Elements & Biochemistry

Contents:            1.    Elements          2.    Organic Compounds               a.    Lipids               b.    Proteins               c.    Nucleic Acids               d.    Enzymes

Elements

Major Elements (bigger quantities found in living things)- H, O, C, N, S, P

Trace Elements- (smaller quantities found in living things) � Mg, Ca, Fe, K, Na, Zn, F, Cl, Cu, I, Co, Mn, Br, Se

Electrons �

Protons +

Neutrons 0

Compounds

I.      Inorganic- do not contain carbon characterized by ionic bonds

         Ionic bonds- formed by the loss and gain of electrons

                  Na )  )  )                           Cl )  )  )

                       2-8-1                              2-7-8

-Atoms like to have a complete outer shell ( 8 electrons). So if you take the 1- from the Na last shell and give it to Cl who has 7- they both end up having complete outer shells.

-In this case Na becomes a positively charged and Cl becomes negatively charged. Na has more electrons than protons because it started out with 11 and 11 but now there are 11 protons and 10 electrons. Cl has more electrons than protons because it added and electron which it took from the Na.

-Ion � electrically charged particle

    a)     H₂0- main component of cytoplasm (very stable)

    b)    Acids- substances which give off Hydrogen ion in solution (H+)

    c)     Bases (alkalis) � substances which give off Hydroxide (OH)- in solution

    d)     Salts- formed by a reaction between a acid and a base

pH Scale- measures acidity and alkalinity

    0         Acids        7.00        Bases        14

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Organic Compounds

II. Organic Compounds- all contain carbon, characterized by covalent bonds

     Covalent Bonds- formed by sharing electrons

- If an atom has 4 electrons on its outer shell it is strong enough to keep the electrons it has but not strong enough to take electrons.

�         C- always has 4 bonds

�         N- always has 3 bonds

�         O- always has 2 bonds

�         H- always has 1 bond

Families of Organic Compounds

a)     Carbohydrates

b)    Lipids (fats)

c)     Protein

d)     Nucleic Acids

e)     Vitamins

     Carbohydrates- carbon, hydrogen, oxygen (H and O are always in the same ratio 2:1= H2O)

Made up of sugars and starch

      Sugars

-Properties

  Excellent source pf quick energy

  Sweet

  Soluble in H2)

  Burns (burnt sugar → caramel)

         Sub Families

  a)     Monosaccharide

          -*Glucose- C₆ H₁₂ O₆ 

          - Fructose- C₆ H₁₂ O₆

          - Galactose- C₆ H₁₂ O₆

  b)    Disaccharides (2 monosaccharides put together)

          -  Sucrose  - C₁₂ H₂₂ O₁₁

          -*Maltose   - C₁₂ H₂₂ O₁₁

          -  Lactose (milk sugar)  - C₁₂ H₂₂ O₁₁

Empiric Formula- List of ingredients, the number of atoms of each element found in a single molecule of the substance

Structural Formula- actual arrangement of atoms in a molecule

-When a disaccharide is formed from 2 monosaccharides it loses H20 because the H can�t have more than 1 bond and the O can�t have more than 2 bonds, so we lose H20.

Dehydration Synthesis- processes in which 2 or more small molecules combine to form a larger molecule by the removal of H20.

Hydrolysis- process in which a large molecule is broken up into smaller molecules by the addition of H20.

C₁₂ H₂₂ O₁₁ → 2 C₆ H₁₂ O₆

A)   Carbohydrates

       1)    Sugars

       2)    Starches (polysaccharides)

               a)  Properties

                    - Excellent source of stored energy

                    - Animal starch = glycogen stored mostly in liver

                    - Insoluble in H20

                    - Polymer = chain of repeating units

                     A starch molecule consists of two parts:

                     1)      Amylose- straight chain of glucose molecules

                     2)    Amylopectin- branched chain of glucose molecules

       3)    Cellulose

              - only found in plant cells

              - found in the cell wall

              - big polysaccharide

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Lipids

A.    All contain C, H, O

B.    The O: H ratio is always greater than 2:1, but it is not constant

C.    Properties

           -Greasy

           -Burn

           -Excellent source of stored energy

           -Insoluble in H₂O

           -              -Leaves a translucent stain on paper (can�t see through it but light can pass through it)

D.    Functions of Lipids

           - Energy source

           - Lubrication

           - Insulation (keeps in heat)

           - Protection

           - Important part of cell membranes

E.    Each Lipid molecule consists of:

    a.    3 Fatty Acids- hydrocarbon chain

    b.    1 Glycerol

             *3:1 ratio of Fatty Acids: Glycerol

F.    Types of fats:

    a.    Saturated � there are only single bonds in the hydrocarbon chain (less healthy). They can get stuck in your arteries.

            (ex: cheese, red meat, deli, whole milk products, coconut oil, palm oil, yolk of eggs)

                    - Derived from animals

                    - Usually solid at room temperature

    b.    Unsaturated- there is at least one double bond in the hydrocarbon chain (healthier). This fat is easier for your body to break down.

            (ex: corn oil, vegetable oils, fish)

                    -  Liquid at room temperature

                    -  Derived from plants

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Proteins

A.     Elements: C,H,O,N,S (Cohns)

      G.    Types of Amino Acids: (only in animals, plants can synthesize all 20 in their cells)

                1.  Essential- those that can�t be synthesized by the human body (we get them from food)

                2.  Unessential- those which can be synthesized on the body

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Nucleic Acids

Properties

          - High energy source content

          - Polymers � chain of nucleotides   

Each nucleotide consists of:

    1)      5 carbon sugar- represented with a �

                                                               �_ �

    2)    Phosphate group- represented with a circle

    3)    Nitrogenous Base- represented with a rectangle

Enzymes

• Specialized proteins -most enzymes are made of amino acids (a non protein part) and a co-enzyme (made of vitamins)

• Organic Catalysts- regulate speed of chemical reactions (usually increasing the speed) with out changing as a result of the reaction, reusable

Substrate- the substance with which an enzyme reacts

-Most enzymes are bigger than their substrates

Active Site- the part of the enzyme molecule that corresponds to the shape of its substrate

Enzyme Specificity- each enzyme can react only with its own substrate (lock & key)

How an Enzyme Works:

1. Formations of an enzyme � substrate complex (substrate and enzyme connect)

2. Bond(s) is (are) broken

3. H & OH are added to complete the molecular structure of the products (hydrolysis only)

4. The products separate from the enzyme

5. The enzyme is available for another reaction

Factors Affecting Enzyme Activity:

1. pH- optimum pH about 7

           there is an exception in the stomach because the stomach is full of acid so in the stomach the optimum pH is about 1.5-2. In the small intestine the optimum is about 8.5.

2. Temperature- optimum temperature is 37C

           If the temperature is lowered below 37C enzyme activity decreases and would eventually stop at 0C. if the temp is raised back to 37C then the enzyme resumes its former levels.

           At temperatures above 37C enzyme activity drops rapidly and eventually stops at around 100C. If it gets to 100C it will never work again, even if you get it back to 37C. this is called enzyme denaturation.

Enzyme Detnaturation- permanent destruction of enzymes (after you reach 45-50C. the reason is because the high temperatures change the active site and it doesn�t maintain its shape.

3. Enzyme Poisons- cyanide (deadly poison)- interferes with respiratory enzymes in the mitochondria.

4. Relative Concentration of Enzymes and Substrates

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