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The Chemistry of Life

The Chemistry of Life. Elements. Substance that can’t be broken down into simpler chemical substances Made of atoms Smallest particle of an element that retains the characteristics of that element 25 Essential 4 make up 96% of organismal mass. Atomic Structure. Nucleus Protons

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The Chemistry of Life

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  1. The Chemistry of Life

  2. Elements • Substance that can’t be broken down into simpler chemical substances • Made of atoms • Smallest particle of an element that retains the characteristics of that element • 25 Essential • 4 make up 96% of organismal mass

  3. Atomic Structure • Nucleus • Protons • Positive charge • # determines chemical properties • Neutrons • No charge • Electron Cloud • Energy levels • Electrons (negatively charged)

  4. Atomic Structure Cont’d • Ions • Charged elements • Cation • Anion • Isotopes • Atoms of the same element that have different numbers of neutrons • radioactivity

  5. Compounds • Substance that is composed of atoms of two or more different elements that are chemically combined • Properties are different • Formed using BONDS

  6. Bonding • Covalent Bonds • Equal sharing of electrons • Strongest bond • 2 or more NONMETALS • Sugars, fats, proteins, water, etc.

  7. Ionic Bonds • Formed between a metal and a non-metal • Not as strong as covalent • Attraction of charge – IONS • Occurs through theft 

  8. Chemical Reactions • Breaking or formation of bonds • Metabolism – all the chemical reactions that occur within an organism • Greek: Metabole (to change) • What is our definition of energy???

  9. Mixtures and Solutions • Mixture: combination of substances in which the individual components retain their own properties • Solution: mixture in which one or more substances are distributed evenly in another substance • Solute and Solvent • Concentration

  10. Acids and Bases • pH – measure of acidity or basicity • Acid: forms H+ ions in solution • pH below 7 • Base: Forms OH- ions in solution • pH above 7 • Neutral: no ion formation • pH of 7

  11. Water • EXTREMELY IMPORTANT • Makes up 70-95% of organisms • Allows life processes to occur • Transport materials

  12. Properties of Water • Polar • Attract ions and polar molecules • “universal solvent” • Hydrogen Bonds • Hold biomolecules together! • Capillary Action and Surface Tension • Resists changes in Temperature (insulator) • Expansion upon freezing

  13. Diffusion • Kinetic Energy and Brownian Motion • Random, net movement of solute particles from an area of higher concentration to an area of lower concentration • Selectively Permeable Membrane as mediator • 3 Key Factors • Concentration • Temperature • pressure

  14. Diffusion Cont’d • Ultimate goal: Dynamic Equilibrium • Continuous movement of particles but no net change in concentration • Eliminates the concentration gradient • How might this differ from osmosis???

  15. The Role of Carbon • 4 covalent bonds…AT THE SAME TIME!!! • Straight chains • Branched chains • Rings • Isomers: compounds that have the same chemical formula but different three-dimensional structures • Biomolecules – large CARBON CONTAINING organic molecules

  16. The Role of Carbon Cont’d • Forms Polymers – chain of small molecules • Carbohydrates: CH20 • Simple sugars • Monosaccharides • Disaccharides • Polysaccharides • Broken down for Energy • Lipids: CH2 • Fats, oils, waxes, steroids • Insoluble in water

  17. Cont’d • Lipids • Fatty Acids • Saturated • Mono-unsaturated • Poly-unsaturated • Selectively Permeable Membrane • Polar, hydrophyllic head • Non-polar, hydrophobic tail

  18. Cont’d • Proteins • Large, complex polymer composed of C, H, O, N (and sometimes S) • Held together by peptide bonds • Carboxyl group and Amino group • Made up of Amino Acids (20 common) • Enzymes!!

  19. Cont’d • Nucleic Acids • Complex biomolecule that stores cellular information in the form of a code • Made of nucleotides • DNA/RNA • A, T, C, G

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