MBOD Block 4 Week 2 Flashcards
(392 cards)
<p>What are the fuels for the energy reserves of humans?</p>
<p>TAG, Protein, Glycogen, Glucose</p>
<p>What are the fuels for the energy reserves of humans?</p>
<p>TAG, Protein, Glycogen, Glucose</p>
<p>Which tissues house the energy reserves of humans?</p>
<p>Adipose, Muscle, Liver, Body fluids</p>
<p>Which tissues house the energy reserves of humans?</p>
<p>Adipose, Muscle, Liver, Body fluids</p>
<p>Which tissues has the most energy reserves?</p>
<p>Adipose</p>
<p>Which tissues has the most energy reserves?</p>
<p>Adipose</p>
<p>What are the anabolic pathways?</p>
<p>Gluconeogenesis, Glycogenesis, Protein Synthesis, Lipogenesis</p>
<p>What are the anabolic pathways?</p>
<p>Gluconeogenesis, Glycogenesis, Protein Synthesis, Lipogenesis</p>
<p>What are the substrates involved in gluconeogenesis?</p>
<p>Lactate, alanine, glycerol</p>
<p>What are the substrates involved in gluconeogenesis?</p>
<p>Lactate, alanine, glycerol</p>
<p>What is the end product of gluconeogenesis?</p>
<p>Glucose</p>
<p>What is the end product of gluconeogenesis?</p>
<p>Glucose</p>
<p>What are the substrates involved in glycogenesis?</p>
<p>Glc-1-P, Glc</p>
<p>What are the substrates involved in glycogenesis?</p>
<p>Glc-1-P, Glc</p>
<p>What is the end product of glycogenesis?</p>
<p>Glycogen</p>
<p>What is the end product of glycogenesis?</p>
<p>Glycogen</p>
<p>What are the substrates involved in protein synthesis?</p>
<p>Amino acids</p>
<p>What are the substrates involved in protein synthesis?</p>
<p>Amino acids</p>
<p>What is the end product of protein synthesis?</p>
<p>Proteins</p>
<p>What is the end product of protein synthesis?</p>
<p>Proteins</p>
<p>What are the substrates involved in lipogenesis?</p>
<p>Glc, glycerol, acetyl-CoA</p>
<p>What are the substrates involved in lipogenesis?</p>
<p>Glc, glycerol, acetyl-CoA</p>
<p>What are the end products of lipogenesis?</p>
<p>Fatty acids, TAG</p>
<p>What are the end products of lipogenesis?</p>
<p>Fatty acids, TAG</p>
What are the catabolic pathways?
Glycolysis, CAC + ETC, Glycogenolysis, Proteolysis, Lipolysis, P-gluconate pathway
What are the catabolic pathways?
Glycolysis, CAC + ETC, Glycogenolysis, Proteolysis, Lipolysis, P-gluconate pathway
What is the substrate involved in glycolysis?
Glucose
What is the substrate involved in glycolysis?
Glucose
What is the end product of glycolysis?
Pyruvate, ATP
What is the end product of glycolysis?
Pyruvate, ATP
What substrates are involved in CAC + ETC?
Acetyl CoA, OAA
What substrates are involved in CAC + ETC?
Acetyl CoA, OAA
What are the end products of CAC + ETC?
NADH, ATP, CO2
What are the end products of CAC + ETC?
NADH, ATP, CO2
What is the substrate involved in glycogenolysis?
Glycogen
What is the substrate involved in glycogenolysis?
Glycogen
What are the end products of glycogenolysis?
Glc-1-P, Glc
What are the end products of glycogenolysis?
Glc-1-P, Glc
What is the substrate involved in proteolysis?
Proteins
What is the substrate involved in proteolysis?
Proteins
What are the end products of lipolysis?
Acetyl CoA, glycerol
What are the end products of lipolysis?
Acetyl CoA, glycerol
What is the substrate involved in the P-gluconate Pathway?
Glc-6-P
What is the substrate involved in the P-gluconate Pathway?
Glc-6-P
What are the end products of the P-gluconate Pathway?
pentoses, CO2, NADPH (->FA)
What are the end products of the P-gluconate Pathway?
pentoses, CO2, NADPH (->FA)
What happens to the blood glucose in the fed state?
It increases
What happens to the blood glucose in the fed state?
It increases
What are the stages of the Feed-Fast Cycle?
Fed state; Post-prandial state; Post-absorptive state; Basal state; Fasting state; Starved state
What are the stages of the Feed-Fast Cycle?
Fed state; Post-prandial state; Post-absorptive state; Basal state; Fasting state; Starved state
After how many hours does the Post-prandial state occur?
~2hrs
After how many hours does the Post-prandial state occur?
~2hrs
After how many hours does the Post-absorptive state occur?
~6-8hrs
After how many hours does the Post-absorptive state occur?
~6-8hrs
Which state occurs after ~12 hours?
Basal state (Early fasting state)
Which state occurs after ~12 hours?
Basal state (Early fasting state)
After how many hours does the Fasting state occur?
24-72 hrs
After how many hours does the Fasting state occur?
24-72 hrs
Which state occurs after ~72 hours?
Starved state
Which state occurs after ~72 hours?
Starved state
What are the fates of fuels in the fed state?
Storage, synthesis, oxidation
What are the fates of fuels in the fed state?
Storage, synthesis, oxidation
What occurs in muscle metabolism during the resting state?
Synthesis of glycogen and protein.
What occurs in muscle metabolism during the resting state?
Synthesis of glycogen and protein.
What occurs in muscle metabolism during exerise?
Use glycogen, make lactate if O2 is limiting.
What occurs in muscle metabolism during exerise?
Use glycogen, make lactate if O2 is limiting.
What happens to the levels of Glucose, Insulin, and glucagon in the blood during the basal state?`
Glucose and insulin decreases; glucagon increases
What happens to the levels of Glucose, Insulin, and glucagon in the blood during the basal state?`
Glucose and insulin decreases; glucagon increases
What is used as an alternate fuel in the basal state?
Ketone bodies
What is used as an alternate fuel in the basal state?
Ketone bodies
Where are ketones formed?
In the liver
Where are ketones formed?
In the liver
What happens to the levels of Insulin and glucagon in the blood during the fed state?`
Insulin increases; Glucagon decreases
What happens to the levels of Insulin and glucagon in the blood during the fed state?`
Insulin increases; Glucagon decreases
What happens to the levels of Glucose, Insulin, and glucagon in the blood during the starved state?`
Glucose and insulin decreases; glucagon increases
What happens to the levels of Glucose, Insulin, and glucagon in the blood during the starved state?`
Glucose and insulin decreases; glucagon increases
What processes does insulin cause an increase in?
Glu uptake, Glc utilization, Protein syn, Lipogenesis, glycogenesis
What processes does insulin cause an increase in?
Glu uptake, Glc utilization, Protein syn, Lipogenesis, glycogenesis
What processes does insulin cause an decrease in?
Lipolysis, Glc output, gluconeogenesis, glycogenolysis, ketogenesis
What processes does insulin cause an decrease in?
Lipolysis, Glc output, gluconeogenesis, glycogenolysis, ketogenesis
What processes does glucagon cause an increase in?
Lipolysis, Glc output, gluconeogenesis, glycogenolysis, ketogenesis
What processes does glucagon cause an increase in?
Lipolysis, Glc output, gluconeogenesis, glycogenolysis, ketogenesis
What processes does glucagon cause an decrease in?
Glycogenesis
What processes does glucagon cause an decrease in?
Glycogenesis
What is the branch point for several metabolic pathways?
Glu-6-Phosphate
What is the branch point for several metabolic pathways?
Glu-6-Phosphate
Why can glucose not diffuse across the hydrophobic phospholipid bilayer of the cell membrane?
It is polar
Why can glucose not diffuse across the hydrophobic phospholipid bilayer of the cell membrane?
It is polar
How does glucose get across the membrane?
It binds to transport proteins that bind glucose on one side of the membrane and release it on the opposite side.
How does glucose get across the membrane?
It binds to transport proteins that bind glucose on one side of the membrane and release it on the opposite side.
What are the two types of transport proteins in intestinal epithelial cells?
Na+ dependent glucose transporter; Facilitative glucose transporter
What are the two types of transport proteins in intestinal epithelial cells?
Na+ dependent glucose transporter; Facilitative glucose transporter
Where do the Na+ dependent glucose transporters reside?
On the lumenal side of absorptive epithelial cells
Where do the Na+ dependent glucose transporters reside?
On the lumenal side of absorptive epithelial cells
What is the role of Na+K+ATPase?
Keeps intracellular Na+ low
What is the role of Na+K+ATPase?
Keeps intracellular Na+ low
T/F Glucose transport goes from low to high conc. in Na+ transport
TRUE
T/F Glucose transport goes from low to high conc. in Na+ transport
TRUE
T/F Na+ transport goes from high to low conc.
TRUE
T/F Na+ transport goes from high to low conc.
TRUE
T/F Facilitative Glucose Transporters move glucose from high conc to low conc w/o the expenditure of energy.
TRUE
T/F Facilitative Glucose Transporters move glucose from high conc to low conc w/o the expenditure of energy.
TRUE
Where are the amino and carboxy-terminal residues of the facilitative glucose transporters located?
In the cytoplasm.
Where are the amino and carboxy-terminal residues of the facilitative glucose transporters located?
In the cytoplasm.
How many glucose transport proteins are in the family of Facilitative glucose transporters?
Five
How many glucose transport proteins are in the family of Facilitative glucose transporters?
Five
What is the Km of GLUT 1?
1 mM
What is the Km of GLUT 1?
1 mM
What is the tissue location of GLUT2?
Liver and pancreatic B cells
What is the tissue location of GLUT2?
Liver and pancreatic B cells
What is the Km of GLUT2?
15-20mM
What is the Km of GLUT2?
15-20mM
What is the role of GLUT2?
Plays a role in the regulation of insulin in the the pancreas; Removes excess glucose from the blood in the liver.
What is the role of GLUT2?
Plays a role in the regulation of insulin in the the pancreas; Removes excess glucose from the blood in the liver.
What is the tissue location of GLUT4?
Muscle and fat cells
What is the tissue location of GLUT4?
Muscle and fat cells
What is the Km of GLUT4?
5mM
What is the Km of GLUT4?
5mM
What is the role of GLUT4?
The amount in muscle plasma membrane increases with endurance training.
What is the role of GLUT4?
The amount in muscle plasma membrane increases with endurance training.
What is the tissue location of GLUT5?
Small intestine
What is the tissue location of GLUT5?
Small intestine
What is the role of GLUT5?
Primarily a fructose transporter
What is the role of GLUT5?
Primarily a fructose transporter
How does glucose bin to the transport protein in facilitative glucose transport?
Via interactions with its hydroxyl groups
How does glucose bin to the transport protein in facilitative glucose transport?
Via interactions with its hydroxyl groups
What happens to the transport protein in facilitative Glucose transport when glucose is transported?
It undergoes a conformational change.
What happens to the transport protein in facilitative Glucose transport when glucose is transported?
It undergoes a conformational change.
What happped to the transport protein as glucose is released to the other side of the membrane?
It closes
What happped to the transport protein as glucose is released to the other side of the membrane?
It closes
What does the type of GLUT expressed by the cells reflect?
The function of glucose metabolism in that tissue.
What does the type of GLUT expressed by the cells reflect?
The function of glucose metabolism in that tissue.
Which GLUT is expressed on the surface of a red blood cell?
GLUT1
Which GLUT is expressed on the surface of a red blood cell?
GLUT1
What stimulates the recruitment of GLUT4 to the membrane to increase glucose transport?
Insulin
What stimulates the recruitment of GLUT4 to the membrane to increase glucose transport?
Insulin
What is an important function of the liver?
To maintain blood glucose levels
What is an important function of the liver?
To maintain blood glucose levels
What is the role of GLUT2 in the pancreas?
Stimulates glucose uptake in pancreatic B-cells
What is the role of GLUT2 in the pancreas?
Stimulates glucose uptake in pancreatic B-cells
What does an elevated ATP/ADP ratio result in?
An increase in cytosolic Ca++
What does an elevated ATP/ADP ratio result in?
An increase in cytosolic Ca++
What does an increase in cytosolic Ca++ cause?
It triggers the fusion of insulin-containing vesicles with the plasma membrant releasing insulin.
What does an increase in cytosolic Ca++ cause?
It triggers the fusion of insulin-containing vesicles with the plasma membrant releasing insulin.
What are some of the symptoms of decreased supply of glucose to the brain?
Lightheadedness, dizziness, coma
What are some of the symptoms of decreased supply of glucose to the brain?
Lightheadedness, dizziness, coma
What is the decreased supply of glucose to the brain due to?
A slow rate of glucose transport through the blood brain barrier.
What is the decreased supply of glucose to the brain due to?
A slow rate of glucose transport through the blood brain barrier.
What are the characteristics of the Neural Blood-Brain barrier?
1. Tight junctions between endothelial cells; 2. Narrow intercellular space; 3. Lack of pinocytosis; 4. Continuous basement membrane; 5. Glucose transporters in both membranes.
What are the characteristics of the Neural Blood-Brain barrier?
1. Tight junctions between endothelial cells; 2. Narrow intercellular space; 3. Lack of pinocytosis; 4. Continuous basement membrane; 5. Glucose transporters in both membranes.
What phosphorylates glucose once it enters a cell?
Hexokinase (HK)
What phosphorylates glucose once it enters a cell?
Hexokinase (HK)
What are the different metabolic pathways that glucose-6-phosphate can enter?
Glycolysis; Pentose Phosphate pathway; Glycogen Synthesis
What are the different metabolic pathways that glucose-6-phosphate can enter?
Glycolysis; Pentose Phosphate pathway; Glycogen Synthesis
What are the functions of glucose phosphorylation?
Controls the amount of glc taken up by cells; activates glc for further metabolism; keeps glc within cell; determines the direction of glc metabolism
What are the functions of glucose phosphorylation?
Controls the amount of glc taken up by cells; activates glc for further metabolism; keeps glc within cell; determines the direction of glc metabolism
What enzyme converts glucose-6-phosphate back to glucose?
Glucose-6-phosphatase
What enzyme converts glucose-6-phosphate back to glucose?
Glucose-6-phosphatase
What catalyzes the first step in glucose metabolism?
Hexokinase (HK)
What catalyzes the first step in glucose metabolism?
Hexokinase (HK)
What is the first step in glucose metabolism?
The transfer of phosphate from ATP to glucose resulting in glucose-6-phosphate
What is the first step in glucose metabolism?
The transfer of phosphate from ATP to glucose resulting in glucose-6-phosphate
What is HK IV also called?
Glucokinase (GK)
What is HK IV also called?
Glucokinase (GK)
What tissues are GK distributed in?
Liver, B-cells of pancreas
What tissues are GK distributed in?
Liver, B-cells of pancreas
What is the Km for HK?
~0.1mM or lower
What is the Km for HK?
~0.1mM or lower
What is the KM for GK?
10-20mM
What is the KM for GK?
10-20mM
What is HK inhibited by?
Glu-6-Phosphate
What is HK inhibited by?
Glu-6-Phosphate
What is GK induced by?
Insulin
What is GK induced by?
Insulin
Where is glucose-6-phosphatase found?
In the liver and kidney
Where is glucose-6-phosphatase found?
In the liver and kidney
What is the function of glycolysis?
Oxidation of glucose to generate ATP and lactate under anaerobic conditions via oxygen-independent substrate level phosphorylation
What is the function of glycolysis?
Oxidation of glucose to generate ATP and lactate under anaerobic conditions via oxygen-independent substrate level phosphorylation
What is pyruvate further oxidized by?
The PDH complex, the citric acid cycle and the ETC and oxidation phosphorylation
What is pyruvate further oxidized by?
The PDH complex, the citric acid cycle and the ETC and oxidation phosphorylation
Where are the glycolytic enzymes found?
In the cytosol
Where are the glycolytic enzymes found?
In the cytosol
T/F Glycolysis is oxygen independent
TRUE
T/F Glycolysis is oxygen independent
TRUE
What does the metabolism of the products depend on?
The availability of oxygen
What does the metabolism of the products depend on?
The availability of oxygen
What happens to pyruvate under aerobic conditions?
It is completely oxidized and electrons from glycolytic NADH enter the mitochondria for ATP generation.
What happens to pyruvate under aerobic conditions?
It is completely oxidized and electrons from glycolytic NADH enter the mitochondria for ATP generation.
What happens to pyruvate under anaerobic conditions?
Pyruvate and NADH are used to form lactate via the LDH reaction.
What happens to pyruvate under anaerobic conditions?
Pyruvate and NADH are used to form lactate via the LDH reaction.
What is the significance of the LDH reaction?
NAD+ is regenerated for glycolysis.
What is the significance of the LDH reaction?
NAD+ is regenerated for glycolysis.
How many ATPs are formed per glucose oxidized to pyruvate?
2
How many ATPs are formed per glucose oxidized to pyruvate?
2
What are the shuttles that transfer electrons from glycolytic formed NADH into the mitochondria?
Malate shuttle and glycerol phosphate shuttle
What are the shuttles that transfer electrons from glycolytic formed NADH into the mitochondria?
Malate shuttle and glycerol phosphate shuttle
What does the energy utilizing phase involve?
Phosphorylation of glucose by HK or GK and PFK-1 to form fru-1,6-bisphosphate
What does the energy utilizing phase involve?
Phosphorylation of glucose by HK or GK and PFK-1 to form fru-1,6-bisphosphate
How many ATPs are required for the energy-utilizing phase?
2
How many ATPs are required for the energy-utilizing phase?
2
What does the energy-generating phase involve?
Clevage by aldolase; oxidation by glyceraldehyde-3-P dehydrogenase with NADH formation; and synthesis of ATP
What does the energy-generating phase involve?
Clevage by aldolase; oxidation by glyceraldehyde-3-P dehydrogenase with NADH formation; and synthesis of ATP
How many moles of ATP are produced from the energy-generating phase?
4
How many moles of ATP are produced from the energy-generating phase?
4
how many substrate-level phosphorylation reactions occur during the energy-generating phase?
2
how many substrate-level phosphorylation reactions occur during the energy-generating phase?
2
What sugars other than glucose can feed carbons into the glycolytic pathway?
fructose, galactose, mannose, pentose sugars, glycerol
What sugars other than glucose can feed carbons into the glycolytic pathway?
fructose, galactose, mannose, pentose sugars, glycerol
T/F GK has a high specificity for glucose.
TRUE
T/F GK has a high specificity for glucose.
TRUE
What is phosphofructokinase inhibited by?
ATP and citrate
What is phosphofructokinase inhibited by?
ATP and citrate
What is phosphofructokinase activated by?
AMP and Fru-2,6-bisphosphate
What is phosphofructokinase activated by?
AMP and Fru-2,6-bisphosphate
What is an important regulator of glycolysis and gluconeogenesis?
Fru-2-6-bisphosphate
What is an important regulator of glycolysis and gluconeogenesis?
Fru-2-6-bisphosphate
What lowers the concentration of fru-2,6-bisphosphate?
Glucagon acting through cAMP
What lowers the concentration of fru-2,6-bisphosphate?
Glucagon acting through cAMP
T/F The conc of Fru-2,6-bisphosphate is high in the fed state and low in the fasting state.
TRUE
T/F The conc of Fru-2,6-bisphosphate is high in the fed state and low in the fasting state.
TRUE
What does the low conc of fru-2,6-bisphosphate cause?
It decreases glycolysis and increases gluconeogenesis
What does the low conc of fru-2,6-bisphosphate cause?
It decreases glycolysis and increases gluconeogenesis
What is pyruvate kinase inhibited by?
ATP and alanine
What is pyruvate kinase inhibited by?
ATP and alanine
What is pyruvate kinase activated by?
Fru-1,6-P2
What is pyruvate kinase activated by?
Fru-1,6-P2
What inactivates pyruvate kinase?
It being phosphorylated by glucagon via protein kinase A; promoting gluconeogenesis
What inactivates pyruvate kinase?
It being phosphorylated by glucagon via protein kinase A; promoting gluconeogenesis
What does the alanine inhibition of hepatic PK promote?
Gluconeogenesis
What does the alanine inhibition of hepatic PK promote?
Gluconeogenesis
How many moles of ATP are formed for each mole of NADH oxidized?
2.5
How many moles of ATP are formed for each mole of NADH oxidized?
2.5
How many moles of ATP are formed for each mole of FADH2 oxidized?
1.5
How many moles of ATP are formed for each mole of FADH2 oxidized?
1.5
What compound dereases the affinity of hemoglobin for oxygen?
2,3-BPG
What compound dereases the affinity of hemoglobin for oxygen?
2,3-BPG
Where in 2,3-BPG found in high concentration?
RBC
Where in 2,3-BPG found in high concentration?
RBC
What is lost when 2,3-BpG is synthesized?
An ATP
What is lost when 2,3-BpG is synthesized?
An ATP
What can 2,3-BPG be converted to that will re-enter the glycolytic pathway?
3-phosphoglycerate
What can 2,3-BPG be converted to that will re-enter the glycolytic pathway?
3-phosphoglycerate
What is substrate level phosphorylation?
The creation of a high-energy phosphate bond in a metabolite by a mechanism other than electron flow in the mitochondria membrane.
What is substrate level phosphorylation?
The creation of a high-energy phosphate bond in a metabolite by a mechanism other than electron flow in the mitochondria membrane.
What is AST?
Aspartate amino transferase; intracellular enzymes in amion acid and carbohydrate metabolism.
What is AST?
Aspartate amino transferase; intracellular enzymes in amion acid and carbohydrate metabolism.
What is an end-product of anaerobic glycolysis?
Lactate
What is an end-product of anaerobic glycolysis?
Lactate
What is lactate produced by?
Erythrocytes and by skeletal muscle after exercise.
What is lactate produced by?
Erythrocytes and by skeletal muscle after exercise.
What is lactate normally metabolized by?
Liver and cardiac muscle
What is lactate normally metabolized by?
Liver and cardiac muscle
Under what conditions will lactate increase?
If there is poor delivery of oxygen to tissues and the oxygen levels are insufficient to support normal aerobic oxidation of glucose.
Under what conditions will lactate increase?
If there is poor delivery of oxygen to tissues and the oxygen levels are insufficient to support normal aerobic oxidation of glucose.
What does lactate production form?
Hydrogen ions
What does lactate production form?
Hydrogen ions
What does excess production of lactate result in?
lactate acidosis
What does excess production of lactate result in?
lactate acidosis
What does tissue hypoxia result in?
Increased lactate production through increased NADH levels; Type A lactic acidosis
What does tissue hypoxia result in?
Increased lactate production through increased NADH levels; Type A lactic acidosis
What is Type B lactic acidosis?
Lactate accumulation in the blood in the absence of tissue hypoxia; severe hepatic failure
What is Type B lactic acidosis?
Lactate accumulation in the blood in the absence of tissue hypoxia; severe hepatic failure
What does alcohol ingestion do?
Increases NADH levels; resulting in conversion of pyruvate to lactate.
What does alcohol ingestion do?
Increases NADH levels; resulting in conversion of pyruvate to lactate.
What decreases the activity of the pyruvate dehydrogenase complex, causing pyruvate to accumulate and form lactate?
Thiamine deficiency (common in alcoholics)
What decreases the activity of the pyruvate dehydrogenase complex, causing pyruvate to accumulate and form lactate?
Thiamine deficiency (common in alcoholics)
What is the anion gap?
The difference between the commonly measured serum anions and cations; around 12-18 mEq/L
What is the anion gap?
The difference between the commonly measured serum anions and cations; around 12-18 mEq/L
What are the disorders associated with glycolysis?
Red cell glycolytic deficiencies; pyruvate dehydrogenase deficiency; PFK-1 deficiency
What are the disorders associated with glycolysis?
Red cell glycolytic deficiencies; pyruvate dehydrogenase deficiency; PFK-1 deficiency
What are hemolytic anemias caused by?
Deficiencies of RBC glycolytic enzymes such as hexokinase, gluc-6-phosphate isomerase, aldolase, triose phosphatte dehydrogenase, enolase, and pyruvate kinase; results in a deficiency of ATP
What are hemolytic anemias caused by?
Deficiencies of RBC glycolytic enzymes such as hexokinase, gluc-6-phosphate isomerase, aldolase, triose phosphatte dehydrogenase, enolase, and pyruvate kinase; results in a deficiency of ATP
What does pyruvate dehydrogenase deficiency cause?
Accumulation of pyruvate and lactate; resulting in lactic acidosis
What does pyruvate dehydrogenase deficiency cause?
Accumulation of pyruvate and lactate; resulting in lactic acidosis
What is muscle PFK-1 deficiency classified as?
A glycogen storage disease
What is muscle PFK-1 deficiency classified as?
A glycogen storage disease
Which vitamins and coenzymes are involved in glycolysis?
Thiamine (B1), Riboflavin (B2), Niacin (nicotinic acid), Pantothenic acid (B5), Pyridoxine (B6)
Which vitamins and coenzymes are involved in glycolysis?
Thiamine (B1), Riboflavin (B2), Niacin (nicotinic acid), Pantothenic acid (B5), Pyridoxine (B6)
What is the coenzyme for Thiamine?
Thiamine pyrophosphate (TPP)
What is the coenzyme for Thiamine?
Thiamine pyrophosphate (TPP)
What is the role of Thiamine?
Required for the complete oxidation of glucose via the PDH complex and the citric acid cycle.
What is the role of Thiamine?
Required for the complete oxidation of glucose via the PDH complex and the citric acid cycle.
What are the coenzymes for Riboflavin?
FAD and FADH2; FMN and FMNH2
What are the coenzymes for Riboflavin?
FAD and FADH2; FMN and FMNH2
What is the role of Riboflavin?
Required for the complete oxidation of glucose via pyruvate by the PDH complex and the citric acid cycle. Used in the glycerol-phosphate shuttle.
What is the role of Riboflavin?
Required for the complete oxidation of glucose via pyruvate by the PDH complex and the citric acid cycle. Used in the glycerol-phosphate shuttle.
What are the coenzymes for Niacin?
NAD+, NADH, NADP+, NADPH
What are the coenzymes for Niacin?
NAD+, NADH, NADP+, NADPH
What is the role of Niacin?
Required cofactor in oxidation-reduction reactions. Used in the Malate Shuttle, LDH reaction, PDH complex, and citric acid cycle.
What is the role of Niacin?
Required cofactor in oxidation-reduction reactions. Used in the Malate Shuttle, LDH reaction, PDH complex, and citric acid cycle.
What is the coenzyme for Pantothenic acid?
Coenzyme A
What is the coenzyme for Pantothenic acid?
Coenzyme A
What is the role of Pantothenic acid?
Required for the complete oxidation of glucose via pyruvate by the PDH complex and the citric acid cycle. Involved in most reactions involving acyl group transfer and metabolism
What is the role of Pantothenic acid?
Required for the complete oxidation of glucose via pyruvate by the PDH complex and the citric acid cycle. Involved in most reactions involving acyl group transfer and metabolism
What is the coenzyme for Pyridoine?
Pyridoxal phosphate (PLP)
What is the coenzyme for Pyridoine?
Pyridoxal phosphate (PLP)
What is the role of Pyridoxine?
Used in transaminations.
What is the role of Pyridoxine?
Used in transaminations.
What is the principle pathway by which every cell generates ATP from glucose?
Glycolysis
What is the principle pathway by which every cell generates ATP from glucose?
Glycolysis
T/F Glycolysis occurs under both aerobic and anaerobic conditions.
TRUE
T/F Glycolysis occurs under both aerobic and anaerobic conditions.
TRUE
What is the subcellular localization of glycolysis?
Cytosol
What is the subcellular localization of glycolysis?
Cytosol
What does glycolysis begin with?
Either glucose or glycogen
What does glycolysis begin with?
Either glucose or glycogen
What are the two phases of glycolysis?
Preparative phase; ATP-generating phase
What are the two phases of glycolysis?
Preparative phase; ATP-generating phase
How many NADHs are generated in the ATP-generating phase?
2
How many NADHs are generated in the ATP-generating phase?
2
What are the regulated steps of glycolysis?
Glucose ->G-6-P (HK); Fru-6-phos->Fru-1,6-bisphos (phosphofructokinase-1)
What are the regulated steps of glycolysis?
Glucose ->G-6-P (HK); Fru-6-phos->Fru-1,6-bisphos (phosphofructokinase-1)
How many triose phosphates are generated in the preparative phase of glycolysis?
2
How many triose phosphates are generated in the preparative phase of glycolysis?
2
What is lactate oxidized back to?
Pyruvate
What is lactate oxidized back to?
Pyruvate
What is pyruvate used to synthesize?
Glucose
What is pyruvate used to synthesize?
Glucose
Under aerobic conditions what is pyruvate completely oxidized to?
CO2 by pyruvate dehydrogenase and the TCA cycle in the mitochondria.
Under aerobic conditions what is pyruvate completely oxidized to?
CO2 by pyruvate dehydrogenase and the TCA cycle in the mitochondria.
Where does the oxidation of cytosolic NADH back to NAD+ occur?
In the mitochondria via the electron transport chain.
Where does the oxidation of cytosolic NADH back to NAD+ occur?
In the mitochondria via the electron transport chain.
T/F the mitochondrial inner membrane is impermeable to NADH
TRUE
T/F the mitochondrial inner membrane is impermeable to NADH
TRUE
What is the enzyme that works in the glycerol-3-phosphate shuttle?
glycerol 3-P dehydrogenase
What is the enzyme that works in the glycerol-3-phosphate shuttle?
glycerol 3-P dehydrogenase
What precursors for bioshythetic pathways does glycolysis provide?
Five-carbon sugars; 2,3-bis phosphoglycerate; serine; alanine; Glutamate; Fatta acids; Glycerol-P
What precursors for bioshythetic pathways does glycolysis provide?
Five-carbon sugars; 2,3-bis phosphoglycerate; serine; alanine; Glutamate; Fatta acids; Glycerol-P
What are the major requlatory enzymes of glycolysis?
Hexokinase, Phosphofructokinase; Pyruvate kinase; Pyruvate dehydrogenase
What are the major requlatory enzymes of glycolysis?
Hexokinase, Phosphofructokinase; Pyruvate kinase; Pyruvate dehydrogenase
How does ATP serve as an inhibitor of PFK-1?
ATP binds to the substrate binding site as well as the inhibitory site.
How does ATP serve as an inhibitor of PFK-1?
ATP binds to the substrate binding site as well as the inhibitory site.
How does citrate serve as an inhibitor of PFK-1?
It is a sign that the citric acid cycle is saturated and glycolysis is not needed.
How does citrate serve as an inhibitor of PFK-1?
It is a sign that the citric acid cycle is saturated and glycolysis is not needed.
How does AMP serve as an activator of PFK-1?
It binds to the activator site and increase of PFK-1 for F-6-P.
How does AMP serve as an activator of PFK-1?
It binds to the activator site and increase of PFK-1 for F-6-P.
What is the most potent activator of PFK-1?
Fructose 2,6 bis-phosphate.
What is the most potent activator of PFK-1?
Fructose 2,6 bis-phosphate.
What does F-2,6-P do?
Binds to PFK-1 and removes the inhibitory effect of ATP and turns glycolysis ON.
What does F-2,6-P do?
Binds to PFK-1 and removes the inhibitory effect of ATP and turns glycolysis ON.
What is pyruvate dehydrogenase regulated by?
The rate of ATP utilization
What is pyruvate dehydrogenase regulated by?
The rate of ATP utilization
What must all carbs be digested to in order to be metabolized?
Monosaccharides
What must all carbs be digested to in order to be metabolized?
Monosaccharides
What are the major dietary carbohydrates?
Starch, sucrose, lactose
What are the major dietary carbohydrates?
Starch, sucrose, lactose
What is starch composed of?
Amylose and amylopectin
What is starch composed of?
Amylose and amylopectin
What is amylose?
Unbranched chains composed of glucose residues linked alpha-1,4-
What is amylose?
Unbranched chains composed of glucose residues linked alpha-1,4-
What is amylopectin?
Alpha-1,4- linked chains with alpha 1-6-linked branches.
What is amylopectin?
Alpha-1,4- linked chains with alpha 1-6-linked branches.
What is sucrose made up of?
Glucose and Fructose
What is sucrose made up of?
Glucose and Fructose
What is lactose made up of?
Galactose and Glucose
What is lactose made up of?
Galactose and Glucose
What are the two types of amylase?
Salivary and pancreatic
What are the two types of amylase?
Salivary and pancreatic
Where does pancreatic amylase work?
In the lumen of the intestine
Where does pancreatic amylase work?
In the lumen of the intestine
How do salivary and pancreatic amylases begin the process of digestion of polysaccarides?
By hydrolyzing starch and glycogen.
How do salivary and pancreatic amylases begin the process of digestion of polysaccarides?
By hydrolyzing starch and glycogen.
What linkages does amylase hydrolyze?
Alpha-1,4-glycosidic linkages forming maltose, maltotriose, glucose, and limit dextrins
What linkages does amylase hydrolyze?
Alpha-1,4-glycosidic linkages forming maltose, maltotriose, glucose, and limit dextrins
Where are disaccharidases located?
In the intestinal villa
Where are disaccharidases located?
In the intestinal villa
What is the role of the glucoamylase complex?
Cleaves glucose from the nonreducing end of oligosaccharides, and cleaves maltose and isomaltase.
What is the role of the glucoamylase complex?
Cleaves glucose from the nonreducing end of oligosaccharides, and cleaves maltose and isomaltase.
How much of the total intestinal maltase activity does the glucoamylase complex have?
20%
How much of the total intestinal maltase activity does the glucoamylase complex have?
20%
How much of the total intestinal isomaltase activity does the glucoamylase complex have?
10%
How much of the total intestinal isomaltase activity does the glucoamylase complex have?
10%
What is the role of the sucrase-isomaltase complex?
Cleaves alpha-1,4-, and alpha-1,6-linkages.
What is the role of the sucrase-isomaltase complex?
Cleaves alpha-1,4-, and alpha-1,6-linkages.
How much of the total intestinal maltase activity does the Sucrase-isomaltase complex have?
80%
How much of the total intestinal maltase activity does the Sucrase-isomaltase complex have?
80%
How much of the total intestinal isomaltase activity does the sucrase-isomaltase complex have?
>90%
How much of the total intestinal isomaltase activity does the sucrase-isomaltase complex have?
>90%
Which end does glucoamylase work first?
The non-reducing end
Which end does glucoamylase work first?
The non-reducing end
What does lactase do?
Hydrolyzes the beta-1,4-linkages found in lactose, and in some complex lipids.
What does lactase do?
Hydrolyzes the beta-1,4-linkages found in lactose, and in some complex lipids.
What does trehalase do?
Hydrolyzes the alpha-1,1,-linkage found in trehalose
What does trehalase do?
Hydrolyzes the alpha-1,1,-linkage found in trehalose
What is trehalose?
A disaccharide composed of 2 glucose residues linked alpha-1,1-)
What is trehalose?
A disaccharide composed of 2 glucose residues linked alpha-1,1-)
What is the activity of maltase?
Hydrolyzes alpha-1,4,-glycosidic linkages; cleaves maltose
What is the activity of maltase?
Hydrolyzes alpha-1,4,-glycosidic linkages; cleaves maltose
What is the activity of Isomaltase?
Hydrolyzes alpha-1,6,-glycosidic linkages; cleaves isomaltose
What is the activity of Isomaltase?
Hydrolyzes alpha-1,6,-glycosidic linkages; cleaves isomaltose
What is the activty of sucrase?
Hydrolyzes B-1,4 gylcosidis linkages; hydrolyze lactose to Glc and Gal
What is the activty of sucrase?
Hydrolyzes B-1,4 gylcosidis linkages; hydrolyze lactose to Glc and Gal
