BSC 215 1st EditionLecture 2: Chemical Basis of LifeOutline of Last Lecture I. Major Themes of Anatomy and Physiology.II. Hierarchy of ComplexityIII. Know Organ Systems Figure A.11 in Atlas section in textbook. IV. Hierarchy of Complexity ContinuedV. Organ systems cooperate to maintain lifeVI. HomeostasisVII. Homeostasis Negative FeedbackVIII. Homeostasis Positive FeedbackIX. Key Anatomical TermsX. Body PlanesXI. Primary body cavitiesXII. Visualizing the bodyOutline of Current LectureI. Chemical Basis of LifeII. Law of conservation of energyIII. Atoms, Ions and MoleculesIV. Chemical BondsV. BiochemistryVI. AcidsVII. BasesVIII.PH ScaleIX. BuffersThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Current LectureI. Chemical Basis of Lifea. Matteri. Anything that occupies spaceb. Energyi. The capacity to do workc. Mass vs. weight is the difference in gravityd. Kinetic energyi. Movement of particles or objectse. Potential energyi. Stored energy that has the potential to do workf. Chemical energyi. Locked up in chemical bonds1. Most in our body2. When bonds break it is kinetic energyg. Electrical energyi. Movement of charged particles1. Ex. Nervous impulsesh. Mechanical energyi. Skeletal and muscular system1. Energy directly involved in moving matteri. Radianti. Energy that travels in wavesII. Law of conservation of energya. Energy can neither be created nor destroyedi. Stored energy is used for movementii. Taking chemical energy that is locked up and converting it to mechanical energy. iii. Ex. Jumping hurdlesIII. Atoms, Ions and Moleculesa. All matter is composed of elementsi. Elements1. A substance that cannot be broken down into simpler substances 2. 6 elements make up 98.5% of body massa. Oxygen 65%b. Carbon 18%c. Hydrogen 10%d. Nitrogen 3%e. Calcium 1.5%f. Phosphorous 1%b. All elements are composed of atomsi. Atom1. The smallest indivisible unit of mattera. Composed of protons, neutrons, and electronsb. Nucleus contains protons and neutronsc. Electrons orbit the nucleus2. Interactions between protons and electrons3. All atoms are electrically neutral4. Protons contribute to atomic mass5. Number of subatomic particles tells us what atom it isc. Properties of atomsi. Atomic number1. Number of protons in the nucleusii. Atomic mass1. Sum of protons and neutronsii. Isotopes1. Structural variants of the same elementa. Different number of neutrons= a different atomic massb. Have extra neutrons which break down and decayd. Radioactive Isotopesi. Heavy forms of isotopes are harmfulii. Harmful forms of radiation result from electron lossiii. Destroys moleculesiv. Alpha and beta have low penetration powerv. Radioactivity: dangerous- through skin and tissuesvi. Carcinogenic is cancer causing IV. Chemical Bondsa. Energy relationships between electrons of reacting atomsi. Shell one has 2 electrons max; other shells have 8 electrons maxb. Valence shelli. Outer most energy shellc. Ionic bondsi. Weakest bondsii. Transfer of electrons from one atom to another1. Electron donor becomes a positive cation2. Electron acceptor becomes a negative aniond. Non-polar covalent bondsi. Building a proteinii. Covalent=sharediii. Polar=same sort of directioniv. Non-polar= equal sharingv. Electrons are shared and each atom fills its outer electron shellvi. The idea is to work to share valence electrons by sharinge. Polar covalent bondsi. One has more power over anotherii. Atoms have different abilities to attract electronsiii. Ex. Oxygen is electronegative because it has 6 valence electronsf. Hydrogen bondsi. Not stable bondsii. Weak attractions between poles of water moleculesiii. Stabilization of biological moleculesiv. Forms waterv. DNA strands are held together by hydrogen bondsvi. Relies on molecules being polarvii. Break and form quicklyV. Biochemistrya. Studying the chemical composition of and reactions associated with living matteri. Inorganic1. Do not contain carbonii. Organic1. Contain carbonb. Inorganic Compoundsi. Water is the most abundant 1. Involved in putting together and breaking apart2. Water molecules surround with oxygen3. High heat capacitya. Absorbs and releases lots of heat before changing temperature4. High heat of vaporizationa. Liquid to gasb. Breakage of hydrogen bonds requires that a lot of heat is absorbedc. Absorb a lot of heat when changes. 5. Highly reactivea. Participates in hydrolysis reactions i. Breaking molecules by adding waterb. Participates in dehydration reactionsi. Making molecules by removing water6. Polar solventa. Polarity facilitates dissociation of ionic compounds7. H2O molecules interact with charges of ions and interaction with waterVI. Acidsa. Electrolytes that ionize and dissociate in water and can conduct electrical currents.i. Separatesii. Acidity is driven by concentration of hydrogen ionsiii. Stomach produces hydrochloric acidVII. Basesa. All are electrolytes and dissociate in water and can conduct electrical currentb. Proton acceptorsc. Dissociate into hydroxyl ionsVIII.PH Scalea. 7=neutralb. 1=acidicc. 13-14=basicd. blood is around neutralIV. Buffersa. works to maintain blood PHb. homeostasisc. blood typically gets more acidicd. waste products/breakdown of fat gives us acidityi. ex. Lactic acide. resist a change in PH f. Carbonic acid buffering system reaction is what keeps us alivei. Free hydrogen atoms that cause