Flashcards in Fundamentals of Biochemical Reactions Deck (33):
Identify what free energy change indicates in terms of Gibbs free energy?
Delt G < 0 = spontaneous, Keq > 1, exergonic, rxn proceeds to right
Delt G > 0 = non spontaneous, Keq < 1, endergonic, rxn proceeds to left
ATP -> ADP + Pi
ATP -> AMP + PPi
PPi -> Pi + Pi
Delt G = -7.3 kcal/mol
Delt G = -10.9 kcal/mol
Delt G = -4.0 kcal/mol
Involves molecules that donate protons (acids) and accept protons (bases)
Transfer of an electron from one molecule to another. OILRIG
pH of blood
Blood buffering System equation
H + HCO3- H2CO3 CO2 + H2O
Carbonic anhydrase is between Bicarbonate and CO2 and H2O
Acid-base balance and kidneys
Kidneys remove H+ from blood in the form of NH4+ and reabsorb HCO3-. Low blood pH (metabolic acidosis) increases removal of H+ and reabsorption of HCO3- -> results in equation shifting to right. High pH (metabolic alkalosis) results in fewer H+ removed and less reabsorption of HCO3-.
Hypoventilation leads to a high concentration of CO2 and shifts the equation to the left, which causes and increase in H+ and a decrease in pH.
Hyperventilation leads to a low concentration of CO2 and shifts the equation to the right, which causes a decreases in the amount of H+ and an increase in pH.
Activation energy and speed the rate of the reaction. They do not increase or decrease the free energy, nor do theyt alter the conc of reactants and products.
Oxidoreducatases and examples
enzymes that transfer electrons from a donor to an acceptor. Ex. lactate Dehyrdogenase, oxidases,
Induced fit hypothesis
binding induces conformational changes in active site
Lock and key hypothesis
substrate is a perfect fit for active site
noncovalent interaction, stabilize active site, how they interact
small organic molecules, derived from vitamins. Two classes-> co-substrate and prosthetic (Heme)
Lactate dehydrogenase active sites
Essential AA: R, H, R
Enzymes need optimal...
pH and temperature
Gastric Proton pump inhibitors
AKA H+/K+ ATPase. Is found in the parietal cell lining gastric lumen, which pumps H+ into the lumen where it combines with Cl- to form HCl. Conditions such as heartburn and ulcers require decrease in gastric acid. Proton pump inhibitors are prescribed and reduce HCL production.
Same Vmax and increased Km
Lower Vmax and same Km
Lower Vmax and Lower Km
Inhibition of Metalloenzymes
These are enzymes that require metal ions as a cofactor such as Mg and Zn. Chelating of cofactors will inhibit enzyme activity.
Chelating Agents of Lead poisoning
Pb inhibits 2 important enzymes for heme biosynthesis and since Heme is a coenzyme of hemoglobin, RBC are not able to bind oxygen and deliver oxygen to the body. Symptoms of lead poisoning include abdominal pain, sideroblastic anemia, irritability, and headaches. Neurological defects indicate impaired nervous system and encephalopathy. Treatment for lead poisoning involves administering Ca-EDTA with dimercoprol. Since lead has a higher affinity for EDTA, lead will displace Ca and form Pb-EDTA, which can then be excreted out.
Irreversible Enzyme activation
Irreversible loss of function. Decrease Vmax and Km remains unchanged. This can only be overcome by synthesis of new enzyme.
Allosteric Enzymes vs Enzyme kinematics
Sigmoidal curve vs hyperbolic
Same catalytic function but different primary sequence
Troponin in Myocardial infarction
Calcium binding causes conformational change, transmitted to tropomyosin, allowing myosin to bind to actin filaments. Troponin cTn-1 used as biomarker for detection of MI when found in serum.