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BIOCHEMISTRY

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BIOCHEMISTRY Powered By Docstoc
					     What Makes up Living Things?
• What makes up Water?
• What makes up Carbon Dioxide, Oxygen, etc.
                    Elements
• Substances that are made up of only one type
  of atom.
• ex. Gold (Symbol: Au) Silver (Ag) Sodium (Na) -
  are types of metals
  Oxygen (O), Hydrogen (H), Helium (He),
  carbon (C) , Chlorine (Cl) Silicon (Si), Sulfur (S)-
  are types of non-metals
                Compounds
• substances made up of two or more elements
  combined in specific amounts.
• ex: Sodium Chloride-NaCl (formula for table
  salt)
  – one atom of sodium for every one atom of
    chlorine
• ex: Dihydrogen Oxide-H2O (formula for water)
  – two hydrogen atoms for every one oxygen atom.
• The cell is a complex "Chemical Factory" made up of
  the same elements that show up over and over again
  in different ways.
• Of all the elements found on earth, there are four
  main elements that are present in the greatest
  percentages (amounts) in living things. They are
•   C- carbon
•   H- hydrogen
•   O- oxygen
•   N- nitrogen
• There are other elements that are also found
  in living things, but in much smaller quantities.
  These are:
• S-sulfur, I-Iodine, Na-sodium, Fe-iron, Ca-
  calcium, K-potassium,
• Cl-chlorine, P-phosphorus Mg-magnesium

• ALL organisms are made up of Inorganic and
  Organic compounds
             I. Inorganic Compounds
   * compounds that do not contain both carbon and
   hydrogen.
   * organisms do require certain inorganic substances to
   survive:
A. Water (H2O)
   * 65% of most living tissues is H2O!!!
   * many substances in living things are dissolved in water
   (solution)
   * water acts as a transport agent to move substances
   across cell membranes.
B. Salts (ex: NaCl- sodium chloride)
   * provide many necessary ions for body processes.
   * help to regulate certain body processes.
C. Acids & Bases
   * help to regulate certain body processes
                     Water
• What’s so special about water?
  – It’s a great solvent
  – It hold’s tons of heat
  – It has high surface tension
  – Its less dense as a solid than a liquid
                pH Matters
• pH is a measure of hydrogen ion or H+ conc.
• Low pH = Acid (lots of H+s), High pH = Base
  (few H+s).
• In biology, keeping H+ levels within a narrow
  range is critically important
pH Scale
      Monomers and Polymers
• Monomers = repeated small units
• Polymers = Long molecules built by
  linking chain of repeating smaller units
           II. Organic Compounds
* compounds that contain both carbon
  and hydrogen
* mainly found in living things
A. Carbohydrates
B. Lipids
C. Proteins
D. Nucleic Acids
            A. Carbohydrates
* contain C, H, and O
ex. glucose-C6H12O6
* most end in -ose
* are the main source of energy for respiration
* also make up some parts of cells
       Structure of a Carbohydrate
• * the simplest carbohydrates are called
  monosaccharides
• (mono=one) (saccharides=sugars)
• Each subunit looks like this:


          Like a six -sided ring!



                                     Glucose
• What would two rings be called? What about
  many rings?
• TWO RINGS=a disaccharide (di= two)
  ex. maltose
• MANY RINGS= a polysaccharide (poly=many)
  ex. starch, glycogen
Carbohydrates
Carbohydrates
                    B. Proteins:
* contains C, H, O, and N
* sometimes contains S
* many different jobs:
  1. structural parts- proteins make up parts of the cell
     membrane, as well as body parts like muscles and hair
  2. enzymes- a class of proteins that control chemical
     reaction
  3. hormones- chemical messengers that regulate body
     functions
  4. antibodies- protect the body against disease
  5. pigments- molecules of color-hemoglobin, melanin,
     chlorophyll
• You can find proteins in such foods as meats and fish
                     Proteins
• the basic subunit (building block) of a protein is
  called an amino acid
• each amino acid has 4 parts around a central carbon
  atom:
                   Proteins
• A dipeptide is formed when there are 2 amino acids
  linked (see picture below).
• A polypeptide is formed when 3 or more amino acids
  (a.k.a. peptides) are linked together.
                     C. Lipids:
* contains C, H, and O
   * no fixed ratio of atoms
ex: fats and oils
* found in cell membrane
   * also used for high-energy storage
   * all lipids have two separate building blocks:

1. 1 glycerol- an alcohol with 3 -OH groups in its
   molecule
2. 3 fatty acids- a chain of carbon atoms to which
   hydrogen atoms are bonded; also has a carboxyl
   group (carboxyl=acids) at one end of the chain.
3 fatty acids and one glycerol make 1
            lipid molecule
             D. Nucleic Acids:
* contains C, H,O,N, and P (phosphorous) and
  sometimes (S) sulfur
* carries the genetic code
* building blocks are called nucleotides
* there are two types of nucleic acids
ex. DNA and RNA
                Nucleic Acids
DNA-deoxyribonucleic acid
  * found only in the nucleus
 * shape of a double helix
RNA-ribonucleic acid (will be taught in detail in
 packet #20)
  * found all over the cell
 * 3 types
 * shape varies according to the type
                  ENZYMES
• used to regulate the rate (speed) of chemical
  reactions
  * all enzymes are proteins
  * each chemical reaction in an organism requires
  its own specific enzyme
  (each chemical that is worked on by an enzyme is
  called a substrate)

* each enzyme can also be called an ORGANIC
  CATALYST
* enzymes are never changed by their reactions!
• Each enzyme has a specific area for linking up
  with its own specific substrate. This is called an
  ACTIVE SITE
• THE LOCK AND KEY MODEL
  1.) an enzyme and substrate that are compatible
  link up at the ACTIVE SITE.
  2.) This forms the ENZYME-SUBSTRATE COMPLEX
  where the enzyme goes to work
  (can put together or take apart a substrate.)
  3.) the enzyme and products separate: the
  enzyme is ready to work on another substrate.
Draw Enzyme Action:
Interactive
                  Enzymes
• remember all enzymes are proteins
• * sometimes they need "helpers"; these helpers
  are called COENZYMES (a.k.a. VITAMINS)

  enzymes are named for the chemicals that they
  "go to work" on……..
  1.) enzyme names always end in -ASE
   ex. LIPASE MALTASE LACTASE
   2.) the first part is what their substrate is
Cartoon
FACTORS THAT INFLUENCE (affect)
ENZYME ACTION:
1. temperature:

* the temperature at which enzymes are most
    effective is called the optimum temperature.
* If it gets too hot, the enzyme falls apart (called
    denatures) then it no longer works
    (like when you get a very high fever)
  FACTORS THAT INFLUENCE (affect)
         ENZYME ACTION
2. pH (the ph scale)
• the measure of how acidic or basic something
  is
• The pH at which enzymes are most effective is
  called the optimum pH
  FACTORS THAT INFLUENCE (affect)
         ENZYME ACTION
3. amounts of enzymes and substrates
* adding more of either the enzyme or substrate
  will increase the rate of the reaction...until
  you reach a point where the enzyme cannot
  work any faster- then the activity level of
  enzyme action levels off.

				
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posted:3/2/2012
language:English
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