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Published byDominick Fowler Modified over 9 years ago
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Proteins and Nucleic Acids
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Amino acids are the building blocks of proteins
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Side chains (R groups) give amino acids their various properties (polar, nonpolar) Amino acids combine to form polypeptides (polymers) via loss of ____ molecules
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Protein Function Most diverse of all organic compounds Body Structure - Hair, muscle, collagen, bones, feathers, spider webs Mobility/transport - actin and myosin in muscles, hemoglobin Defense - antibodies Storage - Casein in milk, proteins in eggs, seeds Hormones - insulin Catalysts for all reactions within cells (enzymes)
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Enzymes Enzymes = Organic catalysts Speed up chemical reactions Not changed by the reaction Lower “start up” energy (activation energy) required for reaction Extremely specific –Each chemical reaction requires a different enzyme
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Enzyme Activity: Lock and Key Model Substrate = molecule acted on by enzyme Active site = surface cleft on enzyme that binds to substrate Induced fit = enzyme changes shape of active site so substrate can bind
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How do Enzymes Speed Up Reactions? http://www.lew- port.com/10712041113402793/lib/10712041113402793/Ani mations/Enzyme_activity.html Anabolic reactions Bring two substrates together (greater chance of reaction) Catabolic reactions Stress bonds (greater chance of bonds breaking)
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Factors Affecting Enzyme Activity Temperature pH Concentration of Substrate Denaturing (enzyme changes shape, stops working)
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Why is protein structure important for its function? Shape defines its function Shape is obtained by the precise interactions of the R groups R groups change - protein folds differently (sickle cell anemia) Sensitive to changes in cell environment - anything that will change/break H bonds, acidity/basicity
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Nucleic Acids Building blocks are nucleotides Each nucleotide made up of –A 5-carbon sugar RNA: ribose DNA: deoxyribose –Nitrogenous base Adenine, Cytosine, Guanine, Thymine (DNA only), Uracil (RNA only) –Phosphate group(s) Basic Structure of a Nucleotide
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Comparison of Nucleic Acids DNA –Double stranded –Deoxyribose –Bases: CGAT RNA –Single stranded –Ribose –Bases: CGAU
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Function of Nucleic acids DNA contains all the info the cell needs to survive and carry out its functions RNA - carries out the job that is specified on DNA (makes proteins) ATP (Adenosine triphosphate) is the fuel for cell to work Coenzymes help enzymes do their work eg NAD, FAD Messengers within cell e.g. cAMP
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