Chapter 6: The Chemistry of Life

2 Everything is made up of Elements  Elements are made up of only one type of atom  96% of the atoms in the human body are either:  Carbon, Hydrogen, Oxygen or Nitrogen

3 Mixtures and Solutions  Mixture: A combination of substances in which each substance retains its chemical properties.  Ex. Sand and pepper.  Solution: A combination in which one substance is dissolved into the other.  Ex. Chocolate milk, ocean water

4 Solutions  Solute: The substance that is being dissolved.  Ex. Lemonade mix  Solvent: The substance that the solute is being dissolved into.  Ex. Water

5 Water  Possibly the most important substance for living things on Earth.  It is the ultimate solvent!  Water is a polar molecule.  It has both a pos. and neg. charge

6  Water is composed of Oxygen and Hydrogen (H 2 O)  The attraction between the atoms forms a Hydrogen bond  Hydrogen bonds help hold many large molecules together

7 Diffusion  Diffusion is the movement of particles from an area of high concentration to an area of low concentration.  Diffusion continues until there is no more concentration gradient.

8 The Role of Carbon in Organisms  Organic Compounds are large molecules, or macromolecules, that contain carbon (C).  Proteins, lipids, carbohydrates, and nucleic acids.

9  Carbon atoms can form a single, double, or triple covalent bond with one another (C-C, C=C, or C  C)  Polymer: A macromolecule composed of many smaller molecules or units, usually chained together.

10 Carbohydrates  Carbohydrate: A molecule composed of carbon, oxygen and hydrogen, with a ratio of 2 hydrogen atoms and one oxygen atom for each carbon atom.  Ex. Glucose C 6 H 12 O 6

11  Isomer: Compounds that have the same formula but different 3 dimensional configurations.  Ex. Glucose and fructose.

12 Carbohydrates  The simplest type of carb. Is called a monosaccharide.  If you broke down a monosaccharide any further, you would no longer have a sugar.

13  Condensation/dehydration reaction: When 2 or more monosaccharides combine to form a disaccharide or a polysaccharide.

14 Carbohydrates  Disaccharide: A sugar molecule created when two and only two simple sugars (monosaccharides) combine.  Ex. Sucrose (table sugar). hem/255chemistry.htm

15  Polysaccharide: A sugar molecule created when more than two simple sugars (monosaccharides) combine.  Ex. Starch, glycogen, cellulose.

16 Carbohydrates Starch: used as food storage in plants.

17 Carbohydrates Glycogen: Food storage molecule for mammals. Similar to starch but more highly branched.

18 Carbohydrates Cellulose: Forms plant cell walls, used for support. Glucose subunits hooked together like a chain-linked fence.

19 Lipids  Lipids: organic compounds that have much less oxygen than carbs.!

20  Referred to as fats and oils  Ex. Beef fat: C 57 H 110 O 6  Insoluble in water because they are non-polar  Used by cells for energy storage, insulation and a protective coating.  A major component of membranes that surround all living cells is glycerol  The backbone for the lipid molecule

21 Types of Fats  Saturated Fats: No double bonds (all single bonds) between the carbons of the fatty acid chain.  Ex. Steak fat, butter fat, usually solid.

22  Unsaturated Fats: Contain double bonds between the carbons of the fatty acid chain.  Ex. Vegetable oil, peanut fat, usually liquid.

23 Saturated V/S Unsaturated Fats

24  Saturated fats are the very unhealthy fats.  They make the body produce more cholesterol, which may raise blood cholesterol levels.

25 Proteins  A protein is a large, complex polymer  composed of C, H, O, N, and sometimes S atoms.

26 Amino Acids  Amino Acids are the building blocks of proteins.  There are 20 amino acids found in nature.  Their order determines the type of protein.  They become linked due to a condensation rxn.

27  Peptide Bond: The covalent bond found between two amino acids.

28 The Importance of Proteins  They have important functions in all living things.  Form Teeth, Hair, Fingernails, Exoskeletons.  Carry O 2 in blood, help provide immunity, etc.

29 The Structure of Nucleic Acids  Nucleic Acid: A complex macromolecule that stores cellular info. in the form of a code.  Made up of smaller subunits layered one on top of the other called nucleotides.

30  Nucleotides are comprised of a simple sugar, a phosphate group, and a nitrogen base.  C, H, O, N, P atoms all present.  Can contain the information necessary to synthesize proteins.

31 Nucleotide Structure

32 DNA: type of nucleic acid  DNA: DeoxyriboNucleic Acid.  A master copy of an organism’s genetic information  Double helix: p  Strands of DNA form genes, which are the components of chomosomes.

33 RNA: type of nucleic acid  RiboNucleic Acid  Helps in the formation of DNA and many proteins. Not a double helix.

34 Chemical Reactions  Chemical reactions involve the breaking of bonds in reactants and the formation of new bonds in products  Example: 2H 2 + O 2 2H 2 O

35 Energy in Reactions  Chemical reactions that release energy occur spontaneously  Example: Hydrogen gas burning.

36 Energy in Reactions  Chemical rxns that absorb energy will not occur without a source of energy  Example: must add energy to force water to decompose into hydrogen and oxygen

37 Enzyme (Ernie)  A protein that acts as a biological catalyst  Catalyst: a substance that speeds up the rate of a chemical reaction  enzymes work by lowering the activation energies of chemical reactions enzymes

38 Lowering Activation Energy Less energy is needed to complete the reaction. Result: the reaction occurs faster!

39 Enzymes  Only work on specific substrate (specificity)  Are not used up in chemical reactions ~ can be used again.  zyme%20activity.html zyme%20activity.html

40 Enzymes  Can be denatured with heat or pH and will no longer work.

41 Important Study Tips  Elements/Compounds/Molecules  Nucleus/Protons/Neutrons/Electrons  Energy Levels/Electron Clouds  Isotope/Isomer/Ion  Ionic/Covalent Bond  Mixture/Solution  Solvent/Solute  Acid/Base/pH  Diffusion/Kinetic Energy/Brownian Motion  Polymers – Carbohydrates/Lipids/Proteins/Nucleic Acids  Saturated/Unsaturated Fats  Amino Acids/Peptide Bonds  Proteins/Enzymes  DNA/RNA/Nucleotides

42 Section 6.1 Vocabulary Element Compounds Proton Ion Ionic Bond Metabolism Product Reactant Subscript Chemical Equation Molecule Covalent Bond Isotope Atom Trace Element Energy Levels Electron Neutron Nucleus

43 Section 6.2 Vocabulary Mixture Dynamic Equilibrium Diffusion Concentration Gradient Kinetic Energy Brownian Motion Robert Brown Hydrogen Bond Polar Molecule Importance of Water pH OH- Base H+ Acid Solvent Solute Solution List 3 factors that affect diffusion

44 Section 6.3 Vocabulary PolymerIsomers Condensation Hydrolysis Glycerol Proteins Lipids Amino Acids Carbohydrate Monosaccharide Disaccharide Polysaccharide Nucleic Acid Peptide Bond Enzymes Substrate Active Site Nucleotide DNA RNA