AP Biology- Biochemistry 1 Mrs. Stahl A Chemical Connection to Biology _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Example- Some ant species use formic acid to protect themselves against predators and microbial parasites. o “When a crazy ant is smeared with the venom in a fight with a fire ant, it secretes formic acid from its abdominal glands, transfers it to its mouth and then spreads it on its body - a practice that makes crazy ants almost invincible in combat with fire ants over resources such as food and nesting sites. In lab experiments, the crazy ants that were allowed to detoxify themselves had a 98 percent survival rate, according to the study, published in the journal Science Express.” http://www.ibtimes.com/crazy-ants-useformic-acid-wash-fire-ant-venom-becoming-dominant-invasive-species-us-southeast The Nature of Atoms Matter- ______________________________________________________ Atom-________________________________________________________ 1913- Niels Bohr and The Atomic Theory o Protons-__________________________ o Neutrons-__________________________ o Electrons-__________________________ o Nucleus-_________________________________________________ o Electron Cloud-___________________________________________ AP Biology- Biochemistry 2 Mrs. Stahl Elements and Compounds Matter is made up of elements. Element: _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Compound:____________________________________________________ ____________________________________________________________ The Elements of Life _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Trace Elements: _____________________________________________________________ _____________________________________________________________ An element’s properties depend on the structure of its atoms _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Subatomic Particles _____________________________________________________________ Relevant subatomic particles include: o Neutrons- no electrical charge o Protons- positive charge o Electrons- negative charge Neutrons and protons for the _______________________________ AP Biology- Biochemistry 3 Mrs. Stahl _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Label according to the picture. Atomic Number and Atomic Mass Atoms of the various elements differ in number of subatomic particles. _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ AP Biology- Biochemistry 4 Mrs. Stahl Isotopes All atoms of an element have the same number of protons but may differ in number of neutrons. Isotopes_____________________________________________________________ _____________________________________________________________ Radioactive isotopes_____________________________________________________________ _____________________________________________________________ Radioactive Tracers • Radioactive isotopes are often used as diagnostic tools in medicine • Radioactive tracers can be used to track atoms through metabolism • They can also be used in combination with sophisticated imaging instruments Radiometric Dating _____________________________________________________________ _____________________________________________________________ In radiometric dating, scientists measure the ratio of different isotopes and calculate how many half-lives have passed since the fossil or rock was formed. _____________________________________________________________ _____________________________________________________________ o Example- Carbon dating of fossils ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ Allows scientists to pinpoint when materials formed. AP Biology- Biochemistry 5 Mrs. Stahl The Energy Levels of Electrons Energy_____________________________________________________________ _____________________________________________________________ Potential Energy_____________________________________________________________ _____________________________________________________________ o Example- grapefruit: If you hold a grapefruit in your hand, above the ground= posses potential energy. If you drop the grapefruit and it falls, PE decreases. Carry it to the top of a building, PE increases. _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Each level corresponds with a specific amount of energy Every atom has a ladder of potential energy values _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ AP Biology- Biochemistry 6 Mrs. Stahl Fill it in according to the diagram on the slide. Electron Distribution and Chemical Properties _____________________________________________________________ _____________________________________________________________ We cannot pinpoint the location of any given electron at any time. Electron could be anywhere. AP Biology- Biochemistry 7 Mrs. Stahl Orbital_____________________________________________________________ _____________________________________________________________ The periodic table of the elements shows the electron distribution for each element. Oxidation_____________________________________________________________ _____________________________________________________________ Reduction-____________________________________________________ Valence Electrons_____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ How does oxidation / reduction help organisms? _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Chemical Bonds Molecule_____________________________________________________________ _____________________________________________________________ Compound- molecule of more than one element. AP Biology- Biochemistry 8 Mrs. Stahl Chemical bonds_____________________________________________________________ _____________________________________________________________ Bonds and Interactions Name Covalent Bond Basis of Interactions Strength Strongest Bond Ionic Bond Hydrogen Bond Hydrophobic Interaction Van der Waals forces Weakest AP Biology- Biochemistry 9 Mrs. Stahl The Molecule that Supports all of Life _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ The structure of the water molecule allows it to interact with other molecules and this was true in the beginning when other molecules would around and interact. Water’s unique emergent properties help make Earth suitable for life. Life began in the water for two billion years before moving onto land. _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ What is the difference between a tropical rainforest biome and a desert biome? _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Polar covalent bonds in water molecules result in hydrogen bonding In the water molecule, the electrons of the polar covalent bonds spend more time near the oxygen than the hydrogen. AP Biology- Biochemistry 10 Mrs. Stahl _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Draw and Label the diagram of the water molecule: AP Biology- Biochemistry 11 Mrs. Stahl Hydrogen Bonds: _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Water is the Universal Solvent: _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Aqueous Solution: one in which water is the solvent. Example: Kool-aid, sugar, and water o Solvent= water o Solutes= sugar and Kool-aid o Solution= all mixed together and the distribution is even throughout Other terms to know: Hydrophilic:_______________________________________________________ __________________________________________________________________ Example: ____________________________________________________ AP Biology- Biochemistry 12 Mrs. Stahl Hydrophobic: __________________________________________________________________ __________________________________________________________________ Example:_____________________________________________________ Hydrophobic Exclusion: _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ This can affect the structure of proteins, DNA, and biological membranes. Critical to living systems Amphipathic _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Properties of Water • Cohesion and Surface Tension • Adhesion and Capillary Action • High Specific Heat • High Heat of Vaporization • Low Density of Ice AP Biology- Biochemistry 13 Mrs. Stahl Cohesion: _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Surface Tension: _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Adhesion: _____________________________________________________________ _____________________________________________________________ o Example: ________________________________________________________ ________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ o Example: ________________________________________________________ ________________________________________________________ Heat • Kinetic Energy = energy of motion • Heat= total amount of energy in a system • Temperature= measure of the average kinetic energy of molecules • Calorie= the amount of heat needed to raise the temperature of water by 1 C AP Biology- Biochemistry 14 Mrs. Stahl High Specific Heat _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Defined as: the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C The specific heat of water is 1 cal/g/°C _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ o Heat is absorbed when hydrogen bonds break o Heat is released when hydrogen bonds form Why do organisms have a high water content? To maintain a constant internal temperature _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Heat of Evaporation _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Heat of vaporization is the heat a liquid must absorb for 1 g to be converted to gas _____________________________________________________________ _____________________________________________________________ AP Biology- Biochemistry 15 Mrs. Stahl _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Density of Ice _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ AP Biology- Biochemistry 16 Mrs. Stahl Solute Concentrations in an Aqueous Solution • Most chemical reactions in organisms involve solutes dissolved in water • When carrying out experiments, we use mass to calculate the number of solute molecules in an aqueous solution • Molecular mass is the sum of all masses of all atoms in a molecule • Numbers of molecules are usually measured in moles, where 1 mole (mol) = 6.02 1023 molecules • Avogadro’s number and the unit dalton were defined such that 6.02 1023 daltons = 1 g • Molarity (M) is the number of moles of solute per liter of solution Water Can Form Ions • _____________________________________________________________ • 1 out of every 550 million water molecules spontaneously break • _____________________________________________________________ • H2O -> OH- + H+ • For some reason a proton, from the hydrogen's nucleus dissociates from the molecule of water. • Dissociation= _____________________________________________________________ _____________________________________________________________ AP Biology- Biochemistry 17 Mrs. Stahl Explanation of Dissociation: Copy the board AP Biology- Biochemistry 18 Mrs. Stahl