Ac Bio Chapter 3-Biochemistry

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Objectives: Students should be able to…….
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-Describe the structure of a water molecule.
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-Explain how water’s polar nature affects its ability to
dissolve substances.
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-List two of water’s properties that result from hydrogen
bonding.
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Organic: Substances that contain the element Carbon
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All living things or things that were once alive are organic
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Water is an Inorganic molecule making up 70% of the
average cell
Covalent bonds between two Hydrogen and one Oxygen
atom
Disassociates into OH- and H3O+
Considered to be a polar compound because it shows
electronegativity. It has a slight charge on both ends.
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Waters polarity allows it to have certain properties.
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Cohesion- Allows water to be attracted to itself
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Adhesion- Allows water to be attracted to other surfaces
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Capillarity- ability to move through fine pores or upward
through narrow tubes against gravity.
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This can allow for……
o Nutrients to get to all parts of plant
o Keep plant from changing temperature easily
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SO what is an Aqueous solution?
o Solution where water is the solvent
o Water is often referred to as the “ Universal Solvent”
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Carbon bonds to itself to form different molecular
structures
o Straight chains
o Branched chains
o Rings
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Single Bond
o Two atoms share a single pair of electrons
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Double Bond
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Triple Bond
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Functional Groups- clusters of atoms that influence the
properties of the molecules they compose.
o The structural building block that determines the characteristics of
the compound.
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Alcohol
o Has a hydroxide attached to one of the carbon atoms.
o Alcohol is a polar molecule
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Monomers
o Smaller and simpler molecules
o Also known as building blocks
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Polymer
o Consists of repeated, linked units.
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Macromolecules
o Large polymers
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Condensation Reaction
o Monomers link to form polymers through a chemical reaction
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Figure 3-8
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Glucose and Fructose combine to form Sucrose
2 Sugar monomers link by a C-O-C bridge
Glucose releases OHFructose releases H+
OH- and H+ combine to form water
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Hydrolysis Reaction
o The breakdown of some complex molecules, such as polymers.
o The reversal of a condensation reaction
o The addition of water can break some bonds that hold compounds
together.
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Four main classes of organic compounds are essential to
the life processes of all living things
o Carbohydrates
o Lipids
o Proteins
o Nucleic Acids
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Carbohydrates
o Organic compounds of C,H, and O
o Ratio of 2 Hydrogen atoms : 1 Oxygen atom
o The number of Carbon atoms varies
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Monosaccharides
o 1 sugar ring
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Disaccharides
o 2 sugar rings
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Polysaccharides
o 3 or more sugar rings
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Monosaccharides
o A monomer of a carbohydrate
o Simple sugar containing carbon, hydrogen, and oxygen in a 1:2:1
ratio
o Single ring structure
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Formula
o C6H12O6
o (CH2O)n
o n= any whole number 3-8
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Glucose
o Manufactured by plants during photosynthesis
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Fructose
o Found in fruits/sweetest type of sugar
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Galactose
o Found in milk
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Isomers
o Molecules with the same chemical formula, but different structural
formulas.
o Glucose, Fructose, and Galactose are all C6H12O6 but the atoms are
arranged differently.
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Disaccharide
o Formed when 2 monosaccharides are joined through a
condensation reaction.
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A. Sucrose
o Glucose + Fructose
o Found in sugar cane and sugar beets
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B. Lactose
o Glucose + Galactose
o Found in milk
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C. Maltose
o Glucose + Glucose
o It is found in beverages, beer, cereal, pasta, potatoes and in many
processed products which have been sweetened.
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Polysaccharides
o A complex molecule composed of three or more monosaccharides
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A. Glycogen
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B. Starch
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C. Cellulose
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A. Glycogen
o Stored energy source for animals
Glucose Vid 4min
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B. Starch
o Stored energy source for plants
o The major sources of starch
Granules of wheat starch, stained with
intake worldwide are the
iodine, photographed through a light
cereals (rice, wheat, and maize)
microscope
and the root vegetables like
potatoes
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C. Cellulose
o Polysaccharide that gives plants cell strength and rigidity.
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Lipids
o Long carbon/hydrogen chains
o Harder to break down and get energy back
o Not water soluble like other organic compounds
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A. Fats
B. Oils
C. Waxes
D. Steroids
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Lipid Structure
o Fatty acids have a polar carboxyl head and a nonpolar hydrocarbon
tails.
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Fatty Acids
o The monomers that make up most lipids
o Made of long straight chains of carbon-hydrogen, with a carboxyl
group attached to one end and a hydrocarbon at the other.
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Properties of lipids
o Carboxyl end is polar and is attracted to water
o Because it likes water it is called hydrophilic
o The hydrocarbon chain is non polar and is hydrophobic
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Three kinds of lipids exist….
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A. Triglycerides (Fats)
o Consist of three fatty acids and a glycerol
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2 Types of Triglycerides
o 1. Oils
• Liquid at room temperature
• Unsaturated fatty acids
• Consist of double bonds
• Not all of the H are available to bond with C
• Found in seeds
• Polyunsaturated
• Many double bonds
• Examples: olive, peanut, and corn oil
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2. Fats
o Solid at room temperature
o Saturated fatty acids
• All carbons bonded with H and contain NO double bonds
• Usually found in animals
o Examples:
• Beef fat, cheese, butter
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Hydrogenation
o The adding of hydrogen atoms to an unsaturated fat to make it
saturated
No Lipase in body to
break it down
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Waxes
o Consists of long fatty acid chain joined to a long alcohol chain
o Longs C-H chains make the waxes waterproof
o Used as a protective covering for plants (cuticle) and animals
(earwax)
o The most commonly known animal wax is beeswax
A lava lamp is a novelty item that contains
wax melted from below by a bulb. The wax
rises and falls in decorative, molten blobs.
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Steroids
o Consist of 4 carbon rings
o Not composed of fatty acids
o Classified as a lipid because they don’t dissolve in water
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Proteins
o Organic compounds of C,H,O and Nitrogen
o Important within cells of all living things
o Made of amino acids
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Amino Acids
o The monomers of proteins
o 20 different amino acids, all have the same basic structure
• The (R) group changes from amino acid to amino acid
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Dipeptide
o Formed when 2 amino acids are joined together by a peptide bond
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Polypeptides
o Long chain of amino acids
o Proteins are made of 2 or more polypeptides
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Enzymes
o Proteins that act as catalysts
o Substance that speeds up chemical reactions without being
affected by the reaction themselves
o Side note: If the enzyme is not present, the reaction would still take
place
o Enzymes lower activation energy of the reaction.
o Enzymes are substrate specific
o Also called “Lock and Key Fit”
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Enzymatic process
o 1. Enzymes hook on to the specific reactants that are going through
the reaction (Substrate)
• One enzyme hooks with specific substrate
• Lock and key fit
o 2. The enzyme begins to weaken the bonds inside the substrate
(lowering activation energy)
o 3. Reaction takes place
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Nucleic Acids
o Large organic molecules that direct…..
• Heredity
• Formation of proteins
o Two types of Nucleic Acids
• DNA
• RNA
o Monomers of Nucleic Acids are called Nucleotides
• There are three parts of a nucleotide
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Deoxyribose sugar
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Phosphate group
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Nitrogen base
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