BIOCHEMISTRY by linzhengnd


									                                      Biochemistry Notes
Chemistry – study of what substances are made of and how they change and combine.

          Each different kind of atom is a different element.
           Examples of elements: C – Carbon H – Hydrogen
                                    O – Oxygen N – Nitrogen
          Two or more elements combine to make a compound.
           Examples of compounds – H2O, CO2, HCl, NaCl
          Compounds are classified into 2 groups:
           1. Inorganic Compounds – come from nonliving substances (In = not Organic = living)

              Ex: H2O is the universal solvent because of its bent molecular shape and polarity.
                 Water dissolves other polar compounds by pulling them apart like a magnet separates
                                             Positive and
                                             ends like the
                                              poles of a

             *70-80% of your body is water

           2. Organic Compounds – come from living substances

Biochemistry – study of the chemistry of living organisms

            All organic compounds will have the element carbon in them
             Exception: CO2 is not organic (CO2 is not composed of living substances.)
            Organic compounds are usually complex compounds with many atoms in their structure.
             Ex: Glucose – C6H12O6
            Four kinds of organic compounds:
             1. Carbohydrates
             2. Proteins
             3. Lipids
             4. Nucleic acids (to be covered more in depth later) – DNA and RNA


Read the paragraph on pages 45- 46 of your text to complete the following diagram.

                                                                 • first and preferred energy
                                                                   source of cells
                                                 Function        • structural support in plants

                                                                 • monosaccharides – (one
                                                                   Ex: glucose, fructose
                                                                 • polysaccharides – (many
                                                Examples           Ex: starch ***
       Carbohydrates                                             • plant starch
                                                                   Ex: pasta, bread, rice
                                                                 • cellulose – gives plant cells
                                                                   rigidity and gives us fiber in
                                                                   our diet
                                                        • Ratio – 1C:2H:1O
                                                          Ex: Glucose – C6H12O6
                                      Compositon /      • How are large
                                        Structure         macromolecules formed?
                                                          Smaller sugars combine to
                                                          make larger molecules.

Note: ***Polysaccharides are composed of monosaccharides bonded together
         Polysaccharides must be first broken down to monosaccharides for cells to use as energy

Structural Formula of Monosaccharide:


Read the paragraph on pages 47- 48 in your text to complete the following diagram

                                                       • control rate of reactions
                                                       • form bones and muscles
                                    Function           • transport substances in and
                                                         out of cells
                                                       • fights disease

                                                           • food examples from animals –
                                                             eggs, milk, meat
                                      Examples             • food examples from plants –
      Proteins                        (not in the            nuts, beans
                                                           • enzymes

                                                    • elements involved – C, N, H, O
                                                    • proteins are composed of –
                                                      amino acids
                              Structure             • How many different amino
                                                      acids are there? 20

Structural Formula of Amino Acid:


Read the paragraph on pages 46-47 in your text to complete the following diagram.

                                                    • store energy – provides
                                                      more energy per gram
                                Function              than carbs
                                                    • part of cell membranes
                                                      and waterproof coverings

                                                          • fats
                                                          • oils
          Lipids                      Examples            • steroids
                                                          • waxes

                                                    • saturated – contains only
                                                      single bonds, solid at room
                                Diet info
                                                    • unsaturated – contains
                               (to be covered         double bonds, liquid at
                                   in class)          room temp. (Better for your

Structural Formula of Lipid:

                              Nucleic Acids

Read the paragraph on page 47 in your text to complete the following diagram

                                                    • store and transmit
                                      Function        genetic information
                                                      (parent to offspring)

          Nucleic Acids

                                                    • DNA
                                     Examples       • RNA

   Catalyst—substance that accelerates the rate of a chemical reaction
    Ex: hydrogen peroxide being broken down into water and oxygen

         H2O2        H2O    +   O2 add catalase for FASTER REACTION!

   Enzyme – a kind of catalyst found only in living things
   Enzymes are proteins
   Enzymes change only the speed of the reaction
   Enzymes are never used up in a reaction, so they can be used over and over
   Enzymes are specific for the reaction they catalyze
    Ex: Saltines and amylase

         Starch       Sugar

   Enzymes allow digestion to occur faster; otherwise the hamburger you ate last week might
    still be in your stomach!
   By using enzymes to break chemical bonds in food molecules, organisms release energy for
    life processes


To top