical attraction between 2 oppositely charged ions o o o o Hydrogen Bonds bonds of attraction o Weak force of attraction WATER PROPERTIES OF WATER Hydrogen bonds result in a property of water called cohesion water molecules stick together Results in high surface tension Constantly forming and breaking Polar substances dissolve in water ex NaCl in water Molecules of water surround each ion and separate them from one another Substances that dissolve in water are hydrophilic Substances that do not dissolve in water are hydrophobic Ice floats o When the temperature drops water molecules slow down and keep their H bonds longer o o Locks into a crystalline lattice with its neighbors Less molecules in a given space the density is now lower o o o ORGANIC MOLECULES Organic Molecules are compounds containing both carbon and hydrogen Carbon has four vacancies Many are macromolecules polymers chains created by linking subunits called monomers FOUR MAIN TYPES Carbohydrates Simplest of the main organic molecules Structural molecules Simple sugars monomers Disaccharides complex carbs forms by the union of 2 simple sugars Polysaccharides complex carbs for by the union of many simple sugars o Complex cabs polymer Lipids o o All are insoluble in water hydrophobic Rich in energy good for long term E storage Source of energy the carbon hydrogen bond store a great deal of energy and are easily broken Glucose blood sugar molecular bonds are broken down by your cells and release energy If you do not use this energy your body stores it and converts into fat long term monomer Glycogen short term polymer Cellulose Is a glucose molecule found in plants dietary fiber digestive benefits 2 o o Lots of C H bonds Fats largest part of the cell membrane Biology 1101 Ex Triglyceride polymer of a lipid 3 fatty acid tails Fatty acids are saturated with hydrogen Degree of Saturation measure if fatty acid s H content Saturated Fat each carbon in the hydrocarbon chain is bond to 2 hydrogen atoms solid at room temperature animal derived butter cheeses Double bond site of unsaturation sharing an electron among each other Unsaturated Fat at least one carbon in the hydrocarbon chain is bounded to just one hydrogen double bond kinks in the chain liquid at room temperature tend to be plant derived olive oil can be found in fish Hydrogenation is the artificial addition of hydrogen atoms to an unsaturated fat This can improve a food s taste and shelf life not good for your health PROTEINS More functions than any other type of molecule 1 2 3 The most diverse more functions in the cell than any other type of molecule Structured Fold in a 3 D unique shape inside a cell Overall shape determines its function o o If the shape of the protein is modified enough to destroy its function it has denatured Protein polymer Amino acid monomer NUCLEIC ACIDS Stores and transmits genetic information DNA Deoxyribonucleic acid sugarsandphosphatesformthe rails and nitrogenousbasesformthe rungs RNA Ribonucleic acid Nucleotides the monomers of nucleic acids each nucleotide consists of a 5 C sugar a phosphate group and a nitrogenous base CELLS Cell theory Common Characteristic Cell membrane as a boundary DNA is genetic material RNA for proton synthesis all organisms consist of one or more cells the smallest unit of life that can function on its own all cells arise from other cells Ribosomes for protein manufacture Cytoplasm Cell membrane A very thin layer separates cytoplasm from exterior environment regulates what passes in and out of the cell helps maintain homeostasis Structure phospholipid bilayer Phospholipids and proteins move laterally within the bilayer 3 Biology 1101 Cells are small by necessity exchange nutrients and wastes thru membrane large SA V meets the cell s needs can be larger based on organelles TWO MAJOR CATAGORIES OF CELLS no membrane bound organelles no nucleus like an open warehouse o distinct spaces for different tasks but not separated by barriers Prokaryotes simple structures small Eukaryotes complex structure large have