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Proteins and Nucleic Acids. Amino acids are the building blocks of proteins. 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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Side chains (R groups) give amino acids their various properties (polar, nonpolar) • Amino acids combine to form polypeptides (polymers) via loss of ____ molecules
Protein FunctionMost diverse of allorganic 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)
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
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
How do Enzymes Speed Up Reactions? • Anabolic reactions • Bring two substrates together (greater chance of reaction) • Catabolic reactions • Stress bonds (greater chance of bonds breaking) http://www.lew-port.com/10712041113402793/lib/10712041113402793/Animations/Enzyme_activity.html
Factors Affecting Enzyme Activity • Temperature • pH • Concentration of Substrate Denaturing (enzyme changes shape, stops working)
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
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
Comparison of Nucleic Acids DNA • Double stranded • Deoxyribose • Bases: CGAT RNA • Single stranded • Ribose • Bases: CGAU
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