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Published byMyrtle Rich Modified over 9 years ago
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Polymers (long chains) of AMINO ACIDS –arranged in specific sequence –linked by PEPTIDE BONDS –range in length from a few to 1000+
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AMINO ACIDS building blocks of proteins there are 20 common amino acids structure of an amino acid: elements included in a protein: -carbon -hydrogen -oxygen -nitrogen -sulfur (usually)
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Amino acids are linked together through DEHYDRATION SYNTHESIS to form PEPTIDE BONDS
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PROTEIN STRUCTURE a protein’s function depends on its specific 3-D shape
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Protein Shape: determined by environmental conditions DENATURATION: protein loses its natural shape, and therefore loses its function! This can be caused by: –extreme heat –pH changes
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Functions of Proteins structural support (e.g. hair, nails) signaling (e.g. hormones)
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Functions of Proteins movement (contraction of muscles) transporting oxygen in the blood
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Functions of Proteins defense (antibodies of immune system) catalysis of reactions (ENZYMES)
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PROTEINS WORKING AS ENZYMES ENZYMES: are proteins control the speed of reactions (often they increase the speed of reactions)
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are not changed or “used up” by a reaction; can be used over and over
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each enzyme is specific to a SUBSTRATE SUBSTRATE = the substance the enzyme acts on Substrate==> enzyme-sub.==> product + complex + enzyme enzyme
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ACTIVE SITE = region of an enzyme which binds to the substrate –is usually a pocket or groove on surface –compatible “fit” between shape of enzyme’s active site and shape of substrate
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Factors Affecting Enzyme Activity 1.Temperature: –as temp increases, reaction rate increases –BUT, if temp gets too high, enzyme denatures and loses its shape and function –optimal range for human enzymes: 35-40°C
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2.pH: -optimal range for most enzymes: pH 6-8 *some enzymes operate best at extremes of pH (e.g. digestive enzyme pepsin, found in the acidic environment of the stomach, works best at pH 2)
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nucleic acids store and transmit hereditary information Two types of nucleic acids: 1.DNA 2.RNA
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Structure of Nucleic Acids polymers made up of monomers called NUCLEOTIDES Elements present: -carbon -hydrogen -oxygen -nitrogen -phosphorus
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each nucleotide consists of: 1. a simple sugar -deoxyribose in DNA -ribose in RNA 2. phosphate group 3. a base (e.g. in DNA, the bases are A, G, C, and T)
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nucleotides are joined together in DEHYDRATION SYNTHESIS results in a “backbone” with a repeating pattern of sugar-phosphate- sugar-phosphate...
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1. DNA = Deoxyribonucleic acid forms the genetic code - the instructions for the proteins (amino acid sequences) of an organisms’ proteins is copied and passed from one generation of cells to another
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2. RNA = Ribonucleic acid functions in the actual synthesis of proteins coded for by DNA
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