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54 Cards in this Set
- Front
- Back
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hydrogen bond
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bond that allows water to maintain its liquid state by providing strong cohesive forces between molecules
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hydrophobic
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cohesive forces of water squeeze hydrophic molecules away
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hyrophilic
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dissolve easily in water because they are polar
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hydrolysis
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process by which most living macromolecules are broken apart
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dehydration
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process by which most macromolecules are formed
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lipid
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molecule that has low solubility in water and high solubility in nonpolar organic solvents (hydrophobic)
six groups: -fatty acids -traicylglycerols -phospholipids -glycolipids -steroids -terpenes |
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fatty acids
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building blocks of lipids, long chains of carbons with carboxylic acid end
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Triacylglycerols/triglycerides
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-lipids
-fats and oils with a three carbon backbone called glycerol |
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adipocytes
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specialized fat cells whose cytoplasm contains mostly triglycerides
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phospholipids
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-built of glyerols but have a polar phosphate group, polar at the phosphate end, nonpolar at the fatty acid end (amphiphatic)
-think membranes! |
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Proteins/polypeptides
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-built from amino acids linked together by peptide bonds
-all proteins from 20 acids, 10 essential (not in body) -only differ from one another by r group or side chains |
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amino acid structure
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R
H2N-CH-COOH |
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primary structure
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number and sequence of amino acids
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secondary structure
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formation of alpha-helix or Beta pleated sheets(parallel or antiparallel)
-reinforced by hydrogen bonding(disrupted by proline) -conformation of protein |
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tertiary structure
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three dimension shape created by:
-covalent disulfide bonds between two cystein amino acids -hydrogen bonds -van der waals forces -electrostatic interactions -hydrophobic side chains |
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quaternary structure
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two or more polypeptide chains bonded together
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denatured
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when conformation is disrupted
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Collagen
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most abundant protein in the body
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glycoproteins
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proteins with carbohydrate groups attached
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cytochromes
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proteins that add color to the cell
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Carbohydrates
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made from carbon and water, most common: glucose
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glucose
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-most common carbohydrate
-exist in ring and chain form, ring form has two anomers -is oxidized for ATP or is polymerized to glycogen -liver regulates blood glucose level -end product of carbohydrate digestion |
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Starch and cellulose
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-found in plants only
-formed from glucose |
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alpha linkages/ beta linkages
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animals digest alpha linkages like that of starch and glycogen but bacteria can only digest beta linkages like that in cellulose
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Nucleotides
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composed of:
-five carbon sugar (pentose) -nitrogenous base -phosphate group -polymers of nucleotides -form nucleic acids DNA and RNA -joined by phosphodiester bonds |
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DNA
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-two nucleotide strands joined by hydrogen bonds to make a double helix
-Adenine to Thymine (2H bonds) -Guanine to cytosine (3H Bonds) -top 5-3, bottom 3-5 |
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RNA
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-single stranded
-Uracil replaces Thymine |
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Minerals
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dissolved inorganic ions
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Enzymes
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globular proteins that act as a catalyst
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catalyst
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-lowers the energy of activation for a reaction
-increases the rate of reaction -not consumed found in reactants and products -only small amount required -does not alter equilibrium concentrations |
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substrates
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reaction or reactants an enzyme works on
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active site
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position on enzyme where substrate bonds
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enzyme substrate complex
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name for when enzyme is bound to substrate
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enzyme specificity
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enzymes can only work on a specific substrate or group of closely related substrates: example- lock and key theory
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induced fit theory
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shape of enzyme and substrate are both altered upon binding
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saturation kinetics
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-as level of substrate increases so does rate of reaction, but increases lesser and lesser until it Vmax is reached
-Vmax is proportional to enzyme concentration |
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factors that affect enzymes
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temperature: as it goes up, reaction rate goes up until enzyme denatures and reaction slows
pH: optimal pH varies for each enzyme |
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cofactor
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non-protein that allows enzymes to reach optimal activity
-can be coenzymes or metal ions or minerals -many are vitamins or derivates of vitamins |
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Enzyme inhibition
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-process of inhibiting enzymes
-irreversible inhibitors: cant be reversed |
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competitive inhibitors
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-compete with substrate for active site
-resemble substrate -increased substrate concentration overcomes competitve inhibitors -increases Km but does not alter Vmax |
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noncompetitive inhibitors
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-bind noncovalently to an enzyme at a spot other than the active site and change the conformation of the enzyme
-cannot be overcome - lowers Vmax, Km unchanged (because enzyme affinity for substrate is unchanged) |
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enzyme regulation
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cells must regulate enzyme activity:
-proteolytic cleavage: enzyme is released in inactive form called zymogen or proenzyme, bonds are cleaved enzyme is activated -Allosteric interactions: modification of enzyme configuration resulting from binding of an activator (allosteric activators) or inhibitor (allosteric inhibitors) to specific binding site (allosteric enzymes have several binding sites) |
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negative feedback inhibition
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shuts down mechanism when it has produced sufficient product
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positive feedback
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product returns to activate the enzyme
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positive/negative cooperativity
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change in shape of enzyme from allosteric regulation can allow other substrates to bind more easily(positive) or not so easily (negative)
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enzyme classification
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-end in ase
-lyases: catalyses addition of one substrate to a double bond of a second substrate is called a synthase ligases: also govern addition reaction but require energy from ATP or other nucleotide kinase: phosphorylates to activate or deactive phosphatase |
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Glycolysis
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-occurs in both anaerobic and aerobic respiration
-breaks 6-carbon glucose into 2 3 carbon molecules -has a 6 carbon stage (which uses 2 ATP) and a 3 carbon stage -nets 2 ATP and 2 NADH -associate with pyruvate and NADH -occurs in cytosol (all living cells can do this) -3rd step is irreversible where the second phosphorylation commits the molecule to the glycolytic pathway |
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substrate level phosphorylation
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-formation of ATP from ADP and inorganic phosphate
-occurs at the end of glycolysis to form 2 ATP |
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Fermentation
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-anaerobic process
-recycles NADH back to NAD+ -includes glycolysis and produces 2 ATP |
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Enzymes and Cellular Metabolism
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When enzymes are inhibited by poision, there will be a build of of reactants and a dramatic reduction in products of the reaction which enzymes govern.
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Aerobic respiration
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-requires oxygen
-works on products of glycolysis(pyruvate and NADH) -occurs in the MATRIX of the mitochondria -inside matrix pyruvate-> acetyl CoA -produces 36 net ATPs, 1 NADH -> 2-3 ATPs, 1 FADH2 -> 2 ATPs |
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Kreb Cycle
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-each turn prodcutes 1 ATP (through substrate-level phosphorylation)
-3 NADH and 1 FADH2 -part of aerobic respiration, occurs in mitochondria matrix -1 glucose = 2 turns |
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Respiration
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Glucose + 02 -> CO2 + H20
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Electron Transport Chain
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-a series of proteins including cythochromes in the inner membrane of the mitochondria
-oxidizes NADH and ultimately accepted by OXYGEN -establishes a proton gradient in intermembrane space (lower pH than matrix) which propels protons through ATP synthase to make ATP through oxidative phosphorylation (2-3 ATP per NADH) -each intermediate molecule is reduced than oxidized |
