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Chapter 2

Chapter 2. Chemistry of Life. 2.1 The nature of matter. Key questions What are the three atomic particles that make up an atom? How are all of the isotopes of an element similar? In what ways do compound differ from their compound elements? What are the main types of chemical bonds VOCAB:

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Chapter 2

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  1. Chapter 2 Chemistry of Life

  2. 2.1 The nature of matter • Key questions • What are the three atomic particles that make up an atom? • How are all of the isotopes of an element similar? • In what ways do compound differ from their compound elements? • What are the main types of chemical bonds VOCAB: • atom • Nuclues • Electron • Element • Isotope compound • Ionic bond • Ion • Covalent bond • Molecule • Vandderwaals Forces

  3. Atoms • Democritus: 2500 years ago • What happens when you break a piece of chalk? • Atom: Atomos “unable to cut” • Parts of an atom: • Protons: • positive charge • Clumped in nucleus • Neutrons: No charge • Clumped in nucleus • Same mass as protons • Electrons: Negative charge • Much smaller then proton/neutron • 1/1840 the mass • Constantly moving around positive core **Same amount of protons and electrons = a Neutral charged atom!

  4. Carbon atom

  5. Nature of matter continued… • Elements vs isotopes: • Element: • Pure substance that consists of entirely one atom • Over 100 elements are known • 2 dozen are commonly found in living organisms • Represented on the periodic table • www.ptable.com/ • Isotopes: • Atoms of the same element that differ in the number of neutrons • Protons + neutrons = MASS NUMBER • Example: carbon 12, 13, 14 • Because they have the same number of electrons, all isotopes of an element have the same chemical property • Radioactive: their nuclei are unstable and breakdown at a constant rate over time

  6. 2.1 continued… • Chemical compound: • Substance formed by the chemical combination of two or more elements in definite proportions • Examples: h20, NaCl • Chemical bonds • Ionic: • One or more electrons are transferred from one atom to another • This creates a positive and negative atom therefore an attraction • Covalent • Electons travel between each atoms nucleus • http://www.youtube.com/watch?v=xTx_DWboEVs • Van derwaal forces • Attractions bewteen covalent bonding • www.visionlearning.com/library/...1/CHE1.7-bonding.htm

  7. 2.2 Properties of water • Key questions • How does the structure of water contribute to its unique properties • How does water’s polarity influence its properties as a solvent • Why is it important for cells to buffer solutions against rapid changes in PH • Vocab: • Hydrogen bond • Cohesion • Adhesion • Mixture solution • solute • Solvent • Suspension • PH scale • Acid • Base • buffer

  8. 2.2 water • Covalent bond/ neutral charge: 10+ 10- • Polarity: • because of the covalent bond….h2o has a unique shape • There is a + and – pole within the molecule. • This polarity encourages Hydrogen bonding • Hydrogen bond: • The polarity of the hydrogen and oxygen attract each other similar to a covalent bond

  9. Hydrogen bonding

  10. Water conintued… • Cohesion • Attraction between molecules of the same substance • To be drawn together • Examples: beading and surface tension • Adhesion • Attraction of molecules of different substance • Examples: water in a cylinder • Heat capacity • Tolerant of heat • High heat capacity • Protects the organisms within. Why?

  11. Mixture • A material composed of two or more elements or compounds that are physically together no chemically combined. EX: salt and pepper • Solutions: • all components of a solution are evenly distribute by a polar bond • Solute: substance that is being disolved • Solvent: doing the dissolving • Suspensions: • No dissolving • Separate into pieces so small that they do not settle out. • Example: blood, dressing

  12. Acids, bases, and PH Water molecules often split to form ions. (hydrogen and hydroxide ions) • pH scale • scale made to indicate the level of these H+ ions in the solution. • Ranges from 0-14 • 0 = acid, 7 = pure • Each step on the ladder is a matter of “10”

  13. pH scale and environmental effects

  14. Acids, bases, and buffers continued… • Acids • pH below 7 • Higher concentration of H+ • Strong acids at 1-3 • Bases • pH above 7 • Lower concentrations of H+ • Strong bases 11-14 (lye=soap) • Buffers • Ph levels in body must be kept within 6.5-7.5 buffers are weak acids /bases that help control the drastic change.

  15. Review 2.2 • Key questions • How does the structure of water contribute to its unique properties • How does water’s polarity influence its properties as a solvent • Why is it important for cells to buffer solutions against rapid changes in PH • Vocab: • Hydrogen bond • Cohesion • Adhesion • Mixture solution • solute • Solvent • Suspension • PH scale • Acid • Base • buffer

  16. 2.3 Carbon compound • Key questions • What elements does carbon bond with to make up life’s molecule? • What are the functions of each of the four groups of macromolecules • Vocab • Monomer • Polymer • Carbohydrate • Monosaccharide • Lipid • Nucleic acid • Nucleotide • Protein • Amino acid

  17. Why is carbon so Cool? • 4 valence electrons to form strong covalent bonds • Carbon can bond with many elements for ‘life” • Hydrogen • Oxygen • Phosphorus • Sulfur • nitrogen • Bond to itself • Can from single, double, or triple covalent bonds • Can be unlimited in length • Can even circle onto itself • Most versatile of elements

  18. Macromolecules • Macromolecules: made up thousands/hundreds of thousands of smaller molecules • Formed by Polymerization: when large compounds are built by joining smaller ones: monomers and polymers • monomers: single • Polymers: many parts

  19. Four types of macromolecules for life • Carbohydrates • Carbon/ hydrogen / oxygen (1:2:1 ratio) • Breaking of these bonds are the primary source of energy • Sugars • Simple sugars (monosaccharides) • Single sugar molecules • Ex: glucose, galactose and fructose • Complex carbohydrates • polysaccharides

  20. Lipids • Mainly carbon and hydrogen • Not water soluble • Common categories • Fats • Oils • waxes • Can be energy but commonly as membrane coverings • when a glycerol is combined with fatty acid • Saturated: if each carbon is connect by single bond to another carbon • Unsaturated: at least one double carbon-carbon bond • Poly-unsaturated: more than one double carbon bond

  21. Nucleic acids • Macromolecules formed from H,O, N, C and phosphorous • Assembled from polymers known as nucleotides • Nucleotides: 3 parts example (ATP) • 5 carbon sugar • Phosphate group • Nitrogen base • Nucleic acids store and transmit heredity and genetic information • Examples: DNA RNA

  22. Proteins • Made from polymers AMINO ACIDS • Covalent bonds called peptide bonds • Some control rate of cell reaction • Some form cell structures • Aid in transport • Many of chains of peptides • Structure • 20 different types • Bonding sites are the same • Organizations • Peptide chains

  23. 2.3 review • Key questions • How does the structure of water contribute to its unique properties • How does water’s polarity influence its properties as a solvent • Why is it important for cells to buffer solutions against rapid changes in PH • Vocab: • Hydrogen bond • Cohesion • Adhesion • Mixture solution • solute • Solvent • Suspension • PH scale • Acid • Base • buffer

  24. 2.4 chemical reactions and enzymes • Key questions • What happens to chemical bonds during chemical reactions • How do energy chances affect whether a chemical reaction will occur • What role do enzymes play in living things and what affects their function • Vocab • Chemical reaction • Reactant • Product activation energy • Catalyst • Enzyme • substrate

  25. Chemical reactions What is a chemical reaction? • Process of changing or transforming one set of chemicals into another. • Involve changes in the chemical bonds that join atoms in compounds SO……that means? • **MASS AND ENERGY ARE CONSERVED DURING CHEMICAL REACTION** • Reactants: chemicals that go into the reaction • Products: chemical/compound resulting from the reaction • Example : pg. 50 blood stream/co2

  26. Energy in reactions Energy is released or absorbed chemical bonds are broken or broken • Releasing energy can happen on their own/spontaneously • Example: burning hydrogen gas • 2h2 + O22H2O • Energy is released in the form of heat! • Absorbing energy needs an energy source • Example: returning h2o to hydrogen and O2 gases • So much energy needed that it can’t happen on its own • Energy sources: • Activiation energy: Energy needed to start a chemical reaction

  27. Enzymes • Proteins that act as a biological catalyst • Catalyst: substance that speeds up chemical reaction • Example blood stream and carbonic anhydrase and its effect on co2 and h20 • Lock and key (substrates) • regulation

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