BIOCHEMISTRY-Metabolism Flashcards
These are the two sites where the metabolism takes place
Mitochondria and Cytoplasm
These three process take place in the mitochondria and the cytoplasm
Heme synthesis, Urea cycle, Gluconeogenesis
Name the processes that take place in the mitochondria
Fatty acid oxidation (β oxidation)
Acetyl CoA production, TCA cycle
Oxidative phosphorylation
Which processes take place in the cytoplasm?
Glycilysis Fatty acid synthesis HMP shunt Protein synthesis Steroid synthesis Cholesterol synthesis
What does Glucokinase catalyzes?
Catalyzes the phosphorylation of glucose using a molecule of ATP
What is the function of Kinase?
Uses ATP to add high energy phosphate group onto substrate
This enzyme adds inorganic phosphate onto substrate without using ATP
Phosphorylase
What does the Phosphatase does to the substrate?
removes phosphate group
This enzyme catalyzes oxidation reduction reactions
Dehydrogenase
What does Hydroxylase does to the substrate?
Adds hydroxyl group (-OH)
Which is the effect of Carboxylase?
Transfers CO2 groups with help of biotin
This enzyme relocates a functional group within a molecule
Mutase
This enzyme manages the glycolysis
Phosphofructokinase-1 (PFK-1)
Who are the positive regulators of PFK-1
AMP +
Fructose- 2, 6- biphosphate +
These are the negative regulators of PFK-1
ATP -
citrate -
Which process is fructose-1,6 biphosphatase related?
Gluconeogenesis
ATP and acetyl-CoA which kind of regulators are for fructose-1,6 biphosphatase?
positive regulators
These are the negative regulators for fructose-1,6 biphosphatase
AMP -
Fructose- 2, 6- biphosphate -
Which are the alternative names for Citric acid cycle?
Tricarboxylic acid cycle (TCA) or Krebs cycle
This enzyme has a great importance on TCA cycle
Isocitrate dehydrogenase
This is the positive regulator in Citric acid cycle
APD+
Who are the negative regulators in Krebs cycle?
ATP- and NADH
This enzyme manages the glycogenesis
Glycogen synthase
These are positive regulators in glycogenesis
Glucose-6-phosphate
Insulin
Cortisol
Epinephrine and glucagon are negative regulators in this process
Glycogenesis
Which process is managed by glycogen phosphorylase?
Glycogenolysis
Glucose-6-phosphate, Insulin and ATP are negative regulators for this process
Glycogenolysis
Who are positive regulators in Glycogenolysis?
AMP, Epinephrine and glucagon
This enzyme is related to hexose monophosphate shunt…
Glucose-6-phosphate dehydrogenase (G6PD)
Is NADP a positive or negative regulator in pentose phosphate pathway?
Positive
It´s an alternative name for hexose monophosphate shunt…
Pentose phosphate pathway
Is NADPH a positive or negative regulator in hexose monophosphate shunt?
Negative
Which process is Carbamoyl phosphate synthetase II related to?
De novo pyrimidine synthesis
This enzyme is related to De novo purine synthesis
Glutamine-phosphoribosylpyrophosphate (PRPP) amidotransferase
These are negative regalutors in De Novo purine synthesis
AMP, IMP, GMP
The carbamoyl phosphate synthetase I is related to this process
Urea Cycle
The N-acetylglutamate is a positive regulator in this process
Urea cycle
Which enzyme is related to fatty acid oxidation?
Carnitine acyltransferase I
Who is a negative regulator in Fatty acid synthesis?
Glucagon and palmitoyl-CoA
Act as an enzyme in the Fatty acid synthesis
Acetyl CoA carboxylase (ACC)
Insulin and citrate are postive regulators in fatty acid oxidation or fatty acid synthesis
In the fatty acid synthesis
Which process has HMG- CoA synthase as an enzyme?
Ketogenesis
Which enzyme acts in Cholesterol synthesis?
HMG- CoA reductase
Insulin and Thyroxine are positive regulators in this process
Cholestherol synthesis
Which are the negative regulators in Cholestherol synthesis?
Glucagon, cholesterol
How many ATP are produced in the aerobic metabolism via malate aspartate shuttle?
32 net ATP
Which organs are related to aerobic metabolism via malate aspartate shuttle?
Heart and liver
How many ATP are produced in the aerobic metabolism via glycerol 3 phosphate?
30 net ATP
Which tissue is related to aerobic metabolism via glycerol 3 phosphate?
Muscle
How many ATP are produced in the anaerobic glycolysis?
2 net ATP per glucose molecule
Can ATP hydrolysis be coupled to energetically favorable reactions?
False, ATP hydrolysis can be coupled to energetically unfavorable reactions
Which element causes glycolysis to produce zero net ATP?
Arsenic
From which pathway is NADPH produce?
HMP shunt
Where is used NADPH?
Anabolic processes
Respiratory burst
Cytochrome P450 system
Glutathione reductase
In which processes is NAD+ generally used?
Catabolic processes
During the catabolic processes which is the function for NAD+ ?
To carry reducing equivalents away as NADH
In which processes is NADPH generally used?
Anabolic processes
These are examples of anabolic processes
Steroid and fatty acid synthesis
During the anabolic processes which is the function for NADPH?
As a supply of reducing equivalents
Which is the first step of glycolysis?
Phophorylation of glucose to yield glucose 6-P
In which other process Phophorylation of glucose to yield glucose 6-P is the first step?
Glycogen synthesis in the liver
Which enzyme catalyses Phophorylation of glucose to yield glucose 6-P?
Hexokinase or glucokinase depending in the tissue
At low glucose concetrations who sequesters glucose in the tissue?
Hexokinase
When there is high glucose concentration, who stores glucose excess?
The liver
These are the location of action of the Glucokinase
Liver, β cells of pancreas
Which are the location of action of the Hexokinase?
Most tissues, but not Liver nor β cells of pancreas
What is the difference in Km between Hexokinase and Glucokinase
Hexokinase has lower Km but ↑ affinity
and Glucokinase has Higher Km but ↓ affinity
For the Glucokinase what does it meas that has Higher Km but ↓ affinity?
This means that it operates only when serum glucose levels are high.
If tissues need to use glucose at lower serum levels which enzyme is used?
Use the higher affinity (lower Km) hexokinase
How is the Vmax in the Hexokinase
Lower and decrease Capacity
Higher V max with increase capacity…. Glucokinase or Hexokinase?
Glucokinase
Feedback inhibited by glucose 6 P….Glucokinase or Hexokinase?
Hexokinase
Gene mutation associated with maturity onset diabetes of the young… Glucokinase or Hexokinase?
Glucokinase
Which is the equation in the net glycolysis?
Glucose+ 2Pi+ 2ATP+ 2 NAD→ 2 pyruvate+ 2 ATP+ 2 NADH+ 2 H+ 2 H2O
Is the equation in the net glycolysis balanced?
Not balanced chemically
On what depends the exact balance equation in the net glycolysis?
Ionization state of reactants and products
For the glucose conversion to glucose 6 phosphate is needed the hexokinase/glucokinase, what else is required?
ATP
For the fructose 6 P conversion to fructose 1,6 BP is required ATP, wich enzyme catalyzes this reaction?
Phosphofructokinase
Which processes produces ATP during the glycolysis?
1,3 BPG→ 3PG
Phosphoenolpyruvate → Pyruvate
Which enzyme catalyzes the conversion from Phosphoenolpyruvate → Pyruvate?
Pyruvate kinase
Which enzymes manages the conversion from fructose 2, 6 biphosphate to Fructose 6 phosphate?
Fructose biphosphatase 2 (FBPase2)
When does Fructose biphosphatase 2 (FBPase2) is activated?
Activated in fasting state
Which enzymes manages the conversion from Fructose 6 phosphate to fructose 2, 6 biphosphate?
Phosphofructokinase-2 (PFK 2)
When does Phosphofructokinase-2 is activated?
Activated during fed state
This enzymes are the same bifunctional enzyme whose function is reversed by phosphorylation by protein kinase A
Phosphofructokinase-2 (PFK 2) and Fructose biphosphatase 2 (FBPase2)
During the Fasting state which process is increase, Glycolysis or Gluconeogenesis
Gluconeogenesis
Who is primary increase during the fasting state?
Increase Glucagon
The increase of Glucagon during fasting state increases cAMP, after this… who is increased?
↑ protein kinase A
If the protein Kinase A is increased during fasting, which enzyme is increased and which one decreased?
Fructose biphosphatase 2 (FBPase2) is increased
Phosphofructokinase-2 (PFK 2) is decreased
Who is primary increase during the fed state?
Increase Insulin
The increase of insulin during fed state decreases cAMP, after this… who is decreased?
↓ protein kinase A
If the protein Kinase A is decreased during feeding, which enzyme is increased and which one decreased?
Fructose biphosphatase 2 (FBPase2) is decreased
Phosphofructokinase-2 (PFK 2) is increased
This mitochondrial enzyme complex links the glycolysis and TCA cycle?
Pyruvate dehydrogenase complex
When does the Pyruvate dehydrogenase complex is activated?
Active in fed state
Which is the reaction catalyzed by Pyruvate dehydrogenase complex?
pyruvate+ NAD+ CoA→ acetyl-CoA+CO2 + NADH
In the mitochondrial enzyme complex which links the glycolysis and TCA cycle, how many enzymes and cofactors it contains?
Contains 3 enzymes that require 5 cofactors
Which are the 5 cofactors in the Pyruvate dehydrogenase complex?
Pyrophosphate (B1 thiamine; TPP) FAD (B2 riboflavin) NAD (B3 NIacin) CoA (B5 pantothenate) Lipoic Acid
What happens to NAD/ NADH ratio, ADP and Ca2+ during exercise in the Pyruvate dehydrogenase complex?
They´re increased
The Pyruvate dehydrogenase complex to which complex is it similar?
α ketoglutarate dehydrogenase complex
In the TCA cycle what is the final product of α ketoglutarate
Succinyl CoA
Which elemet inhibits lipoic acid?
Arsenic
During the inhibition caused by Arsenic to lipoic acid which symptoms are common?
Vomiting, rice watter stools, garlic breath
If there is a Pyruvate dehydrogenase complex deficiency, which would be the consequences?
Causes a buildup of pyruvate that gets shunted to lactate (via LDH) and alanine (via ALT)
Which are the only purely ketogenic aminoacids?
Lysine and Leucine
Which findings are common during the Pyruvate dehydrogenase complex deficiency?
Neurologic defects, lactic acidosis, increase alanine starting in infancy
This is the treatment for Pyruvate dehydrogenase complex deficiency
Increase intake of ketogenic nutrients (high content or increase lycine and leucine)
From Glucose we can get pyruvate, but from pyruvate what do we get?
Alanine
Oxaloacetate
Acetyl CoA
Lactate
Which pyruvate product is related to Cahill cycle?
Alanine
This pyruvate product is the result of Cori cycle
Lactate
Which enzyme and cofactor helps during the pyruvate metabolic pathway in order to get Alanine?
Alanine aminotransferase (B6 as a cofactor)
What is the importance of alanine?
It carries amino groups to the liver from muscle
Which enzyme and cofactor helps during the pyruvate metabolic pathway in order to get Oxaloacetate?
Pyruvate carboxylase (biotin as cofactor)
What is the importance of Oxaloacetate?
Can replenish TCA cycle or be used in gluconeogenesis
Which enzyme and cofactor helps during the pyruvate metabolic pathway in order to get Acetyl CoA?
Pyruvate dehydrogenase (B1, B1, B3, B5, lipioc acid)
What is the importance of Pyruvate dehydrogenase?
Transition from glycolysis to the TCA cycle
Which enzyme and cofactor helps during the pyruvate metabolic pathway in order to get Lactate?
Lactic acid dehydrogenase (B3)
End of anaerobic glycolysis
Lactate
This is the step preview to entering the Kreb cycle
Pyruvate→ Acetyl Co’A
During the transition from pyruvate → Acetyl CoA in the TCA cycle, what is produce?
1 NADH and 1 CO2
Where does the Krebs cycle takes place?
Mitochondria
Which are the results from the TCA cycle?
3 NADH, 1 FADH2, 2 CO2, 1 GTP per acetyl CoA
How much ATP is needed for each acetyl CoA?
10
Who requires the same cofactors as the pyruvate dehydrogenase complex?
α ketoglutarate
Which cofactors does α ketoglutarate needs?
B1, B2, B3, B5, lipoic acid
Which is the mnemonic for the Krebs cycle?
Citrate Is Krebs Starting Substrate For Making Oxaloacetate
Which enzyme is required for Acetyl CoA to get to Citrate?
Citrate synthase
Which enzyme is required for Oxalatoacetate to get to Citrate?
Citrate synthase
Which enzymes are irreversible during Krebs cycle?
Citrate synthase
Isocitrate dehydrogenase
α KG dehydrogenase
Which are the substrates from TCA cycle?
Citrate Isocitrate α Ketoglutarate Succinyl CoA Succinate Fumarate Malate Oxaloacetate
The NADH electrons produce from glycolysis, where do they go?
Thet enter the mitochondria
How does the NADH electrons produce from glycolysis enter the mitochondria?
Via the malate aspartate or glycerol 3 phosphate shuttle
Where are transfered the FADH2 electrons in the mitochondria?
To complex II
In the mitochondria, who is transfered at lower energy the FADH2 or NADH electrons?
FADH2
What is the result of the passage of electrons in the mitochondria?
Results in the formation of proton gradient
What is the result of proton gradient coupled to oxidative phosphorylation?
Production of ATP
On what consists the complex II?
Succinate dehydrogenase
Who inhibits the complex IV in the mitochondria?
Cyanide
CO
Antimycin A inhibits this complex in the mitochondria
Complex III
Rotenone inhibits Mitochondria complex V
False Rotenone inhibits Compex I
Who inhibits Mitochondria Complex V?
Oligomycin
What is produce by Mitochondria complex I, III, IV and V?
H+
Acts as a proton ionophore, an agent that can shuttle protons (hydrogen cations) across biological membranes. It defeats the proton gradient across mitochondria and chloroplast membranes.
2,4 Dinitrophenol
By which enzyme is ATP produce?
ATP synthase
How many ATP are produce for each NADH?
2.5 ATP
By each FADH2 how many ATPs are produce?
1.5 ATP
This poisoning directly inhibit electron transport, causing a ↓ proton gradient and block of ATP synthesis
Rotenone
Cyanide
Antymicin A
CO
Directly inhibit mitochondrial ATP synthase, causing an ↑ proton gradient
Oligomycin
Why it isn´t produce any ATP by Olygomycin?
Electron transport stops
Produces heat. Increase permeability of memebrane, causing a decrease proton gradient and increase O2 consumption
2, 4 Dinitriphenol
Aspirin
Thermogenin
With the 2, 4 Dinitriphenol how is the ATP synthesis and the electron transport?
ATP synthesis stops
Electron transport continues
Which is the illicitly use for 2, 4 Dinitriphenol?
For weight loss
Which is a common secondary effect of aspirin after an overdose?
Fever
Where do we find thermogenin?
In brown fat
Which are the irrevesible enzymes during the gluconeogenesis?
Pyruvate Carboxylase
Phosphoenolpyruvate carboxykinase
Fructose 1,6 bisphosphatase
Glucose 6 phosphate
In the gluconeogenesis, where does the pyruvate→ oxaloacetate is performed?
In mitochondria
In the gluconeogenesis, which enzymes catalyzes pyruvate→ oxaloacetate?
Pyruvate carboxylase
In the gluconeogenesis, which cofactors does pyruvate carboxylase needs to catalyze pyruvate→ oxaloacetate?
Biotin
ATP
Who activates Pyruvate carboxylase?
Acetyl CoA
In the gluconeogenesis, where does the oxaloacetate → Phosphoenolpyruvate is performed?
In Cytosol
In the gluconeogenesis, which enzymes catalyzes oxaloacetate → Phosphoenolpyruvate?
Phosphoenolpyruvate carboxykinase
In the gluconeogenesis, what does Phosphoenolpyruvate carboxykinase needs to catalyze oxaloacetate → Phosphoenolpyruvate
Requires GTP
In the gluconeogenesis, where does the Fructose 1,6 BP→ Fructose 6 phosphate is performed?
In cytosol
In the gluconeogenesis, which enzymes catalyzes Fructose 1,6 BP→ Fructose 6 phosphate?
Fructose 1-6 biphosphatase
In the gluconeogenesis, which cofactors positively stimulates Fructose 1-6 biphosphatase to catalyze Fructose 1,6 BP→ Fructose 6 phosphate
Citrate
In the gluconeogenesis, which cofactors inhibits Fructose 1-6 biphosphatase to catalyze Fructose 1,6 BP→ Fructose 6 phosphate
Fructose 2,6 biphosphate
In the gluconeogenesis, where does the Glucose 6 P→ Glucose?
In Endoplasmic Reticulum
In the gluconeogenesis, which enzymes catalyzes Glucose 6 P→ Glucose?
Glucose 6 phosphatase
Primarily where does the gluconeogenesis happens? What is it purpose?
Occurs primarily in the liver, serves to mantain euglycemia during fasting.
Which other organs can we find the irrevesible enzymes of the Gluconeogenesis?
Kidney, intestinal ephithelium.
What happens if there is a deficiency of the key glucogenic enzymes?
Hypoglicemia
Why can´t the muscle participate in gluconeogenesis?
Because it lacks glucose 6 phosphatase
Which other route serves as glucose source?
Odd chain fatty acids yield 1 propionyl CoA during metabolism, which can enter the TCA cycle (as succinyl CoA) undergo gluconeogenesis
Why can´t the Even chain fatty acids produce new glucose?
Since they yield only acetyl CoA equivalents
Provides a source if NADPH from abundantly avaible glucose 6-P
HMP shunt (pentose phosphate pathway)
What is required for the reductive reactions?
NADPH
This are examples of reductive reactions that need NADH
Glutathione reduction inside RBCs, fatty acid and cholesterol biosynthesis
What else does the HMP shunt yields?
Yields ribose for nucleotide synthesis and glycolytic intermediates
Which are the distinctic phases in the pentose phosphate pathway
Oxidative and nonoxidative
Where do the oxidative and nonoxidative phases of the HMP shunt occurs?
cytoplasm
How many ATPs are produced and used during the HMP shunt?
No ATP is used or produced
These are the sites where the pentose phosphate pathway take place
Lacting mamary glands, liver, adrenal cortex (sites of fatty acid or steroid synthesis) RBCs
In the oxidative and nonoxidative reactions in the HMP shunt, Which one is irreversible?
Oxidative
In the oxidative reaction in the pentose phosphate pathway, this is the start point
Glucose 6 Phosphate
These two metabolic pathways have Glucose 6 phosphate as the start point
Glycolysis and pentose phosphate pathway
Which are the products from the oxidative phase in the HMG shunt?
CO2
2 NADPH
Ribulose 5 P
Glucose 6 P dehydrogenase is one of the main enzymes in which metabolic process?
pentose phosphate pathway
Who stimulates and who inhibits the oxidative phase in the HMG shunt?
NAPD stimulates
NADPH exces inhibits
This is the end point of the oxidative reaction, but also the start point in the nonoxidative reaction in the pentose phosphate pathway
Ribulose 5 P
Which are the final products of the nonoxidative phase with the Ribulose 5 P?
Ribose 5 P
G3P
F6P
Which enzyme is needed for Ribulose 5 P to get to the final products?
Phosphopentose isomerase transketolases
Which cofactor is required for Ribulose 5 P to get to the final products?
Requires B1
In the Respiratory burst what does it involves?
Involves the activation of the phagocyte NADPH oxidase complex
What other name does the respiratory burst receives?
Oxidative burst
During the Respiratory burst, which is the substrate for the phagocyte NADPH oxidase complex?
O2
These cells are example of phagocyte NADPH oxidase complex
Neutrophils, monocytes
What is the importance of the respiratory burst?
Plays an important role in the immune response→ rapid release of reactive oxygen species
Who plays an important role in the creation and neutralization of Reactive Oxigen Species (ROS)?
NADPH
Who gives the blue green heme containing pigment to the sputum?
Myeloperoxidase
Which disease has NADPH oxidase deficiency?
Chronic granulomatous disease (CGD)
What happens to the phagocytes of patients with Chronic Granulomatous disease (CGD)?
Phagocytes can utilizr H2O2generated by invading organism and convert it to ROS
The CGD patients are at higher risk for infection, from whom ?
Catalase + species
Which benefit Catalase + species have against phagocytes?
Catalase + species are capable of neutralizing their own H2O2, leaving phagocytes without ROS for fighting infections
Which bacterias are examples of catalase + species?
S. Aureus
Aspergillus
Can P. aeruginosa kill competing microbes? How?
Pyocyanine of P. aeruginosa functions to generate ROS to kill competing microbes
This protein inhibits microbial growth via iron chelation
Lactoferrin
Where do we find Lactoferrin?
In secretory fluids and neutrophils
What is the relationship between NADPH and glutathione?
NADPH is necessary to keep glutathione reduced
What repercussion has that NADPH reduces glutathione?
Detoxifies free radicals and peroxides
What happens to the RBC if there is a decrease in NADPH?
Leads to an hemolytic anemia due to poor RBC defence agianst oxidizing agents
Give examples of oxidizing agents that can lead to hemolytic anemia?
Fava beans, sulfonamides, primaquine, antituberculosis drugs
What else can precipitate hemolysis and it´s worst if there is a decrease of NADPH?
Infection
How does infection can lead to hemolysis?
Free radicals generated via inflamatory response can diffuse into RBCs and cause oxidative damage
If there is a Glucose 6 phosphate dehydrogenase deficiency, which would be the results?
A lack of NADPH, and with that a glutathione increased resulting in increased radicals and peroxides
Which kind of genetic disorder is Glucose 6 phosphate dehydrogenase deficiency?
X linked recessive disorder
Which is the most common human enzyme deficiency?
Glucose 6 phosphate dehydrogenase deficiency
In whom is the glucose 6 phosphate dehydrogenase deficiency more prevalent?
Among blacks
How is related the glucose 6 phosphate dehydrogenase deficiency to the malaria?
Increases malarial resistance
What is the product of the Glucose 6 phosphate after 6 phosphate dehydrogenase catalazes it?
6 phosphogluconate and NADH
Oxidized Hemoglobin precipitaed within RBCs
Heinz bodies
Result from the phagocytic removal of Heinz bodies by splenic macrophages
Bite cells
Are consider Disorders of fructose metabolism
Essential fructosuria
Fructose intolerance
Involves a defect in fructokinase
Essential fructosuria
The essential fructosuria, which kind of mode of inheritance does it follows?
Autosomal recessive
Clinically, how is consider the Essential fructosuria?
A benign, asymptomatic condition
