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Explore the fundamental concepts of biochemistry, including the chemistry and versatility of the carbon atom, carbohydrates, lipids, proteins, and nucleic acids. Learn about their structures, functions, and importance in biological systems.
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BIOCHEMISTRY • The chemistry of the carbon atom • Versatility of the carbon atom • Bonds readily to itself, forms chains, rings, single and double bonds • Hydrocarbons • Isomers • Polymers
I. Carbohydrates • Sugars and their polymers • CHO in a 1:2:1 ratio • An –OH group is attached to each C except one which is double bonded to Oxygen • Most common: • Triose 3C glyceraldehyde • Pentose 5C ribose • Hexose 6C glucose
A. Monosaccharides • Simple sugars • C6H12O6 – glucose, fructose, galactose • Arrangement of individual atoms makes them different compounds • Glucose – hexose – building block for more complex sugars • Fructose – fruit sugar • Galactose – milk sugar
B. Disaccharides • 2 monosaccharides joined by a glycosidic linkage through dehydration synthesis • Maltose = glucose + glucose (brewing beer) • Lactose = glucose + galactose (milk) • Sucrose = glucose + fructose (table sugar)
C. Polysaccharides • Polymer of a few hundred or thousand monosaccharides • 2 important functions: • 1. Energy storage (starch and glycogen) • 2. Structural support (cellulose and chitin) Starch = alpha linkage Cellulose = beta linkage
II. LIPIDS • Waxy or oily organic compounds • Nonpolar; CHO in no particular ratio • Fats, phospholipids, steroids • Functions: • Energy storage • Bio membranes • Chemical messengers • Insulation • Cushion vital organs
A. Fats • Glycerol and 3 fatty acids • Simple fat = triglyceride • Properties depend on the fatty acids that it is composed of • Saturated vs. unsaturated fatty acids
B. Phospholipids • Glycerol, fatty acids (2) and a phosphate group (negatively charged) • AMPHIPATHIC
C. Steroids • Lipids with 4 fused carbon rings with various functional groups attached • Amphipaathic • Cholesterol, hormones
III. PROTEINS • Polymers of amino acids • Amino acids are the monomers
III. PROTEINS cont’d • Amino acids can form covalent bonds with each other • 20 AA in nature – each has a different “R” group • R groups can be • Polar • Nonpolar • special
III. PROTEINSFormation • Two amino acids form a peptide bond through dehydration synthesis • Peptide bond formed between acid group of one amino acid and and amino group of another • 40 – 1,000 AA in MOST cellular proteins
PROTEINSStructure • Primary – linear sequence of amino acids • Secondary – folding due to H bonds (weak forces) (alpha helix, beta pleated sheet) • Tertiary – more folding of helix due to hydrophobic/hydrophilic interactions of R groups • Quaternary – two or more chains held together by weak forces
PROTEINSFunctions • Membrane structure (integral and peripheral) • Enzymes (biological catalysts) • Motion (muscle contraction) • Energy (last resort) • Transport (hemoglobin) • Hormones (cellular control) • Regulation of gene function • Protection (immune system)
III. PROTEINS cont’d • Denaturing occurs when temperature or pH changes or through treatment with urea • 3D structure is destroyed – no function • Primary structure is still intact; peptide bonds are strong covalent bonds that cannot be broken by change in pH, temp, etc
IV. NUCLEIC ACIDS • DNA and RNA, molecules which contain directions to make proteins; determine physical appearance, internal makeup, etc • Building blocks = nucleotides • Nucleotide = sugar (5C), phosphate and a nitrogenous base • In DNA, deoxyribose, phosphate, and one of four N bases (adenine, thymine, cytosine, guanine)
IV. NUCLEIC ACIDS cont’d • RNA = ribose, phosphate group, and one of 4 N bases (adenine, uracil, cytosine and guanine) • DNA = double helix; RNA single stranded • Over 100 million base pairs in one human DNA molecule • Base pairing rules • In DNA bases joined together by H bonds to make up rungs of ladder