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27 Cards in this Set
- Front
- Back
Nonpolar R group
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Hydrophobic, do not form hydrogen bonds, coelesce in water.
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Polar R group
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Hydrophillic. Dissolve in water easily, form hydrogen bonds.
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monomers
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a molecular subunit with only one part, amino acid, nucleotide, or a sugar. When they bind (polymerize) together, they are called polymers (more than one part)
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Polymerization
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the process of linking monomers together. requires energy and is nonspontaneous. Done through condensation reactions, which release a water molecule. AKA dehydration reactions.
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Hydrolysis
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Reverse of Condensation. breaks polymers apart by adding water
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Oligopeptides
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A polypeptide consisting of less than 50 amino acids.
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Proteins
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A polypeptide consisting of more than 50 amino acids.
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polypeptide backbone characteristics
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-R group orientation
-Directionality free amino group on the left is the N terminus and the free carboxyl group on the right is the c terminus -Flexibility single bonds on either side can rotate. |
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Protein function
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-Catalysis-enzymes, speed up chemical reactions
-defense-antibodies -movement-motor and contractile proteins -signaling-cell to cell communication -structure-define cell shape and comprise body structures -transport-transport proteins |
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Proteins Primary Structure
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Unique sequence of amino acids. the R group makes it unique, just one amino acid alteration can change the structure and function of the protein
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Secondary structure
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hydrogen bonds between the carbonyl group of one amino acid and the amine group of another makes this.
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tertiary structure
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interactions between r groups or between r groups and the polypeptide backbone.
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vane der waals reactions
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weak electrical interactions between hydrophobic side chains.
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covalent disulfide bonds
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form between sulfur containing r groups
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quaternary structure
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the bonding of two or more polypeptide subunits
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molecular chaperones
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specific proteins that help proteins fold. Many belong to a family of molecules called heat shock proteins. produced in high quantities after cells experience high temperatures, that make the proteins lose their tertiary structures, they help aid proteins in speeding up their folding into their normal shape after denaturation has occurred
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prions
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improperly folded normal proteins that are present in normal individuals. The only thing that is different in the protein is the folding, they can also induce normal proteins to go into an abnormal shape.
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catalysis
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acceleration of the rate of a chemical reaction due to a decrease in the free energy of the transition state, called the activation level.
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Activation energy
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the amount of energy required to initiate a chemical reaction; specifically, the energy required to reach the transition state.
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Enzyme functions
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1. bring reactants together in precise orientations
2. stabilize transition states. |
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Active site
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on the enzyme, the substrates bind and react here.
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induced fit
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when many enzymes go under a conformational change when the substrates are bound to the active site.
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Enzyme catalysis has 3 steps:
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1. Initiation-substrates are precisely orientated as they bind to the active site.
2. Transition state faciliation-interactions between the substrate and active site r groups lower the activation energy 3. termination-reaction products are released from the enzyme |
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cofactors
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Some enzymes require these to function normally. they are either metal ions or organic molecules called coenzymes
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competitive inhibition
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inhibition of an enzymes ability to catalyze a chemical reaction via a nonreactant molecule that competes with the substrates for access to the active site.
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allosteric regulation
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when a molecule causes a change in enzyme shape by binding to the enzyme at a location other than the active site. can activate or deactivate the enzyme.
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The rate of enzyme catalyzed reaction depends on
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1. substrate concentration
2. the enzymes intrinsic affinity for the substrate 3. temp 4. pH |