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421 Cards in this Set
- Front
- Back
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Catabolism
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1. Degradative reactions of carbohydrates, lipids, and proteins into usable or storage forms of energy.
2. Conversion of complex molecules into smaller molecules |
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Anabolism
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1. Chemical reactions leading to the formation of large, complex macromolecules from smaller precursors.
2. Requires expenditure of energy in the form of ATP or NADH. |
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Examples of anabolism
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1. synthesis of macromolecules
2. muscle contraction 3. active ion transport 4. thermogenesis |
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Examples of catabolism
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1. energy production
2. carbohydrates 3. lipid 4. protein |
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Catabolism usually requires ____
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oxygen
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Exergonic reactions release ____
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ATP
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Many exergonic reactions are ____
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oxidative
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Liver and pancreas do ____ and _____ reactions
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secretory, biosynthetic
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Skeletal and cardiac systems take metabolic energy and convert it to ____ energy
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mechanical
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ATP is a critical link and uses ____ as a cofactor
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Mg 2+
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ATP stands for _____
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adenosine 5'-triphosphate
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hydrides are transferred from substrates to NAD+ by ______
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dehydrogenases
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Cycles are more efficient and require less E than linear (T/F)
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true
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NAD+ stands for _____
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nicotinamide adenine dinucleotide
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Thermodynamics of biological systems
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the relationship of the concentration of reactants and products in combination with the environment to determine if a rxn will proceed spontaneously or if it will require an input of energy to proceed
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the first law of thermodynamics
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the total energy of a system and its surroundings are constant
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equation representing the first law of thermodynamics
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delta E=Eend-Estart
=Q(heat)-W(work) |
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Delta E can be used to predict if a reaction will proceed spontaneously b/c the equation does not take into account the surrounding (T/F)
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False, it cannot be used
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Relationship b/w entropy and Free E
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the first law shows that the change in energy as a function of a rxn depends solely on the difference b/w the E at the end of the process minus the E at the beginning of the process. It is independent of the path of the transformation.
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The second law of thermodynamics
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A process can occur spontaneously only if the sum of the entropies of the systems and its surroundings increases
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Delta S (system) _ delta S (surroundings _____ 0
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>
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Spontaneous delta S (system) can increase if ______ increases
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delta S (surroundings)
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Formation of highly ordered biological structure is feasible b/c the decrease in the system is more than offset by an increase in ____
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entropy of its surroundings
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Two problems using entropy as a predictor of spontaneity:
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1. entropy changes are not readily measured
2. requires the knowledge of the entropy change of the surroundings as well as the system of interest |
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Instead of using entropy as a predictor of spontaneity, use ____
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free E (combines delta E and delta S)
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Delta G = ____
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change in free energy of a system undergoing a transformation at constant pressure (P) and temperature (T)
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Delta H=_____
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change in enthalpy of the system
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Delta S = _____
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change in entropy of the system
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Do properties of surroundings enter the Gibbs Free E equation?
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no
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Gibbs Free E equation
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Delta G = Delta E - TdeltaS
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What do we use instead of delta H? What is left out of the equation?
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Delta E
PdeltaV is left out because delta V is small for all biochemical reactions |
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The change in free E of a reaction depends on both ____ and _____ of the system
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change in internal E and entropy
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Celsius to Kelvin
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C + 273 = K
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A reaction can occur spontaneously only if delta G is _____
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negative
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A system is at equilibrium and no net change can take place if deltaG = ___
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zero
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An input of energy is required to drive the reaction if deltaG is ____
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positive
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Delta g depends on the path of transformation (T/F)
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F, does not depend on the path, only the free E of the products-Free E of reactants
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Delta G provides no info about the rate of the reaction (T/F)
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True
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standard state for biochemical reactions
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ph=7
Activity of H = 1 value of water = 1 standard free E = 0 |
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Relationship of deltaG to Keq
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DeltaG=deltaGprime + RT Ln (Keqprime)
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to convert delta G equation from lnQ to LogQ, multiply RT by ____
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-2.303
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R is the gas constant, values are____
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1.987 cal/mol K
8.134 j/mol K |
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How do you make a rxn with a (+) delta G proceed?
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Couple it with a favorable rxn (-) deltaG
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Energy Rich Compound
1. ATP has a _____ bond 2. creatine phosphate has a _____ bond 3. 1,3-bisphosphoglycerate has a ____ bond |
1. phosphoric acid anhydride
2. phosphoguanidine 3. phosphoric-carboxylic acid anhydride |
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Energy Rich Compound
1. acetyl phosphate has a ____ bond 2. cAMP has a ____ bond 3. phosphoenolpyruvate has a _____ bond 4. acetyl-coA has a _____ bond |
1. phosphoric-carboxylic acid anhydride
2. phosphoric acid anhydride 3. enol phosphate 4. thiol ester |
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Which high energy compound does not have a phosphate bond?
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acetyl-CoA
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Which enzyme converts 1,3-DPG to 3-phosphoglycerate?
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phosphoglycerate kinase
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Which enzyme converts phosphoenolpyruvate to pyruvate?
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pyruvate kinsase
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Which enzyme converts creatine to creatine phosphate?
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creatine kinase
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Which enzyme converts glucose to glucose-6-phosphate?
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hexokinase
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These two reactions cleave a phosphate group___and ____
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1,3 DPG -> 3-phosphoglycerate
phosphoenolpyruvate -> pyruvate |
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These two reactions add a phosphate group___and ____
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creatine ->creatine phosphate
glucose -> glucose-6-phosphate |
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Acetyl CoA exists in a ___ form which forms high energy thioester bonds with acyl groups
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reduced (CoASH)
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Three precursors to formation of acetyl CoA. What is the process called for each of the precursors?
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1. glycogen--glycogenolysis
2. triglyceride--lipolysis 3. protein--proteolysis |
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Pyruvate dehydrogenase: two cofactors
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1. TPP=thiamine pyrophosphate
2. SH-Lip-SH =lipoamide (with Sulfur-hydrogen) |
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equation for pyruvate dehydrogenase
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Pyruvate + NAD+ +CoASH -> acetyl CoA + NADH + H+ +CO2
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insulin ____ activity of pyruvate dehydrogenase and hormones ____ activity
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increase
decrease |
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____ and ____ are competitive inhibitors of the pyruvate dehydrogenase rxn
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Acetyl CoA
NADH |
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Pyruvate dehydrogenase is regulated by ____ by protein kinase and phophoprotein phosphatase
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covalent modification through phosphorylation
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Pyruvate dehydrogenase
____ and _____ activate protein kinase |
Acetyl CoA and NADH
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Pyruvate dehydrogenase
____ is a potent inhibitor of the kinase |
pyruvate
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Pyruvate dehydrogenase
____ is a potent activator of the phophoprotein phosphatase |
Ca 2+
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Mitochondrial ATP Synthesis
1. The substrate of the TCA cycle (citric acid cycle or Krebs cycle) is the _____ |
2 carbon unit of Acetyl CoA
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One complete turn of the TCA cycle yields_____
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2 CO2
1 GTP 3 NADH 1 FADH2 |
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___ NADH and ___ FADH2 are oxidized by the ETC to yield ___ ATP
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3
1 9 |
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___ and ____ can make acetyl CoA that can then enter the TCA cycle
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pyruvate, fatty acids
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1. glycogen -> glucose process
2. glucose -> pyruvate process 3. pyruvate ->acetyl CoA process |
1. glycogenolysis
2. glycolysis 3. oxidation |
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1. triglyceride -> free fatty acid process
2. free fatty acid -> acetyl CoA |
1. lipolysis
2. B-oxidation |
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1. protein -> amino acids process
2. amino acids -> Acetyl CoA process |
1. proteolysis
2. deamination and oxidation |
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pyruvate dehydogenase is active when ____ adds phosphate (step requires ___ and ___).
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phosphatase
Mg2+ Ca2+ |
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pyruvate dehydogenase is inactive when ____ cleaves ATP to form ADP (which requires ____)
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kinase
Mg2+ |
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when pyruvate is converted to acetyl CoA, ___, ___, and ____ are also formed
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NADH, H+, CO2
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What units regulate the TCA cycle?
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pyruvate and fatty acids because they make the Acetyl CoA to go into the cycle
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The TCA cycle is ____ ATP synthesis
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primary
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The first enzyme of the TCA cycle is ____ and it catalyzed the condensation of ____ and ____ (called ____ after as condensation is happening) that forms ____
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citrate synthase
acetyl CoA, oxaloacetate enzyme-bound citroyl-SCoA citrate |
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____ enzyme catalyzes the condensation of an acetyl group with the alpha-keto carbon of oaloacetate yielding citrate
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citrate synthase
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Citrate synthase rxn is exergonic (T/F)
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true
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concentration of oxaloacetate in the mitochondria is ____, well ____ the Km of the enzyme
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low
below |
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Conversion of citrate to isocitrate by aconitase is ___, but ____ is favored
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reversible
citrate |
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Aconitase positions an ___ next to the carboxyl group allowing oxidative decarboxylation
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-OH
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Isocitrate undergoes oxidative decarboxylation to yield _____.
This reaction is endergonic (T/F). |
alpha-ketoglutarate
False, exergonic |
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alpha-ketoglutarate uses ____ enzyme to form succinyl CoA, which converts CoASH to ____ and NAD+ to ____ and ____
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alpha-ketoglutarate dehydrogenase
CO2 NADH, H+ |
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alpha-ketoglutarate is a single peptide enzyme (T/F)
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False, multienzyme complex
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Alpha-ketoglutarate is analagous to _____
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pyruvate dehydrogenase
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Coenzymes for alpha-ketogluterate dehydrogenase
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thiamine pyrophosphate, lipoic acid, CoASH, FAD and NAD+
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alpha ketoglutarate dehydrogenase is exergone (T/F)
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True
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_____ is an energy rich-thiol ester similar to acetyl CoA
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succinyl CoA
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Succinyl CoA is converted to succinate by succinyl CoA synthetase using ___ and ___ (coupled to make it exergonic).
____ is a second product |
GDP
Pi CoASH |
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Succinate is converted to fumarate by oxidizing _____ to _____
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FAD
FADH2 |
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succinate dehydrogenase has 4 subunits containing FAD covalently attached to a ____ plus 1 subunit containing 3 _____
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histadine
iron sulfur centers (nonheme iron) |
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Electrons are transfered from succinate thru ____ to ____ centers that undergo oxidation/reduction. Electrons are eventually transferred to ____ in the ETC
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FAD
Fe-S Coenzyme Q |
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Coenzyme Q is also called ____
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ubiquinone
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1 Fumarate plus _____ are converted to L-Malate by the enzyme Fumarase.
2 Reaction is a ____ rxn. 3. Rxn is ______. 4. Enzyme is stereoselective for the ___ form of substrate |
1 water
2 hydration 3 freely reversible 4 trans |
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Malate dehydrogenase converts L-Malate to oxaloacetate and vice versa.
1 ____ is favored because the reaction is endergonic. 2 To make oxaloacetate, reducing equivalents must be trasfered to ___ to yield ___ and ___. |
1 malate
2 NAD+, NADH, H+ |
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Why is any oxaloacetate formed the the rxn is endergonic?
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1 citrate synthase removes all oxaloacetate, which pushes rxn foward
2 NADH + H+ is rapidly oxidized to NAD+, which furthur pulls rxn foward |
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1 In the TCA cycle, two carbon moeties are oxidized completely to ___ and ____
2 ___ reducing equavilents are produced (____, ____, and ___) |
1 CO2, H2O
2 4 (3 NADH, H+, FADH2) |
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TCA
oxidation of each NADH + H+ = ____ ATP |
2.5
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TCA
oxidaiton of FADH2 formed in succinate dehydrogenase rxn = ___ ATP |
1.5
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GTP formed in succinyl-CoA synthetase will convert to ___ ATP
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1
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One turn of the TCA cycle yields ____ ATP
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10
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In the TCA cycle, ___ and ___ have to be reoxidized or respiration will fall
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NADH, FADH2
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TCA internediates serve as precursors for ___, ___, and ____
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amino acid, fatty acid,and glucose synthesis
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TCA
1 citrate can be used for ____ synthesis 2 alpha ketoglutarate can be used for ____ synthesis, which can then be used for _____ synthesis |
1 fatty acid and sterol
2 amino acid, neurotransmitters |
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TCA
1 succinyl CoA can be used for ____ synthesis 2 malate can be used for ____ 3 oxaloacetate can be used for ____ synthesis |
1 heme
2 gluconeogenesis 3 amino acid |
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3 most regulated enzymes in TCA cycle:
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1 citrate synthase
2 alpha-ketoglutarate dehydrogenase 3 isocitrate dehydrogenase |
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____ drives the TCA cycle
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oxygen
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gluconeogenesis
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produces glucose
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glycolysis
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breaks down glucose
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change in CO2 amount coming out of TCA has effect on TCA cycle (T/F)
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true
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____ and ___ are electron carriers in the TCA cycle
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NADH, FADH2
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TCA
higher ATP/ADP ratio correlates to decreased _______, and the TCA cycle ____ |
NADH, FADH2
is inhibited |
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What is the commitment step in TCA?
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pyruvate dehydrogenase
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3 steps of TCA that produce reducing equivalents
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1. 2 decarboxylation steps
2. succinate ->fumerate 3. malate ->oxaloacetate |
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____form pyruvate, which can be made into____ or ____ to enter the TCA cycle
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amino acids, oxaloacetate, acetyl CoA
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1 amino acid (______) can be made into oxaloacetate
2 amino acid (______) can be made into alpha-ketoglutarate 3. amino acids can also be made into _____ to enter the TCA 4. ____ and ____ amino acids make propionyl CoA that is made into succinyl CoA to enter TCA |
1 aspartate
2 glutamate 3 fumarate 4 valine and isoleucine |
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Depletion of _____ by other biosynthetic pathways impacts TCA function
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TCA intermediates
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1 Functional TCA requires source of _____.
2 Rxns that suppy that and also ____ are termed ____ rxns. 3 The most important is ______. |
1 4-carbon atoms
2 5 carbon atoms, anaplerotic (filling up) 3 pyruvate carboxylase |
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____ in TCA is inhibited by ATP, NADH, succinyl CoA, long chain acyl CoA derivatives
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citrate synthase
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isocitrate dehydrogenase is stimulated by ____ and inhibited by ___ and ____
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ADP
ATP NADH |
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_____ is inhibited by ATP, GTP, NADH and Succinyl CoA. It is activated by Ca 2+
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Alpha-ketoglutarate dehydrogenase
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citrate synthase in TCA is inhibited by:______
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ATP, NADH, succinyl CoA, long chain acyl CoA derivatives
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_____ is stimulated by ADP and inhibited by ATP and NADH
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isocitrate dehydrogenase
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Alpha-ketoglutarate dehydrogenase is inhibited by _____ . It is inactivated by ____
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ATP, GTP, NADH, succinyl CoA
Ca2+ |
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The inner mitochondrial membrane is ____% protein, rich in ____ fatty acids, and has a high concentration of _____
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80
unsaturated cardiolipin |
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The inner mitochondrial membrane is where ____ and___ take place
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ETC
oxidative phosphorylation |
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1 all of the enzymes for metabolism (except 4) in the mitochondria are located in the ____
2 What are the 4 exceptions, and where are they located? |
1 matrix
2 1. succinate dehydrogenase 2. fatty acid oxidation enzymes 3. porforin synthesis enzymes (some) 4. urea synthesis enzymes (some) located in or on the inner mitochondrial membrane |
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The outer mitochondrial membrane is rich in _____, ____% lipid, _____% protein
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porin
30-40 20-70 |
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Green sphere in the picture of the mitochondria are _____
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F1 portions of ATP synthase
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cristae
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invagination of the inner membrane increasing surface area
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Molecules up to ____ KD can move in and out of the inner mitochondrial membrane
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10,000
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Electron donor =
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reducant
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Electron acceptor =
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oxidant
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redox rxn =
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transfer of electrons from one chemical species to another
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electrochemical half cell
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oxidized plus the reduced form of each chemical species
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_____ with one common ____ comprise a redox rxn
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two half cells, intermediate
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coupled half cell reactions can drive ____ reactions in the same way that thermodynamically coupled reactions do
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energetically unfavorable
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redox potential
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how easy an electron donor will give up electrons
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redox potential can be determined by measuring the electromotive force generated by a half cell with respect to to a ____
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standard reference half cell
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what is the standard reference half cell? defined as ___ volts?
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H+ + E- -> 1/2 H2
defined as 0 volts |
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negative redox potential
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compound has lower e- affinity than H2
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positive redox potential
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compound has higher e- affinity than H2
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____ strong reducing agent,
____ strong oxidizing agent |
NADH
O2 |
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Is the redox reaction concentration dependent?
|
yes
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Nernst equation
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E=Eo' + 2.3 RTnF log ([oxidant]/reductant])
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Using the nernst equation, if the [oxidant] goes up, E _____
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goes up
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Using the nernst equation, if the [reducant] goes up, E _____
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goes down
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Nernst equation
E is observed potential when all reactant are at ____ |
1M
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Nernst equation
Eo' is the standard potential at pH ___ |
7
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Nernst equation
R is the ____ (____) |
gas constant
8.3 J/Kmol |
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Nernst equation
T is measured in ____ |
Kelvin
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Nernst equation
n = ___ |
number of transferred electrons
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Nernst equation
F=______ (_____) |
faraday constant
96,500 J/Vmol |
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The calculated ATP from NADH and FADH2 is what?
The actual value is what? |
3 mol ATP/1 mol NADH
2 mol ATP/1 mol FADH2 2.5 mol ATP/1 mol NADH 1.5 mol ATP/1 mol FADH2 |
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Which complex is the most complicated?
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Complex I
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The MW of complex I is ____
|
1 million daltons
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Reske-Fe-S center is a ____ protein that is part of the mitochondrial ____
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trans-membrane
ETC |
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If the oxidation potential is highly (+) it will likely
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be reduced (accept electrons)
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If the oxidation potential is highly (-) it will likely
|
be oxidized (donate electrons)
|
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_____ catalyzes transfer of electrons to ubiquinone
|
NADH-ubiquinone oxidoreductase
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Where does the ETC occur?
|
between the matrix and intermembrane space
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In complex I, the electrons go to the ____
|
Fe-S centers
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Complex I results in the overall oxidation of NADH and transfer of two electrons to _____
|
Ubiquinone (Coenzyme Q)
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Equation of Complex I
|
NADH + H+ + FMN -> NAD+ + FMNH2
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In Complex I, NADH is in the ____ side, and it reduces FMN, which then reduces ____ that then reduce(___), which is a specific Fe-S cluster, which then transfer electrons to ubiquinone
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matrix
Fe-S N2 |
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Ubiquinone can accept and transfer ___ or ___ electrons due to the ____
|
one
two semiquinone |
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______ makes CoQ lipid soluble for shuttling electrons b/w complexes I and II
|
hydrophobic isoprene (oxidized coenzyme Q)
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What are the three forms of coenzyme Q? Is conversion between structures reversible?
|
oxidized Coenzyme Q
semiquinone form reduced Coenzyme Q yes |
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Ubiquinone reduction is by all _____and includes ____, _____, _____, and _____
|
flavoprotein dehydrogenases
Complex I Complex II (succinate DH) Glycerol-3-Pi DH Electron transferring flavoprotein-ubiquinone oxidoreductase |
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Complex II consists of: ____, which reduces ____, which reduces ____, which reduces _____
|
Succinate, FAD, FeS, UQ
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How many protons are pumped out of Complex I?
|
4
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The enzyme in complex II is ____, which has 2 subunits. Subunit 1 is ___KD and has ___ covalently bound to _____. Subunit 2 is ____KD and has ___Fe-S centers and 2 small ____
|
succinate dehydrogenase
70 histadine 3 hydrophobic subunits |
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cytochrome B has ___ hemes and cytochrome C has _____ heme
|
2
1 |
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Complex III has ____ subunits with ____ prosthetic groups that act as redox centers
|
11
3 |
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Complex III
Membrane anchoring domain contains ____ plus ____ protein |
heme
Fe-S |
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Complex III
transmembrane domain contains ____ heme plus ____ protein |
2
Fe-S |
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Part of Complex III extends into the _____
|
mitochondrial matrix
|
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How are cytochrome hemes different from hemoglobin heme?
|
they undergo oxidation-reduction reactions
|
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The part of complex III that extends into the matrix has a lot of ____
|
alpha helices
|
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What is the enzyme in Complex III?
|
cytrochrome c oxidoreductase
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Cytochromes c and b are in complex ____
|
III
|
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Cytochrome B contains two heme groups: a ____ heme and a ____ heme
|
high potential +.5 V
low potential -.1 V |
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cytochrome c contains one ____ heme
|
type c
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Complex III
Q-cycle mechanism accounts for transfer of ___ protons across per two electrons transferred from ___ to cytochrome c |
4
ubiquinol |
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Complex III
____protons are taken up on the matrix side of the inner membrane to reduce the ______ |
2
ubiquinone |
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Complex III
____ protons are released on the ____ side of the membrane during the transfer of 2 e- to the Fe-S proteins and cytochrome ____ |
4
cytosilic c1 |
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Cytochrome A has heme ___ and Iron ____ and Proforin ____ with formal groups and an isoprenoid side chain, which makes it variation of the basic structure
|
A
A 9 |
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Cytochrome B has the same Fe complex as ____ and ____ but it is buried so far in the membrane that it can't bind O2
|
hemoglobin
myoglobin |
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cytochrome c has heme covalently bound to two ___ residues and is a mobile electron carrier
|
cysteine
|
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|
cytosolic fluid is everything except ___ and ____
|
organelles
insoluble compounds |
|
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Each complex exists independently in the mitochondrial matrix (T/F)
|
true
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Complex I is inhibited by what?
|
Rotenone
Amytal |
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Complex III is inhibited by what?
|
antimycin A
myxothiazol stigmatellin |
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Complex IV is inhibited by what?
|
carbon monoxide
sodium azide potassium cyanide |
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____ can be used to reduce cytochrome c in the presence of tetramethylene phenylene diamine
|
ascorbate
|
|
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Complex IV has cytochrome ____
|
a1a3 (Cu)
|
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What are the 3 TCA byproducts that produce NADH?
What non-TCA product produces NADH? |
Malate
alpha-ketoglutarate isocitrate pyruvate |
|
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What TCA byproduct is used in Complex II?
|
succinate
|
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_____ contains FAD and is used to transfer one or two electrons to coenzyme Q in b/w Complex I and Complex II
|
alpha-glycerol phosphate
|
|
|
___ and ____ are fatty acid and ketone bodies that are oxidized to form NADH, which reduces FMN in Complex I
|
B-hydroxybutyrate
B-hydroxyacl CoA |
|
|
____ is a fatty acid and ketone bodies that is oxidized to form FAD, which can reduce Coenzyme Q in b/w Complex I and Complex II
|
fatty acyl CoA
|
|
|
Overall reaction is ____ +____ in a reversible step into cytochrome a1a3, which forms ____
|
1/2 O2
2H+ H2O |
|
|
The Kreb's cycle takes place in the ____
|
mitochondrial matrix
|
|
|
Complexes ___ and ___ work to reduce UQ?
|
I, II
|
|
|
Complex III has a cytochrome ____ complex, what special Fe-S centers are in this complex?
|
bc1
Rieske |
|
|
What complex has Cu?
|
Complex IV
|
|
|
Which complex has 2 b-type hemes?
Which complex has 2 a-type hemes? Which other complex has b-type hemes? |
III
IV II |
|
|
There is phosphorylation in the ETC (T/F)
|
true
|
|
|
Complex I
The first step in the ETC is the oxidation of ____ to ____, the electrons are transferred to ___, producing ____ |
NADH
NAD+ FMN FMNH2 |
|
|
Complex I
The reduced FMNH2 is oxidized back to FMN by transferring the electrons to an _____ |
Fe-S center
|
|
|
Complex I
Electrons are transferred to a tightly-bound ______ molecule, reducing it to form _____ |
coenzyme Q
ubiquinol |
|
|
Complex I
The electrons from bound ubiquinol are tranferred to moblie ______ located in the inner Mito Matrix. These molecules can then shuttle around in the membrane to pass the e- to another protein complex. Net result is ____ protons pumped out of the matrix and into the intermembrane space for each molecule of ____ which is oxidized. |
ubiquinone
4 NADH |
|
|
Complex II
electrons are passed through an Fe-S center before being transferred to moble ubiquinone in the _____ |
mitochondrial membrane
|
|
|
Complex III
the first half of this rxn is the migration of ubiquinol to the Qp site of ______. ____e- and ____ protons are released, resulting in an oxidation to a ____, which can leave the site and enter the membrane pool |
cytochrome c reductase
2 2 ubiquinone |
|
|
Complex III
one electron is passed to mobile ____ in the intermembrane space. the other electron is passed to a _____ in the Qn site of the enzyme |
cytochrome c
semiquinone intermediate |
|
|
Complex III
A second CoQ enters QP site and is oxidized. What is different from the first time this happened? |
the second e- reduces semiquinone to ubiquinol returning it to the membrane pool.
|
|
|
Complex III
Net result: ____ protons are pumped out of the matrix for each molecule of ubiquinol which is oxidized. The purpose is to transfer the two electrons from _____ to two molecules of the one-electron carrier, ______ |
4
ubiquinol cytochrome c. |
|
|
after cytochrome c is reduced in complex ____, it is oxidized by complex ____, in a process which results in _____ protons being pumped out of the mito matrix
|
III
IV 2 |
|
|
what enzyme oxidizes cytochrome c in complex IV?
|
cytochrome c oxidase
|
|
|
Complex IV
two molecules of the reduced form of cytochrome c pass their electrons to a ______ complex and then to a ____ group. This last group is responsible for the reduction of oxygen to produce water in a multi-step rxn which uses ____ e- and ____ protons for each molecules of oxygen that is reduced. |
copper-heme a
copper-heme a3 4 4 |
|
|
electron transport through Complex III is also known as the ____
|
Q cycle
|
|
|
is the copper-heme a and the copper-heme a3 far away from each other?
|
No, 1.5 angstroms apart, this gives rapid transport
|
|
|
_____ allows protons back into the matrix and produces ___ in the process
|
ATP synthase
ATP |
|
|
What two ways do protons being pumped across a membrane develop potential energy?
|
separation of charge
pH gradient |
|
|
Alternate name for ATP synthase
|
F1/F0 ATPase
|
|
|
What is F0?
|
channel through membrane in ATP synthase
|
|
|
Terminal oxidation and oxidative phosphorylation gives ___ ATP
|
3
|
|
|
NAD and FAD are ____ in the TCA, which allows them to be ____ in the ETC, which gives energy to make ____
|
reduced
oxidized ATP |
|
|
Electrons move through the membrane in the ETC (T/F)
|
false, only protons move through the membrane
|
|
|
____ is transported from the cytosol into the matrix in exchange for an ____ transported from the matrix to the cytosol. This is happening by a ____, which follows Michaelis/Menton Kinetics
|
ADP
ATP Adenine nucleotide translocator |
|
|
Phosphate utilizes the ___ to be transported from the cytosol to the matrix. This is happening by a ____
|
proton gradient
phosphate translocator |
|
|
How are reducing equivalents shuttled across the mito inner membrane?
|
Malate-Aspartate shuttle
aspartate-glutamate transporter malate-alpha-ketoglutarate transporter |
|
|
Exogenous glycogen is hydrolyzed to glucose in the GI tract, most is absorbed into the ____vein, then into general circulation to be used by other tissues. Glucose is first exposed to the ____, if the concentration of blood glucose is high it will be removed for _____, if low, it will undergo _____
|
portal
liver glycolysis glycogenesis |
|
|
____ is the first organ exposed to blood back from the pancreas, and has the highest concentration of glucogon and insulin, which is important in hormonal regulators of blood glucose
|
liver
|
|
|
glycogen
|
stored glucose in animals
|
|
|
some cells only use glucose as fuel (T/F)
|
true, some specialized cells
|
|
|
Respiration
|
oxidation of organic fuels by molecular oxygen. oxygen is the final electron acceptor
|
|
|
anaerobic fermentation
|
oxidation-reduction rxn in the absense of oxygen
|
|
|
Overall Rxn of glycolysis
|
glucose + 2Pi +2ADP -> 2 lactic acid + 2 ATP + 2 H2O
|
|
|
alcohol fermentation
|
glucose + 2Pi + 2ADP -> 2 ethanol + 2CO2 + 2ATP + 2H2O
|
|
|
Glucose is transported into the RBC by ____. ____ traps the glucose in the cell.
|
GLUT1
phosphorylation |
|
|
gluconeogenesis requires ATP (T/F)
|
true
|
|
|
some enzymes in glucose metabolism and gluconeogenesis are the same (T/F)
|
true
|
|
|
Preparatory pathway for aerobic metabolism is known as ______
|
glycolytic pathway
|
|
|
Liver stores glycogen for maintenance of ____ levels for the brain
|
blood/glucose
|
|
|
glucose -> glucose 6-p what enzyme?
|
hexokinase
|
|
|
glucose 6-p -> lactate what process?
|
glycolysis
|
|
|
glucose 6-p -> NADPH what intermediates?
|
pentose phosphates
|
|
|
What enzyme turns pyruvate into acetyl CoA? In what organ does glycolysis produce pyruvate, which releases CO2 and produces CoA to enter the TCA cycle (which releases more CO2)
|
pyruvate decarboxylase
brain |
|
|
In the RBC's glycolysis produces lactate. ___ is a byproduct that is converted into water when 2GSH goes to GSSG.
|
H2O2
|
|
|
Glucose metabolism in the brain is insulin independent (T/F)
|
true
|
|
|
Glucose metabolism in adipose tissue involves GLUT___. Glucose 6-P is converted to glycogen by _____. Glycogen is converted to Glucose 6-P by ______. Glucose 6-P can be converted to pentose phosphates. Pyruvate is converted to acetyl CoA, which is converted to fat by _____
|
4
glycogenesis glycogenolysis lipogenesis |
|
|
GLUT4 exists in membrane vesicles located within the _____ of the cells. Binding of insulin to its receptor on the _____ initiates a signaling cascade that promotes fusion of the cytosolic vesicles which deposits GLUT-4 in the plasma membrane for glucose transport. Occurs in ____ , ____and _____
|
cytosol
plasma membrane adipose tissue muscle heart |
|
|
Glucose metabolism in the liver involves GLUT___. Glucose 6-P is converted to glycogen and vice versa. Glucose 6-P can be converted to_____ or_____ . conversion to pyruvate is reversible (_____ in other tissues). pyruvate can be converted to lactate or acetyl CoA, which can then be converted to fat.
|
2
pentose phosphates glucuronides unlike |
|
|
Glut2 is insulin dependent (T/F)
|
false, insulin independent
|
|
|
Glut 2 is an insulin independent, ____ affinity, ____ capacity glucose transporters
|
low
high |
|
|
The ____ pathway is for the production of NADPH
|
pentose phosphate
|
|
|
The glucuronic pathway is for ____ and ____ detox, this occurs in the ____
|
drug
billirubin liver |
|
|
Synthesis of fat is by ___ and ___
|
glycolysis
TCA |
|
|
In the liver, conversion of pyruvate to glucose 6-P is by the process ____ and uses ____ precursors
|
gluconeogensis
2 carbon |
|
|
gluconeogenesis
|
process in liver of converting pyruvate to glucose 6-P
|
|
|
glycogenesis
|
process of converting glucose 6-P to glycogen
|
|
|
glycogenolysis
|
process of converting glycogen to glucose 6-P
|
|
|
what organ has the greatest number of ways to metabolize glucose?
|
liver
|
|
|
What are the 4 types of reactions in the glycolytic pathway? Which are reversible?
|
phosphoryl transfer
phosphoryl shift aldol cleavage dehydration All are reversible |
|
|
What is the priming stage in glycolysis?
|
input of 2 ATP to convert glucose into fructose-1,6-biphosphate
|
|
|
What is the most important regulatory enzyme of glycolysis?
|
phosphofructose-1-kinase
|
|
|
What is the commitment step in glycolysis?
|
conversion of fructose-6-phosphate to fructose-1,6-phophate (by phosphofructose-1-kinase)
|
|
|
reversible reactions of glycolysis are shared by ____ and ____
|
gluconeogenesis
glycogenolysis |
|
|
The priming stage of glycolysis:
_______->_________->_________-> _______ |
glucose
glucose 6-phosphate fructose 6-phosphate fructose-1,6-phosphate |
|
|
conversion of glucose to glucose-6-phosphate is by ____(and requires____) and is ____
|
hexokinase
ATP irreversible |
|
|
All glycolytic enzymes are in the ____
|
cytosol
|
|
|
Step 2 of glycolysis: fructose 1-6-bisphosphate aldolase catalyzes the cleavage of cyclic or linear form into ___ and ____
|
dihydroxyacetone
glyceraldehyde-3-phosphate |
|
|
Is step 2 of glycolysis reversible? Do the products convert with each other reversibly?
|
yes
yes |
|
|
Stage 3 of glycolysis involves ____ and ____. Phosphoglycerate kinase uses _______, Before this point net ATP is _____ Pyruvate kinase reaction is ______.
|
oxidoreduction reactions
synthesis of ATP zero substrate level phosphorylation irreversible |
|
|
What starts stage 1 of glycolysis? what ends stage 1?
|
glucose
fructose-1,6-phosphate |
|
|
What starts stage 2 of glycolysis? what ends stage 2?
|
fructose-1,6-phosphate
glyceradlehyde-3-phosphate (GAP) |
|
|
What starts stage 3 of glycolysis? what ends stage 3?
|
glyceraldehyde 3-Pi-DH
pyruvate (which can convert to lactate reversibly) |
|
|
stage 3 of glycolysis has enzyme _____ that converts pyruvate to lactate, is this the only rxn in the body that produces lactate?
|
lactate dehydrogenase
yes |
|
|
In Stage 3 of glycolysis, the enzyme, __1___ catalyzes 2 exergonic reactions:__2__ and _3___, and one endergonic reaction, __4___. The net delta G prime is ____5_, which indicates a ___6___
|
1 Glyceraldehyde-3-phosphate
2 aldehyde oxidized to carboxyl 3 NAD+ reduced to NADH 4 formation of a mixed anhydride 5 b/w the carboxylic acid and phosphoric acid 5 endergonic (1.5 kcal/mol) 6 freely reversible rxn |
|
|
This pathway is small but efficient, and is used when energy is needed quickly. Is it reversible?
|
2,3-bisphosphatoglycerate shunt
no |
|
|
in the 2,3-bisphosphatoglycerate shunt, ____ glucose is converted to ____biphosphoglycerate, which is convereted to ____ biphosphoglycerate by 2,3-BPG mutase. The product is converted to 3 phosphoglycerate by _____, and ____ is released. 3 phosphoglycerate is converted to ____, which is then converted to _____
|
1/2
1,3 2,3 2,3-BPG phosphatase Pi 2-phosphoglycerate lactate |
|
|
Which is more efficient? glycolysis or 2,3-biphophoglycerate shunt?
|
2,3-biphophoglycerate shunt
|
|
|
___ to ____% of RBC glucose is converted to lactate thru BPG shunt
|
15-25
|
|
|
If the body has sufficient energy glycolysis stops at step 3 (T/F)
|
true
|
|
|
The priming step in glycolysis makes ATP (t/f)
|
false, it consumes ATP
|
|
|
Glycolysis makes overall ____ ATP
|
2
|
|
|
3 reasons why we store glucose as glycogen?
|
1. Fat cannot be metabolized as fast as glycogen
2. Fat cannot be used as an E source in the absence of O2 3. Fat cannot be converted to glucose to maintain blood glucose levels needed by brain |
|
|
All steps of pathways of glycolysis are reversible (T/F)
|
False, but MOST have reversible steps
|
|
|
All steps of pathways of glycolysis form intermediates and use intermediates (T/F)
|
true
|
|
|
All steps of pathways of glycolysis if you change one thing you change all things (T/F)
|
true
|
|
|
All steps of pathways of glycolysis feed into the TCA (T/F)
|
true
|
|
|
All steps of pathways of glycolysis interact (T/F)
|
true
|
|
|
Regulation of enzymes occurs by limiting turnover rate from different isoforms (t/f)
|
true
|
|
|
enzymes are thought to be regulated by compartmentation (t/f)
|
true
|
|
|
catalytic sites on enzymes flicker b/w having a subrstrate and a product binding site (t/f)
|
true
|
|
|
how does product inhibition work?
|
excess product "ties up" the enzyme in one state and slows catalysis
|
|
|
Allosteric activation is more helpful at vmax (t/f)
|
false, less helpful
|
|
|
highly regulated enzymes can have both allosteric activator and inhibitor sites (t/f)
|
true
|
|
|
allosteric activator and inhibitor sites can overlap (t/f)
|
true (but rare)
|
|
|
What is an example of allosteric activator and inhibitor sites overlapping?
|
phosphofuctokinase-1
|
|
|
What is an example of product inhibition?
|
hexokinase
|
|
|
In metabolic pathways, regulation can occur at enzyme-limited or substrate-limited sites (t/f)
|
false, only at enzyme-limited sites
|
|
|
enzyme-limited reactions are far from equilibrium (t/f) and the substrate accumulates (t/f)
|
true
true |
|
|
substrate-limited reactions are far from equilibrium (t/f) and the substrate is quickly metabolized so it does not accumulate (t/f)
|
false, at or near equil
true |
|
|
Lipitor changes cholesterol metabolism (t/f)
|
true
|
|
|
Which 3 steps in a pathway are the ones you would want to regulate?
|
1. entry to the pathway (the committed step)
2. exit from a pathway 3. entry/exit points within one pathway that go to or come from another pathway |
|
|
Steps you would want to regulate in a pathway, give an example of each, then tell which step is the most difficult but most efficient, then tell which step is the easiest
1. entry to the pathway (the committed step) 2. exit from a pathway 3. entry/exit points within one pathway that go to or come from another pathway |
1. 6-phosphofructo-1-kinase
2. pyruvate kinase 3. hexokinase step 3 step 1 |
|
|
Glucose transporters transport by _____, is this reversible? why or why not?
|
facilitated diffusion (carrier-mediated diffusion)
not reversible in life because glucose is constantly being metabolized and rapid phosphorylation prevents leakage out |
|
|
In most tissues, ____ is responsible for phosphorylation of glucose
|
hexokinase
|
|
|
hexokinase is inhibited by _____, which is the _____ of the first reaction of glycolysis. As a result, ___ and ___ are not committed to glycolysis unless necessary
|
glucose-6-phosphate
product glucose, ATP |
|
|
The primary site of regulation in glycolysis is at the enzyme ____
|
phosphofructokinsase-1
|
|
|
PFK-1 is allosterically inhibited by ____ and ____ and allosterically activated by ____, ___, ____, and ___
|
ATP, citrate
AMP, ADP, Fructose-2,6-phosphate |
|
|
Is glucose-6-phosphate ->fructose-1,6-bisphosphate reversible?
|
no
|
|
|
Fructose-2,6-phosphate is a positive allosteric activator of PFK1 (glucose 6-phosphate to fructorse 1,6-bisphosphate). F-2,6,Pi is formed from adding a ____ group to fructose-6-phosphate, and converted back to this by removing a ____ group
|
phosphate
phosphate |
|
|
Glucagon inhibition of hepatic glycolysis is mediated through the ____ cascade, which signals activation of ____ and inhibition of ____. If cAMP goes up, glycolysis ____
|
cAMP
phosphatase kinase goes down |
|
|
pyruvate kinase catalyzes the last step of glycolysis. The inhibitors are ___, ____, and ____. The activator is _____
|
ATP, alanine, acetyl-CoA
fructose-1,6-bisphosphate |
|
|
Muscle stores ____% weight as glycogen. ____ in liver. Which has more glycogen in the body?
|
1-2
10% muscle (twice that of liver) |
|
|
glycogen
|
polymer of glucose used as a energy storage molecule in the liver and muscle
|
|
|
in the muscle, glycogen is a fuel reserve for ____ within that tissue
|
ATP
|
|
|
In the liver, glycogen is a fuel reserve to maintain ____ concentrations
|
blood/glucose
|
|
|
Red muscle fibers are ____, they have ___blood flow, large amounts of ____, packed with _____, glucose completely oxidized to __ and ___
|
slow
rich myoglobin mitochondria CO2, H20 |
|
|
white muscle fibers are ____, ___ myoglobin, ____ mitochondria, glucose metabolism yields ____ as end product, can only function at full capacity for short periods of time
|
fast
less fewer lactate |
|
|
What does glycogen phosphorylase do?
|
knocks off 1 glucose each time
|
|
|
what does phosphoglucomutase do?
|
converts glucose-1-phosphate to glucose-6-phosphate
|
|
|
what does glucose-6-phosphatase do?
|
convert glucose-6-phosphate to glucose plus inorganic phosphate
|
|
|
glucose-6-phosphatase cleaves at ____ end of glucose molecule
|
terminal nonreducing end
|
|
|
How is glucose degradation different in the liver vs peripheral tissue?
|
glycogenolysis occurs in the liver and then stops (ATP is neither produced nor used when glucose removed from glycogen), in the peripheral tissue, glycolysis occurs after glycogenolysis, glucose-6-phosphate is degraded to yield lactate (glycolysis) in white muscles and CO2 in red muscle (glycolysis then TCA).
|
|
|
glycogen phosphorylase reaction that removes one glucose from glycogen is called ____
|
glycogenolysis
|
|
|
glucose 6-phosphate reaction to glucose is called ____
|
gluconeogenesis
|
|
|
glycogenolysis then glycolysis (which happens in peripheral tissue) gives the net reaction:
|
(glucose)n + 3ADP +3Pi +H+ -> (glucose)n-1 + 3ATP + 2 H2O
|
|
|
There are two types of glycogen debranching enzymes: the one that makes a branch longer by moving pieces is a _____, the one that makes a branch shorter by removing glucose is a _____
|
transferase
glucosidase |
|
|
why is glycogen branched?
|
to remove glucose quickly
|
|
|
How many units must the main chain of glycogen have? Each branch must be ___ units from any other branch
|
11
4 |
|
|
Glucose-1-phosphatase is a unique reaction yielding an unactivated ____ glucose. The rxn is made energetically favorable through the hydrolysis of the ____ by _____. This reaction is part of _____
|
UDP
pyrophosphate pyrophosphatase glycogenesis |
|
|
UDP-glucose adds glucose to glycogen with the enzyme _____, which releases UDP. The bond formed with glycogen is called a ____
|
glycogen synthase
glycosidic bond |
|
|
The ___ end of glucose is always added to a ___ end of glycogen
|
reducing
non-reducing |
|
|
how is UTP made from UDP?
|
using ATP and nucleoside diphosphate kinase
|
|
|
Glycogen synthase produces ____ glycosidic linkages yielding linear chains of glycogen (_____)
|
alpha 1,4
amylose |
|
|
once 11 residues have been formed in a glycogen branch, ____ branching enzyme removes ___ residues and transfers them to another chain via an _____ glycosidic linkage. Why?
|
1,4-alpha-glucan
7 alpha-1,6 Gives more available ends of glucose to be activated |
|
|
What is the primer for glycogen synthesis?_____
It is a _____enzyme that uses _____ to link glucose to a _____ residue (the residue is on the primer) |
glycogenin
self glucosylating UDP-glucose tyrosine |
|
|
to achieve glycogenesis, glucose must be active (t/f)
|
true
|
|
|
Glycogen limits its own synthesis by inhibition of _____
|
glycogen synthase
|
|
|
glycogen phosphorylase degrades glycogen, the allosteric activator is ___, and the allosteric inhibitors are ___ and ____
|
AMP
ATP, Glucose |
|
|
hormones that increase cAMP (___ and ___ are examples) promote activation of glycogen phosphorylase by signaling activation of _____ and inactivating ______.
|
glucagon, epinephrine
phosphorylase kinase phosophoprotein phosphatase |
|
|
The advantage of regulation by a cAMP cascade: activation of _____ by one molecule of epinephrine causes formation of many molecules of cAMP. Each cAMP molecule activates a ____ which in turn activates many molecules of ____ and inhibits many molecules of _____
|
adenylyl cyclase
protein kinase A phosphorylase kinase phosphoprotein phosphatase |
|
|
glycogen synthase can by phosphorylated by ___ serine residues by ____ protein kinases
|
9
11 |
|
|
_____converts glycogen synthase from the active form (a) to the inactive form (b). The active from is the ___ form and is G-6-P ______, the inactive form is the ____ form and is G-6-P _____
|
phosphorylation
I independent D dependent |
|
|
glycogen degradation is increased by activation in cAMP because phosphylase kinases promote glycogen synthase to become ____ and phosphoprotein phosphatase promotes glycogen synthase to become _______
|
inactive
active |
|
|
Phosphorylation of glycogen synthase coverts the enzyme from ___ to ____
|
active
inactive |
|
|
Insulin promotes ____ of glycogen synthase
|
activation
|
|
|
phosphylated glucose will come out of the liver (t/f)
|
false, it will not come out
|
|
|
____ and _____stimulates glycogenolysis in liver, heart, and skeletal
|
glucagon, epinephrine
|
|
|
____ stimulates glycogenesis in muscle and liver
|
insulin
|
|
|
Epiniphrine increases ___ in tissues for flight or fight
|
glucose
|
|
|
Glycogenolysis regulation is by G-coupled protein, _____, which creates ____ that causes the release of _____, which stimulates glycogenolysis. The agonist is an ____ agonist.
|
phospholipase C
IP3 (inositol triphosphate) Ca alpha (receptor is alpha-adrenergic receptor) |
|
|
gluconeogenesis
|
synthesis or formation of glucose from fructose
|
|
|
glycogenesis
|
formation of glucose-6-phosphate from glycogen
|
|
|
inhibiting fructose-2,6-phosphate slows down conversion of fructose-6-phosphate to _____ (F-2,6,Pi is an activator of the enzyme)
|
fructose 1,6-bisphosphate
|
|
|
____ inhibits hepatic glycolysis in a G-couple protein reaction by binding to the receptor. Adnylyl cyclase is activated and cAMP is made that decreases _____, which inhibits _____
|
glucagon
Fructose-2,6-P glycolysis |
|
|
two compounds inhibit glycolysis, ___ and ____
|
glucagon, epinephrine
|
|
|
6-PF-2-K (6-phosphofructae-2-kinase) is regulated by _____by _____ and _____ enzymes. The modification is by _____. This step is found in ____
|
covalent modification
protein kinase A phosphoprotein phosphatase phosphorylation glycolysis |
|
|
Epinephrine ____glysolysis in the heart
|
accelerates
|
|
|
kinase and phosphatase enzyme lengths are different in the heart and liver (t/f)
|
true
|
|
|
gluconeogenesis has a main pathway of ___ ->____->____->____
|
pyruvate
oxaloacetate triose phosphates glucose |
|
|
pyruvate is made by ____ and____
oxaloacetate is made by ____ and ___ triose phosphates are made by __ and ____ glucose is made by _____ |
lactate, AA's
AA's, propionate glycerol, fructose galactose |
|
|
the cori cycle depends on ____, the alanine cycle is regulated by amount of ___ needed
|
diffusion
glucose |
|
|
The cori cycle is an inter-organ conversion of ____ released by ____ after excursion, which is converted to glucose and secreted to blood by the ____
|
lactate
skeletal muscle liver |
|
|
The alanine cycle in the liver requires ____ ATP and removes ____ NH2. ___ ATP is produced in the muscle cell. Is O2 required?
|
10
2 3-5 yes |
|
|
the Cori and alanine cycles are only functional in tissues that do not completely oxidize to CO2 and H2O (t/f)
|
true
|
|
|
The cori cycle occurs in the liver and ____, ___ ATP is consumed and ____ ATP is made
|
RBC
6 2 |
|
|
In the cori cycle, lactate and glucose enter cells by simple diffusion (t/f)
|
true
|
|
|
Both the cori and alanine cycle provide a continuous supply of glucose as a primary energy source (t/f)
|
true
|
|
|
The cori cycle is also called the ____ cycle, the alanine cycle is also called the ____ cycle
|
glucose lactate
glucose alanine |
|
|
The peripheral tissues releases ____ and the cori cycle and ___ in the alanine cycle
|
lactate
alanine |
|
|
Alanine cycle
NADH generated by glycolysis is not used to reduce pyruvate to lactate (t/f) |
true
|
|
|
Alanine cycle
NADH reducing equivalents are shuttled into mitochondria yielding ____ATP |
5-7
|
|
|
Alanine cycle
produces ____ that is removed by urea cycle but requires addl ATP |
NH4+
|
|
|
Which cycle is more efficient? Cori or alanine
|
alanine
|
|
|
Why is E consumed in the liver?
|
to generate storage of E in other tissue
|
|
|
lactate is converted to pyruvate by _____. Reaction is: ___+___->___+___+____+___
|
lactate dehydrogenase
2-L-lactate + 6ATP -> glucose + 6ADP + 6Pi + 4H+ |
|
|
PEP carboxykinase, pyruvate carboxylase, glucose-6-phosphatase, and fructose-1,60bisphosphatase are only in gluconeogenesis and not glycolysis (t/f)
|
true
|
|
|
All AA's except ___ and ____ can supply carbon for gluconeogenesis. T his is accomplished by conversion of the AA to pyruvate or oxaloacetate. The generation of ___ requires a close link b/w the urea cycle and gluconeogenesis
|
Leu, Lys
NH4+ |
|
|
conversion of AA to pyruvate or oxaloacetate is called____
|
transamination
|
|
|
Activators for glycolysis are inhibitors for _____, and vice versa
|
gluconeogenesis
|
|
|
Hormonal control for the regulation of glycolysis and gluconeogenesis refers to regulation of ____ to liver, and the activities of enzymes.
|
fatty acids
|
|
|
Pentose phosphate pathway is also called hexose monophosphate shunt and 6-phosphoglucontate pathway (t/f)
|
true
|
|
|
The pentose pathway produces the following products: ____ for reductive biosynthesis (fatty acids and steroids), ____ (nucleic acids), ____ and ____ as glycolytic intermediates
|
NADPH
ribose-5-phosphate glyceraldehyde-3-phosphate fructose-6-phosphate |
|
|
___ and ___ reciprocally regulate catabolic and anabolic pathways
|
adenine nucleotides
energy charge |
|
|
___ and ___ have (-) effects, while ___ has (+) effect in glycolysis and pyruvate dehydrogenase---but the reverse is true for TCA
|
NADH, ATP
NAD+ |
|
|
Pentose phosphate pathway
when there is a higher requirement for NADPH than ribose-5-phosphate, there is complete oxidation of G6P to ____ and resynthesis of ___ and ___ |
CO2
G6P ribulose-5-P |
|
|
Pentose phosphate pathway
when there is a higher requirement for ribose-5-phosphate than NADPH, G6P is converted to ____ and ___ by glycolysis |
fructose-6-P
glyceradehyde-3-P |
|
|
what enters the pentose phosphate pathway?
|
G6P
|
|
|
The pentose phosphate pathway works with glycolysis and TCA to produce ____ and ____
|
reducing equivalents
pentose intermediates |
|
|
Stage one of the pentose phosphate pathway has all ____ steps
|
irreversible
|
|
|
In the pentose phosphate pathway, decarboxylation of hexose to peentose yields ____ and is ____
|
NADPH
irreversible |
|
|
What are the critical products in the pentose phosphate pathway stage I?
|
NADPH, CO2, H+
|
|
|
In Stage I of the pentose phosphate pathway, cyclic glucose becomes ____ glucose and 1___ is knocked off
|
liner
carbon |
|
|
In stage II of the pentose phosphate pathway all steps are ____ and ____lead to ____
|
reversible
interconversions glycolytic intermediates |
|
|
____ catalyzes the first step in the pentose phosphate pathway, which is the ____ step, uses ___ as a cofactor, and is highly regulated by the ___/___ ratio
|
glucose-6-phosphate dehydrogenase
rate limiting NADP NADHP/NADP |
|
|
pentose phosphate pathway: high NADPH/NADP _____ G6PD, low "" ___ G6PD
|
inhibits
activates |
|
|
NADPH: primarily uses high energy electrons for ____ (__and ___)
|
biosynthesis
fatty acids steroids |
|
|
NADH: uses high energy electrons to ____ (___ via ___)
|
make energy
ATP oxidative phosphorylation |
|
|
____ is used as a cofactor by enzymes that deal with reactive oxygen species (ROS). It also provides high E electrons for reductive biosynthesis, can these functions be replaced by NADH?
|
NADPH
no |
|
|
The needs of the cell are determined by NADPH or _____, which give the direction and amount of G6P, this makes NADPH have a ___ role in biosynthesis
|
sugar intermediate
unique |
|
|
ROS can hurt ___, ___, and ___
|
DNA (genetic mutation)
lipids (membrane function) protein (enzyme inactivation) |
|
|
ROS can convert cis DB in lipid membrane to ____
|
toxic epoxide
|
|
|
____ is produced biologically by a variety of reactions most notably by "leaky" mitochondrial e- transfer. electrons can be transferred from the reduced form of coenzyme Q to oxygen, thus generating this molecule
|
superoxide anion
|
|
|
_____: produced by oxidase enzymes. Very toxic organic peroxides can be formed from 2e- reduction of O2 in compounds containing DB's (unsaturated fatty acids)
|
hydrogen peroxide
|
|
|
_____: Produced from a metal catalyzed rxn of superoxide and hydrogen peroxide. Very reactive species that can take part in free radical chain rxns.
|
hydroxyl radical
|
|
|
_____: selenium-containing enzyme that detoxifies H2O2 and other organic peroxides (lipid peroxides).
|
Glutathione peroxidate
|
|
|
____ generates reduced GSH from GSSG
|
glutathione reductase
|
|
|
Functions of glutathione: major cellualr reductant and sulfhydryl buffer, conjugated to drugs to make them more ____, ____ transport across membranes, ___ interchanges in proteins
|
soluble
AA disulfide |
|
|
____ detoxifies superoxide
|
superoxide dismutase
|
|
|
___ is a heme containing peroxidase that detoxifies H2O2
|
catalase
|
|
|
There are no known enzymatic system to deal with hydroxyl radicals (t/f)
|
true
|
|
|
liver enzymes detoxify: ___, ___, and ____, and require ___ as a cofactor
|
drugs
steroids alcohols NADPH |
|
|
You want your ROS production and antioxidant capacity to be ____
|
equil
|
|
|
G6PD mutations cause ____ decreased life span, but may confer resistance to ____
|
slightly
malaria |
|
|
drugs that exacerbate G6PD (3)
|
antibiotics (sulfamethoxazole)
antimalarials (primaquine, chloroquine) antipyretics (acetanilide) |
|
|
_____ is conjugated to endogenous and exogenous compounds producing a strongly acidic compound that is more water soluble at physiological pH, imporant in ___, ___, and ___
|
glucuronic acid
drug detoxification steroid excretion bilirubin metabolism |
|
|
glucuronic acid is synthesized in a pathway that starts with ____
|
glucose
|
