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SECTION 2 : CARBON COMPOUNDS
Chapter 3 - Biochemistry
Carbon Bonding
Organic Compounds: made mostly of carbon atoms
Inorganic Compounds: do not contain carbon
Carbon can bond with itself: It can form straight
chains It can form branched
chains It can form rings
Functional Groups
Functional groups are the portion of a molecule that gives the molecule it’s particular properties. They are also active in a chemical reaction.
Functional GroupFormulas/ Chemical
StructuresCommon Name Biological Importance
CarboxylCarboxylic Acids
Polar – water solubleAcid in Amino AcidsAct as buffers in organisms
HydroxylAlcohols:Methanol, Ethanol
Polar – whole molecule is water soluble
Carbonyla. Aldehyde
b. Ketone
AldehydesGlyderaldehydeFormaldehydeKetonesAcetone
Polar – water solubleFunctional group in carbohydratesMetabolic intermediates
Ketones = nonpolar
Amino
AminesAmino Acids- Glycine
PolarFound in amino acidsAmmonia waste from protein
SulfhydrylCystine(amino acid)
Stabilizes proteins
PhosphateOrganic Phosphates
Polar; AcidicFound in DNA/RNAUsed in energy transport (ATP)
Large Carbon Molecules
Monomers: building blocks of organic molecules
Polymer: molecule made of multiple monomers that are linked together
Macromolecules: large polymers Ex: carbohydrates, lipids, proteins and nucleic acids
Making and Breaking Polymers
Condensation Reaction: monomers are linked to polymers and water is released
Hydrolysis: break down of polymers using water The reverse of a
condensation reaction
Energy Currency
Life processes require a constant supply of energy
Adenosine Triphosphate (ATP) a high energy compound found in cells Covalent bonds hold the
phosphate groups together The bond that attaches the
last phosphate group to the rest of the molecule is easily broken releasing energy for cell work
SECTION 3 : MOLECULES OF LIFE
Chapter 3 - Biochemistry
Molecules of Life
4 Molecules of Life Carbohydrates (sugars) Proteins (enzymes) Lipids (fats) Nucleic Acids (DNA and RNA)
Carbohydrates
Carbohydrates are organic compounds composed of carbon, hydrogen and oxygen General ratio is 1C:2H:1O or
(CH2O)n
Monosaccharides: monomer (building block) of a carbohydrate Examples: Glucose, Fructose
and Galactose All 3 monomers have the same
formula C6H12O6, but they each have different structures - isomers
Glucose
Fructose
Carbohydrates
Disaccharides: double sugar (two monosaccharides bonded together) The reaction that joins the two monosaccharides
together is called a condensation reaction
Examples:
SucroseLactose Sucrose
Carbohydrates
Polysaccharides: made of 3 or more monosaccharides bonded together Examples:
Glycogen (in animals): energy storage Stored in liver and muscle, made of glucose molecules
Starch (in plants): energy storage Made of glucose molecules
Cellulose (in plants): used for structure cell wall
Proteins
Proteins are organic compounds made of carbon, hydrogen, oxygen and nitrogen
Monomer = amino acids 20 different amino acids Functional groups of
amino acids: -COOH, NH2
What gives the amino acid its specific identity is it’s R-group R-groups can be simple
or complex
Proteins
Dipeptides are two amino acids bonded together The bond between amino acids is called a peptide
bond Peptide bonds are formed during a condensation
reaction
Proteins
Polypeptides: very long chains of amino acids
Form larger proteins, which are usually made of more than one polypeptide chain
4 levels of structure for polypeptides Primary: linear sequence
of amino acids Secondary: polypeptide
forms α-helices and β-sheets
Tertiary: R-groups interact with one-another
Quaternary: more than one polypeptide chain making a protein
Proteins
Enzymes: Protein (or RNA) molecules that act as biological catalysts
How enzymes work: Induced Fit Model of Enzyme Action
Enzyme reactions depend on the physical fit between the enzyme and its substrate (the reactant being catalyzed)
Active Site: portion of the enzyme that the substrate fits into
The linkage between the enzyme and the substrate causes a slight change in the enzyme’s shape which puts a strain on the substrate bonds
The enzyme releases the products and remains unchanged
Temperature and pH effect an enzyme’s activity
Enzyme Action
http://www.biotopics.co.uk/other/hienz.html
Lipids
Lipids: large, nonpolar organic molecules DO NOT dissolve in H20
Building blocks of lipids: Glycerol:
Functional group = -OH
Fatty Acids: unbranched carbon-chains Functional group = -COOH
Lipids
Fatty Acids Continued: Fatty acids can be saturated (each carbon is bonded to 4
other things – “full”)
Fatty acids can be unsaturated (when the carbon atoms form double bonds with each other in the carbon chain)
Lipids
Types of Lipids: Triglycerides: 3 fatty acids attached
to a glycerol
Phospholipids: 2 fatty acids attached to a glycerol, with a phosphate attached to the 3rd carbon of the glycerol Makes-up the cell membrane of cells
Hydrophilic head
2 Fatty acid tails
Lipids
Types of Lipids Continued Waxes:
Structural lipids Fatty-acid chains connect to an alcohol
chain Water-proof and provide protection
Steroids: Made of 4 fused carbon rings
Functions• Hormones (testosterone)• Found in cell membranes
(cholesterol)
Nucleic Acids
Nucleic Acids: store and transfer genetic information 3 parts of a nucleic acid:
Phosphate Group Sugar Nitrogenous Base
Three combined forms the nucleotide 2 types of Nucleic Acids
DNA: stores genetic information for an organism RNA: stores and transfers information from DNA that
is needed to make proteins