wk 2 - Gluconeogenesis & General Regulatory Mechanisms COPY Flashcards
In Cori Cycle, lactate is produced in the ———– (organ) and it is converted to ———- (carbohydrate).
In Cori Cycle, lactate is produced in the liver and it is converted to glucose.
10?
(pathway)
lipolysis
(triacylglycerols/fatty acids are broken down via beta oxidation to produce acetyl coa molecules & glycerol)
Glycerol is mostly found in the adipose tissue (subcutaneous), it goes to the —-where it gets converted to —-, which can be used as a fuel in other tissues.
a) Adipose tissue
b) Muscle
c) Liver
d) Glucose
e) Glycogen
Glycerol is mostly found in the adipose tissue (subcutaneous), it goes to the liver where it gets converted to glucose, which can be used as a fuel in other tissues.
Which 3 reactions during glycolysis are irreversible during gluconeogenesis?
a) Step 1, 8 & 10
b) Step 1, 3 & 10
c) Step 1-3
d) Step 8-10
b) Steps 1, 3 & 10
(3 kinases)
S1 - hexokinase requires 2 ATP
S3 - PFK-1 requires 2 ATP
S10 - pyruvate kinase requires 4 ATP
The liver itself can’t use the ketone bodies as a source of energy as it lacks the enzyme ____ ________ ___ ________, also called _________, that is responsible for producing acetyl CoA from the ketone bodies.
The liver itself can’t use the ketone bodies as a source of energy as it lacks the enzyme β-ketoacyl-CoA transferase, also called thiophorase, that is responsible for producing acetyl CoA from the ketone bodies.
during starvation, in what order are the following molecules utilised as fuel?
- proteins (muscle)
- ketones
- glucose
- fatty acids + minimal proteins
- glycogen
- Glucose
- Glycogen
- Fatty acids + minimal protein
- Ketones
- Proteins (muscle)
…then death
during starvation, the human body’s first priority is to:
provide sufficient glucose to brain and other tissues that are dependent on it (Figure A)
8?
(pathway)
glycolysis - TCA cycle
pyruvate is sent from the cytoplasm into the mitochondria via pyruvate translocase, and is then converted to acetyl CoA via pyruvate deydrogenase complex (PDH) to enter the TCA cycle
________ is an important product for the synthesis of ATP and citrate via the Krebs Cycle. It is produced from:
- fatty acids (during beta oxidation - lipolysis)
- glucose (end product of glycolysis)
- amino acids (during Cahill cycle)
- ketone bodies (precursor for ketogenesis)
- oxaloacetate (during Gluconeogenesis)
- and ethanol (via ADH)
Acetyl CoA
If acetyl CoA is the precursor for production of energy via TCA cycle, what is the purpose of converting acetyl CoA by the liver mitochondria to ketone bodies, then re-converting ketone bodies to acetyl CoA in the tissues?
ketone bodies are water soluble and can be transported from the liver to other tissues easily without the need of albumin or lipoproteins as carriers.
In the human body, which fuel store can last for the longest time?
adipose fat
Lymphatic cells absorb and transport fatty acids and lipids as _____ from the digestive system
Lymphatic cells absorb and transport fatty acids and lipids as lymph from the digestive system
When _________ stores are depleted, the liver is able to synthesize glucose from lactate, via ___________
When Glycogen stores are depleted, the liver is able to synthesize glucose from lactate, via gluconeogenesis
13?
(pathway)
ketogenesis
acetyl CoA is used to make ketone bodies - betahydroxybutyrate & acetoacetate
A ketogenic amino acid can be degraded directly into ________, which is the precursor of ketone bodies
A ketogenic amino acid can be degraded directly into acetyl-CoA, which is the precursor of ketone bodies
When do muscle cells use the Cahill cycle and not the Cori-cycle?
When the muscles need to get rid of ——-
a) Ammonia
b) Oxaloacetate
c) Water
d) Lactic acid
a) Ammonia
In the Cahill cycle, pyruvate is converted to alanine in muscle cells, then to glucose in the liver when there is a need to transfer ammonia to the liver.
Compartmentation is the seperation of ________ and _________ pathways
Compartmentation is the seperation of synthesis and degradation pathways
What is the main hormone secreted to reduce the blood glucose level?
a) Glucagon
b) Growth hormone
c) Insulin
d) Oestrogen
c) Insulin
Glycolysis produces —– ATP, whereas, gluconeogenesis consumes —- ATP.
Glycolysis produces 2 ATP, whereas, gluconeogenesis consumes 6 ATP.
Glycogen is formed from ——, which is glycolysed to —-, then to —–, then getting stored in ——— as glycogen.
a) Adipose tissues and liver
b) Glucose
c) Glucose-1-phosphate
d) Glucose-6-phosphate
e) Muscle and liver
Glycogen is formed from Glucose, which is glycolysed to Glucose-6-phosphate then to Glucose-1-phosphate, then getting stored in Muscle and liver as glycogen.
The glycogen stored in muscle is made accessible to be used by other organs.
a) True
b) False
b) False
- Only the glycogen stored in the liver can be made accessible
to other organs.
The Cori cycle (lactate to glucose) normally accounts for 20% of glucose turnover, but it was shown to be increased to 50% in ————— patients.
a) Arthritis
b) Cachectic cancer
c) Cirrhosis
d) Diabetic
e) Glucoma
The Cori cycle (lactate to glucose) normally accounts for 20% of glucose turnover, but it was shown to be increased to 50% in Cachectic cancer patients.
(Cachexia is characterized by loss of adipose tissue and skeletal muscle mass - wasting syndrome)
ethanol is primarily metabolised by the liver, converted to ___________ by alcohol dehydrogenase (ADH) which takes place in the cytoplasm. This toxic product is then converted to ______ by aldehyde dehydrogenase
(some is metabolised in the stomach - the stomach lining contains ADH)
ethanol is primarily metabolised by the liver, converted to acetaldehyde by alcohol dehydrogenase (ADH) which takes place in the cytoplasm. This toxic product is then converted to the relatively inert acetate by aldehyde dehydrogenase
(some is metabolised in the stomach - the stomach lining contains ADH)
GLUT2 is a facilitated glucose transporter (glucose carrier). When the glucose concentration goes above 30mM, GLUT2 is up-regulated at the _____ _______ ________, enhancing the capacity of glucose transport
GLUT2 is a facilitated glucose transporter (glucose carrier). When the glucose concentration goes above 30mM, GLUT2 is up-regulated at the brush border membrane, enhancing the capacity of glucose transport.
——— is characterized by loss of adipose tissue and skeletal muscle mass.
Cachexia is characterized by loss of adipose tissue and skeletal muscle mass.
19?
(pathway)
glycolysis
the _____ _____ ____ carries nutrients from the intestine to the liver
the hepatic portal vein carries nutrients from the intestine to the liver
name the 5 amino acids that are exclusively glucogenic:
- Threonine
- Tyrosine
- Isoleucine
- Phenylalanine
- Tryptophan
(T, Y, I, F, W)
Alanine, glycerol and lactate are precursors of gluconeogenesis. Where can you find them in the body?
- alanine - from muscle
- glycerol - from adipose tissue
- lactate - from muscle, RBC’s, via the cori cycle
12?
(pathway)
HMG CoA reductase, can be either:
- melvanoate pathway (for cholesterol synthesis)
- or ketogenesis
Oxaloacetate has the choice to be converted to —- (gluconeogenesis) if the human body ——- to use energy (ATP) or to —– (glycolysis) if the human body —— energy (ATP)
a) Acetyl CoA & citric acid
b) Lactate or ethanol
c) Needs
d) Doesn’t need
Oxaloacetate has the choice to be converted to lactate or ethanol (gluconeogenesis) if the human body doesnt need to use energy (ATP) or to Acetyl CoA & citric acid (glycolysis) if the human body needs energy (ATP)
What will happen to your body’s glycogen stores during fasting? Why?
glycogenolysis, conversion of glycogen to glucose for energy to supply plasma glucose to tissues (brain, RBC, testes, renal mediulla & embryonic tissues)
Fasting requires all the glucose to be synthesized from ———— precursors
Fasting requires all the glucose to be synthesized from gluconeogenesis precursors
What is the starting material for gluconeogenesis?
a) Amino acids
b) Fats
c) Lipids
d) Oxaloacetate
d) Oxaloacetate
Why it is recommended to eat while you drink alcohol?
a) Because ethanol makes you feel hungry
b) Because ethanol produces low concentration of NADH, which inhibits glycogenesis (supress glycogen production and cause hypoglycaemia)
c) Because ethanol produces high concentration of NADH, which inhibits gluconeogenesis (supress glucose production and cause hypoglycaemia)
d) Because ethanol produces high concentration of NADH, which inhibits glycogenesis (supress glycogen production)
c) Because ethanol produces high concentration of NADH, which inhibits gluconeogenesis (supress glucose production and cause hypoglycaemia)
which fuel is preferred by skeletal and heart muscle at times of rest:
Fatty acids
(aerobic environment)
ATP is released in —— and it is consumed in ——.
a) Glycolysis
b) Gluconeogenesis
ATP is released in Glycolysis and it is consumed in Gluconeogenesis.
What is the end product of glycogen in muscles during exercise?
a) Acetate
b) Amino acids
c) Glucose
d) Lactate
e) Ketonic bodies
d) Lactate
- exercise changes the cell to an anaerobic environment (from depleted O2 due to an increased cellular respiration rate) = fermentation of pyruvate to produce lactate
In the human body, which fuel store is the largest?
a) Adipose fat
b) Liver glycogen
c) Muscle glycogen
d) Muscle protein
d) Muscle protein
Although costly in Phosphate bonds (net 4), the ____ ____ allows the organism to accommodate to large fluctuations in energy needs of skeletal muscle between rest and exercise
Although costly in Phosphate bonds (net 4), the cori cycle allows the organism to accommodate to large fluctuations in energy needs of skeletal muscle between rest and exercise
What is the fuel of the brain in case of starvation?
a) Glucose
b) Glycogen
c) Glucose 6-phosphate
d) Ketone bodies
e) Starch
d) Ketone bodies
Which organ does all the following?
- Synthesises glucose
- Stores glycogen
- Produces ATP
- Secrets wastes
- Provides fuel to brain, muscle and other organs
liver
In a starvation state, once TAG stores are depleted, ______ degradation accelerates which will eventually lead to death due to loss of heart, liver, and kidney function
In a starvation state, once TAG stores are depleted, protein degradation accelerates which will eventually lead to death due to loss of heart, liver, and kidney function
After 40 days of starvation, the brain gets ___% of its energy from ketone bodies
After 40 days of starvation, the brain gets 70% of its energy from ketone bodies
_________ _______ uses ATP to do mechanical work
skeletal muscle uses ATP to do mechanical work
In glucose synthesis from glucose-6-phosphate, glucose 6-phosphatase is activated by ———– (metal cation)
Mg2+
The process whereby precursors such as lactate, pyruvate, glycerol, and amino acids are converted to glucose is termed ___________
Gluconeogenesis
What is the main hormone secreted to increase the blood glucose level?
a) Glucagon
b) Growth hormone
c) Insulin
d) Oestrogen
a) Glucagon
Where in body you can find mostly triacylglycerol?
adipose tissues
the _____ processes fats, CHO’s and proteins from the diet, synthesises ans distributes lipids, ketone bodies and glucose for other tissues & converts excess nitrogen (ammonia) to urea.
the liver processes fats, CHO’s and proteins from the diet, synthesises ans distributes lipids, ketone bodies and glucose for other tissues & converts excess nitrogen (ammonia) to urea.
Acetone, acetoacetate and β-hydroxybutyrate are classified as ——-
ketone bodies
In the Cahill Cycle, blood transfers glucose from —–
a) Liver to muscle
b) Muscle to liver
c) Muscle to pancreas
d) Pancreas to liver
a) Liver to muscle
21?
(pathway)
Pentose phosphate pathway
Gluconeogenesis costs __ ATP to produce one glucose molecule
Gluconeogenesis costs 6 ATP to produce one glucose molecule
In humans, two amino acids are exclusively ketogenic:
Lysine & Isoleucine
the human body has ‘reserves’ for starvation for ___-___ months, however our glucose reserves are exhausted after ___ day/s
the human body has ‘reserves’ for starvation for 1 - 3 months, however our glucose reserves are exhausted after 1 day
In glucose synthesis from glucose-6-phosphate, glucose 6-phosphatase is activated by:
a) Ca++
b) Mg++
c) Na+
d) K+
b) Mg++
for the average person (70kg), liver glycogen lasts approximately __ hours
for the average person (70kg), liver glycogen lasts approximately 3 hours
Ethanol consumption leads to an accumulation of NADH, which leads to what 3 metabolic factors:
- inhibits gluconeogenesis (prevent oxidation of lactate to pyruvate) -> lactate accumulates
- inhibits fatty acid oxidation -> stimulates fatty acid synthesis in liver -> TAG accumulates -> fatty liver
- block the processing of acetyl-CoA by citric acid cycle, thus ketone bodies were generated in blood and pH drops.
during starvation, the human body’s second priority after providing sufficient glucose to the brain, is to:
preserve protein by shifting from utilization of glucose to utilization of fatty acids + ketone bodies
(Figure B)
In acid-base homeostasis, ketone bodies can cause ——–
Metabolic acidosis
(ketoacidosis)
What is the organ that consumes most glucose in the body?
a) Brain
b) Kidney
c) Liver
d) Lung
e) Pancreas
a) Brain
What is the net cost of phosphate in Cori Cycle?
4 pi
What are the dangers for other organs (excluding the brain) to use ketone bodies during a prolonged starvation state?
Ketone bodies are acidic = decreases blood pH = enzymes may not be able to function optimally (enzyme inhibition)
Glucose 6-phosphate is catalyzed with glucose 6-phosphatase yielding ——-
a) Fructose
b) Fructose 6-phosphate
c) Glucose
d) Glycogen
e) Lactose
c) Glucose
Glycogen is broken-down in the muscles to glucose-6-phosphate (G-6-P). However, G-6-P can’t be converted to glucose in the muscles due to lack of the enzyme ——–.
glucose-6-phosphatase
what 3 pathways are inhibited during a fed state?
Inhibition of:
- Gluconeogenesis
- Glycogenolysis
- Lipolysis
during a starvation state (hypoglycaemia), fatty acids can be oxidised to produce _____ ____ via lipolysis (beta oxidation), which is then sent to the _____ mitochondria to be converted into ______ ______ .
Because these are water soluble, they can be easily transported from the liver to other tissues to be re-converted to _____ ____ for energy production (TCA cycle)
during a starvation state (hypoglycaemia), fatty acids can be oxidised to produce Acetyl CoA via lipolysis (beta oxidation), which is then sent to the liver mitochondria to be converted into ketone bodies.
Because these are water soluble, they can be easily transported from the liver to other tissues to be re-converted to Acetyl CoA for energy production (via TCA cycle)
2?
Fructose 6-phosphate
up arrow = Gluconeogenesis,
down arrow = glycolysis
1?
Glucose 1-phosphate
(Glycogenolysis)
Gluconeogenesis releases energy, whereas glycolysis consumes energy.
a) True
b) False
a) False
gluconeogenesis consumes energy (endergonic)
glycolysis releases energy (exergonic - 96.2 kJ/mol)
Irreversible reactions during glycolysis must be bypassed during ———-
a) Hydrolysis
b) Gluconeogenesis
c) Glycogenesis
d) Phosphorylation
b) Gluconeogenesis
How does the human body regulate/inhibit glycolysis?
Once the human body has enough ATP (glycolysis pathway is no longer needed), the produced ATP will allosterically inhibit the enzymes responsible in glycolysis in step 1 (Hexokinase), step 3 (Phosphofructokinase/PFK-1) and step 10 (Pyruvate kinase) and thus saves the energy consumed in these steps
Which organ has the most important site for gluconeogenesis during starvation?
a) Brain
b) Kidney
c) Liver
d) Lung
e) Muscles
kidney
(provides 50% of blood glucose via GNG)
Which hormone do you expect to function in case of high concentration of plasma glucose? What do you call this process?
a) Glucagon, glycolysis
b) Glucagon, gluconeogenesis
c) Insulin, glycolysis
d) Insulin, gluconeogenesis
c) Insulin, glycolysis
Which organ has the most important site for gluconeogenesis during starvation?
kidneys
Brain and muscles don’t have glucose-6-phosphatase and accordingly they can’t synthesize glucose.
a) True
b) False
a) True
in the cori cycle, Lactate produced from ______ passes via the blood to the liver, where it may be converted to _______
in the cori cycle, Lactate produced from pyruvate passes via the blood to the liver, where it may be converted to glucose
Insulin stimulates all the following Except:
a) Gluconeogenesis
b) Glycogenesis
c) Glycolysis
d) Lipogenesis
e) Protein synthesis
a) Gluconeogenesis
(only catabolic pathway, insulin is anabolic)
8 - 24 hours without food is called the ____ ______ state
8 - 24 hours without food is called the early fasting state
The process whereby precursors such as lactate, pyruvate, and amino acids are converted to glucose is termed
a) Glycolysis
b) Glycogenesis
c) Glycogenolysis
d) Gluconeogenesis
d) Gluconeogenesis
During gluconeogenesis,
Glycogen is stored in——-
a) Brain and spleen
b) Liver and muscle
c) Liver and spleen
d) Pancreas and spleen
b) Liver and muscle
During glycolysis, step 1 & 3 lose __ ATP (1 ATP each), whereas step 10 makes __ ATP, so the overall will be ___ ATP
During glycolysis, step 1 & 3 lose 2 ATP (1 ATP each), whereas step 10 makes 4 ATP, so the overall (net) will be 2 ATP
Gluconeogenesis produces energy, whereas glycolysis consumes energy.
a) True
b) False
b) False
GNG consumes energy to increase plasma glucose
glycolysis produces energy from glucose (net 2 ATP & 2 NADH)
Name the pathway:
Muscles degrade to amino acids for energy which releases nitrogen. The nitrogen byproduct is transaminated by ALT (alanine aminotransferase) to pyruvate (product of glycolysis) to form alanine. This alanine is shuttled to the liver where the nitrogen bound to alanine is removed to enter the urea cycle and the pyruvate is used to make glucose.
This pathway is used instead of the Cori cycle only when an aminotransferase (ALT/AST) is present and when there is a need to transfer ammonia to the liver.
Alanine cycle or Cahill cycle
Glycogen is broken down in the muscle to glucose-6-phosphate (G6P). However, G6P can’t be converted to glucose due to a lack of:
a) ATP
b) NADH
c) Glucose-6-phosphatase
d) Glucose-1-phosphatase
Glycogen is broken down in the muscle to glucose-6-phosphate (G6P). However, G6P can’t be converted to glucose due to a lack of Glucose-6-phosphatase in the muscle
What is the organ that stores the most glycogen in the body?
a) Brain
b) Liver
c) Lung
d) Muscle
e) Pancreas
d) Muscle
In the human body, which fuel store can last for longer time?
a) Adipose fat
b) Liver glycogen
c) Muscle glycogen
d) Muscle protein
a) Adipose fat
which 3 pathways occur in a fasted state:
- Glycogenolysis (breakdown of glycogen to glucose, 12-24 hrs)
- Gluconeogenesis (synthesis of glucose from A.A., lactate, glycerol, etc)
- Lipolysis (breakdown of lipids)
14?
(pathway)
melvanoate pathway/cholesterol synthesis
15?
(pathway)
glycogenolysis
11?
(pathway)
TCA/krebs cycle
(CO2 is the eventual byproduct in this pathway)
The Cori Cycle operates during —-
a) Exercise
b) Sleeping
c) Thirst
a) Exercise
When fasting, muscle and liver tissue use _________ when blood glucose is low.
a) Fatty acids as a fuel then glycogen
b) Glycogen as a fuel then fatty acids
c) Glycogen as a fuel then glucose
d) Proteins as a fuel then glycogen
b) Glycogen as a fuel then fatty acids
(stimulated by glucagon)
Fasting requires all the glucose to be synthesized from ——– precursors?
a) Carbohydrate
b) Glucose
c) glycogen
d) Non-Carbohydrate
d) Non-Carbohydrate
How does the liver work during vigorous exercise? During vigorous exercise, the liver transforms lactate to glucose via —
a) Cahill cycle
b) Citric acid cycle
c) Cori cycle
d) Krebs cycle
e) Pyruvate cycle
c) Cori cycle
Where is glycerol most likely to be found in the body?
a) Adipose tissue
b) Muscle
c) RBCs
d) Erythrocytes
e) Heart
a) Adipose tissue
VLDL requires glucose to be stored in adipose tissues as ____________.
VLDL requires glucose to be stored in adipose tissues as TAG’s
When the glucose concentration goes above 30mM, —— is up-regulated to transport glucose to the plasma.
a) GLUT1
b) GLUT2
c) GLUT3
d) GLUT4
b) GLUT2
Cori cycle occurs during anaerobic time (e.g. exercise), where lactate is produced in RBCs and —–. Lactate is then goes to the —-where it gets converted to —–.
a) Adipose tissue
b) Muscle
c) Liver
d) Glucose
e) Glycogen
Cori cycle occurs during anaerobic time (e.g. exercise), where lactate is produced in RBCs and muscle. Lactate is then goes to the liver where it gets converted to Glucose.
In the Cori Cycle, how many phosphate ions are consumed? (net)
a) 1
b) 2
c) 3
d) 4
e) 6
d) 4
After fasting/hunger, all processes are catabolic/degradation of molecules except:
a) Lipolysis
b) Gluconeogenesis
c) Glycogenolysis
d) Glycolysis
b) Gluconeogenesis
———is characterized by loss of adipose tissue and skeletal muscle mass.
a) Diabetes
b) Arthritis
c) Cachexia
d) Diabetic
e) Glucoma
c) Cachexia
the 3 types ketone bodies are:
- Acetone
- Beta-hydroxybutyrate
- Acetoacetate
In diabetes mellitus, type I is characterized by _________, whereas type II is characterized by ___________
a) Deficiency of insulin, tissue resistance to insulin
b) High level of glucose, low level of glucose
c) Low level of glucose, high level of glucose
d) Tissue resistance to insulin, deficiency of insulin
In diabetes mellitus, type I is characterized by deficiency of insulin, whereas type II is characterized by tissue resistance to insulin
In the fasted/starvation state, _______________ cleaves TAG’s stored in adipose tissue to produce gycerol and fatty acids which are then sent to the liver to be used as fuel.
(lipolysis)
In the fasted/starvation state, hormone-sensitive lipase cleaves TAG’s stored in adipose tissue to produce gycerol and fatty acids which are then sent to the liver to be used as fuel.
(lipolysis)
In the citric acid cycle, _________ can be synthesized from alanine, pyruvate, asparagine and aspartate. On the other hand, it can produce acetyl-CoA and glucose.
(Gluconeogenesis)
In the citric acid cycle, oxaloacetate can be synthesized from alanine, pyruvate, asparagine and aspartate. On the other hand, it can produce acetyl-CoA and glucose.
(Gluconeogenesis)
When our body needs glucose, glucagon (hormone) stimulates ________ to hydrolyse the triglycerides to fatty acids and glycerol, then later can then be transformed to glucose in the _____ cells.
a) Adipose tissue
b) Muscle
c) Liver
d) Lipase
e) Hydrolase
When our body needs glucose, glucagon (hormone) stimulates lipase to hydrolyse the triglycerides to fatty acids and glycerol, then later can then be transformed to glucose in the liver cells.
_________ ______ synthesises, stores, and mobilses triacylglycerols
adipose tissue synthesises, stores, and mobilses triacylglycerols
Glucagon stimulates all of the following Except:
a) Gluconeogenesis
b) Glycogenolysis
c) Glycolysis
d) Lipolysis
c) Glycolysis
- glucagon is stimulated by a decreased blood glucose, so it will in turn stimulate pathways that increase blood glucose
After fasting, and when the body needs glucose, which of the following is most likely to occur?
a) Gluconeogenesis
b) Glycogenesis
c) Lipogenesis
d) Protein synthesis
a) Gluconeogenesis
In the Cori Cycle, lactate is produced in the ———– (organ) and it is converted to ———- (carbohydrate).
a) Muscle, glucose
b) Muscle, glycogen
c) Kidneys, glucose
d) Liver, glycogen
e) Liver, glucose
In the Cori Cycle, lactate is produced in the liver (organ) and it is converted to glucose (carbohydrate).
Glycerol is converted to Glycerol 3-phosphate by the enzyme ______ ______ ______
Glycerol is converted to Glycerol 3-phosphate by the enzyme Hepatic glycerol kinase
Normal blood glucose levels are between _____mmol/L.
- Above ___ mmol/L is called Hyperglycemia
- Below ___ mmol/L is called Hypoglycemia
Normal blood glucose levels are between 4.0-7.8 mmol/L.
- Above 7.8 mmol/L is called Hyperglycemia
- Below 4.0 mmol/L is called Hypoglycemia
synthesizing glucose from non-carbohydrate precursors is termed ——-
a) Glycolysis
b) Gluconeogenesis
c) Glycogenesis
d) Glycogenolysis
b) Gluconeogenesis
Which hormone do you expect to function in case of low concentration of plasma glucose? What do you call this process?
a) Glucagon, glycolysis
b) Glucagon, gluconeogenesis
c) Insulin, glycolysis
d) Insulin, gluconeogenesis
b) Glucagon, gluconeogenesis
1?
(pathway)
glycogenolysis, then glycolysis
9?
(pathway)
lipogenesis
(acetyl coa molecules and glycerol are bonded by enzymes to ‘build’ triacylglycerols)
2 hours after a meal is called the ___________ state
2 hours after a meal is called the postabsorptive state
Alcohol can be dangerous to your health. Ethanol can’t be fully excreted by the ______ and must be metabolized by the _____. Its excess can cause ______ damage.
a) Brain
b) Heart
c) Kidney
d) Liver
e) Pancreas
Alcohol can be dangerous to your health. Ethanol can’t be fully excreted by the kidneys and must be metabolized by the liver. Its excess can cause liver damage.
3?
6-phosphogluconate
(PPP)
Which hormone is most likely to be secreted during the fed state?
a) Glucagon
b) Growth hormone
c) Insulin
d) Oestrogen
c) Insulin
Glucagon and insulin were secreted by which of the following cells, respectively?
a) α-cells and β-cells
b) β-cells and α-cells
c) γ-cells and β-cells
d) α-cells and γ-cells
a) α-cells and β-cells
7?
(pathway)
Cahill/glucose-alanine cycle
toxic ammonia is transferred from alanine via alanine aminotransferase (ALT) to produce pyruvate in the liver, the ammonia is then disposed of via the urea cycle.
why cant muscle & brain cells carry out gluconeogenesis?
Because they doesn’t contain the enzyme glucose 6-phosphatase
4?
(pathway)
gluconeogenesis
Glycolysis produces —– ATP, whereas gluconeogenesis consumes —— ATP.
a) 2
b) 4
c) 6
d) 8
e) 32
Glycolysis produces 2 ATP, whereas gluconeogenesis consumes 6 ATP.
20?
(pathway)
gluconeogenesis
You’ve just finished a large meal (fed state), will Acetyl CoA be activated or inhibited?
activated
- increased blood glucose = increased insulin = activation of anabolic pathways.
- Acetyl CoA will be used for lipogenesis (conversion to malonyl CoA for fatty acid synthesis)
How many reactions must be bypassed during gluconeogenesis?
a) 1
b) 2
c) 3
d) 4
e) 5
3 steps (1, 3, 10)
(three kinases)
Glycogenesis is the formation of ——–
a) Glucose
b) Glycogen
c) Glucose 1-phosphate
d) Glucose 6-phosphate
b) Glycogen
the _______ secretes insulin (beta cells within the islets) and glucagon (alpha cells within the islets) in response to changes in blood glucose concentration.
the pancreas secretes insulin (beta cells within the islets) and glucagon (alpha cells within the islets) in response to changes in blood glucose concentration.
After a breakfast (re-fed state), which of the following hormones is most likely to increase?
a) Glucagon
b) Growth hormone
c) Insulin
d) Oestrogen
c) Insulin
the _____ ________ absorbs nutrients from the diet & moves them into the blood or lymphatic system
the small intestine absorbs nutrients from the diet & moves them into the blood or lymphatic system
the _____ transports ions to maintain membrane potential & integrates inputs from the body and surroundings. it also sends regulatory signals to other organs to determine which organ recieves fuel from where
the brain transports ions to maintain membrane potential & integrates inputs from the body and surroundings. it also sends regulatory signals to other organs to determine which organ recieves fuel from where
the ________ ______ carries lipids from the intestine to the liver
the lymphatic system carries lipids from the intestine to the liver
in a fasted state, does glucagon activate or inhibit acetyl CoA?
inhibit
- glucagon is a catabolic hormone which stimulates lipolysis fro fuel during a fasted state, thus preventing Acetyl CoA from being used in lipogenesis
Triacylglycerols are stored in the adipose tissue during a ______ state whereas they are released into the blood during a ______ state as free fatty acids (FFA) and glycerol
Triacylglycerols are stored in the adipose tissue during a fed state whereas they are released into the blood during a fasted/starvation state as free fatty acids (FFA) and glycerol
name the hormone:
- signals fed state
- stimulates storage of fuels and synthesis of proteins
- high level = glucose enters muscle + adipose tissue (synthesis of TAG
- stimulates glycogen synthesis in muscle + liver
- suppresses gluconeogenesis by the liver
- accelerates glycolysis in liver -> increases synthesis of fatty acids
- accelerates uptake of blood glucose into liver = glucose 6-phosphate more rapidly formed than level of blood glucose rises = built up of glycogen stores (glycogenesis)
Insulin
In a refed state, what would be the order of pathways?
a) Gluconeogenesis followed glycolysis
b) Glycolysis followed by glycogenesis
c) Glycogenesis followed by glycolysis
d) Glycolysis followed by Glycogenolysis
e) Glycolysis followed by gluconeogenesis
b) Glycolysis followed by glycogenesis
(lecture page is wrong)
16?
(pathway)
either glycogenesis, glycolysis or PPP
name the 3 stages of liver damage:
- development of fatty liver (inhibit liver functions)
- alcoholic/non alcoholic hepatitis (liver cell death)
- cirrhosis (urea cycle is inhibited = accumulation of toxic ammonia)
18?
(pathway)
glycogenesis
Which organ does all the following?
- Converts inactive Vit D3 (25(OH)-VitD3) to active VitD3 (1,25(OH)-VitD3)
- Filters blood plasma
- Produces urine
- Secrets wastes
- Responsible of gluconeogenesis during starvation
kidney
________ ______ is the body’s major source of TAG’s for fuel
Adipse tissue is the body’s major source of TAG’s for fuel
name the hormone:
- signals starved state
- mobilizes glycogen stores (Glycogenolysis)
- inhibits glycogen synthesis
- main target organ is liver
- inhibits fatty acid synthesis
- stimulates gluconeogenesis in liver
- large amount of glucose in liver released to blood stream -> maintain blood-glucose level
Glucagon
- stimulated by low blood glucose
- secreted by pancreatic alpha cells
After 3 days of starvation, the brain gets approximately ___% of its energy from ketone bodies
After 3 days of starvation, the brain gets 30% of its energy from ketone bodies
In the fed state, Glucose is converted to ______________ to bind with fatty acyl CoA’s to produce TAG’s which are then stored in adipose tissue.(lipogenesis)
In the fed state, Glucose is converted to Glycerol 3-phosphate to bind with fatty acyl CoA’s to produce TAG’s which are then stored in adipose tissue (lipogenesis)
for the average person (70kg), muscle glycogen lasts approxamitely ___ hours
for the average person (70kg), muscle glycogen lasts approxamitely 5 hours
When the glucose concentration goes above –—- mM, GLUT2 is up-regulated to transport glucose to the plasma.
a) 10
b) 20
c) 30
d) 40
e) 50
c) 30 mM
during starvation, the body will maintain blood-glucose levels above:
___ mg/100 ml
during starvation, the body will maintain blood-glucose levels above:
40 mg/100 ml
Cancerous cells became larger in size and consume more _______ (which leads to loss of adipose tissues and skeletal muscles). The tissues act as they are doing exercise, causing anaerobic conditions for the cells so they produce more _____ (a high concentration in blood can be a weak marker of cancerous cells)
Cancerous cells became larger in size and consume more glucose (which leads to loss of adipose tissues and skeletal muscles). The tissues act as they are doing exercise, causing anaerobic conditions for the cells so they produce more lactate (a high concentration in blood can be a weak marker of cancerous cells)
3?
(pathway)
gluconeogenesis
When the human body needs energy, the liver makes glucose through gluconeogenesis. Gluconeogenesis doesn’t fully follow the reverse steps of glycolysis and it bypasses steps 1, 3, 10 because their reverse reactions require
a) Glucose
b) Fructose
c) Glycogen
d) The most energy
e) Carbohydrates
d) The most energy
17?
(pathway)
glycogenolysis
What is the primary source of blood glucose in case of early fasting state?
a) Fructose
b) Glucose
c) Glycogen
d) Starch
c) Glycogen
- Brain
- nervous system
- erythrocytes
- testes
- renal medulla
- embryonic tissues
- can only utilize ______ _______ as their major or only energy source
plasma glucose
During starvation, when glucose is low in concentration, the ____ breaks down fatty acids to produce ______ ______ (acetone, acetoacetate and β-hydroxyl-butyrate).
During starvation, when glucose is low in concentration, the liver breaks down fatty acids to produce ketone bodies (acetone, acetoacetate and β-hydroxyl-butyrate).
The Cori cycle costs __ Phosphate ions in liver for every __ Phosphate ions made available in muscle. The net cost is __ Phosphate ions
The Cori cycle costs 6 Phosphate ions in liver for every 2 Phosphate ions made available in muscle. The net cost is 4Phosphate ions
During Glycogenesis, Glucose is converted to —— then to ——— then to glycogen
a) Glucose 1-phosphate
b) Glucose 2-phosphate
c) Glucose 3-phosphate
d) Glucose 6-phosphate
e) 6-Phospho gluconoate
During Glycogenesis, Glucose is converted to Glucose 6-phosphate then to Glucose 1-phosphate then to glycogen
_____ is major electron donor in reductive biosynthesis
NADPH is major electron donor in reductive biosynthesis
6?
(pathway)
Cahill/glucose-alanine cycle
(pyruvate is used to carry ammonia to the liver as the relatively inert alanine)
After eating a big meal (fed state), all processes are synthesis except:
a) Glycogenesis
b) Glycolysis
c) Lipogenesis
d) Protein synthesis
b) Glycolysis
The liver doesn’t have the enzyme _________________ aka ________ to transform acetyl CoA to energy (TCA cycle).
The liver doesn’t have the enzyme β-ketoacyl-CoA transferase aka thiophorase to transform acetyl CoA to energy (TCA cycle).
Between meals and during longer fasts, or after vigorous exercise, glycogen is depleted.
a) True
b) False
a) true
Glucagon generally elevates the concentration of glucose in the blood by promoting gluconeogenesis and _______
a) Glycolysis
b) Glycogenesis
c) Glycogenolysis
d) Lipogenesis
Glucagon generally elevates the concentration of glucose in the blood by promoting gluconeogenesis and Glycogenolysis
Dephosphorylating of glucose 6-phosphate yielding glucose is catalyzed by __________________
Dephosphorylating of glucose 6-phosphate yielding glucose is catalyzed by glucose 6-phosphatase
What is the glucose level in blood in mg/dL?
a) 30-100
b) 60-150
c) 100-150
d) 100-200
b) 60-150
Ethanol consumption leads to accumulation of high concentration of NADH, which inhibits ____________ by preventing the oxidation of lactate to pyruvate.
a) Gluconeogenesis
b) Glycolysis
c) Glycogenolysis
d) Glycogenesis
Ethanol consumption leads to accumulation of high concentration of NADH, which inhibits Gluconeogenesis by preventing the oxidation of lactate to pyruvate.
-this causes an accumulation of lactate
5?
(pathway)
cori cycle
(fate of pyruvate under anaerobic conditions in muscle & RBC)
In humans, two amino acids are exclusively ketogenic: ———–
a) Alanine and glycine
b) Leucine and isoleucine
c) Lysine and isoleucine
d) Leucine and lysine
e) Serine and threonine
b) Leucine and isoleucine
(L, I)
——- is the universal currency of energy in our body, whereas —- is a major electron donor in reductive biosynthesis.
a) ADP
b) ATP
c) NADPH
d) NAD+
ATP is the universal currency of energy in our body, whereas NADPH is a major electron donor in reductive biosynthesis.
eating after breakfast, to maintain blood glucose levels (lunchtime) is called the ______ state
eating after breakfast, to maintain blood glucose levels (lunchtime) is called the refed state
Ketone bodies circulating in the blood are picked up by cells and converted back into _____ ____ which then enters the citric acid cycle and is oxidized in the mitochondria for ______
Ketone bodies circulating in the blood are picked up by cells and converted back into Acetyl CoA which then enters the citric acid cycle and is oxidized in the mitochondria for energy
during lipolysis, fatty acids that are released into the bloodstream from adipose tissue cells are bound to transporter proteins called ________________ complexes
during lipolysis, fatty acids that are released into the bloodstream from adipose tissue cells are bound to transporter proteins called Fatty acid-albumin complexes
The liver plays an important role in producing ketone bodies, but it can’t use ketone bodies as a source of energy.
a) True
b) False
a) True
Muscle and brain tissue do not contain (glucose 6-phosphatase), and so cannot carry out ———
a) Gluconeogenesis
b) Glycolysis
c) Glycogenesis
d) Glycogenolysis
a) Gluconeogenesis
Diabetes mellitus, is characterized by __________, which is termed _________
a) High plasma glucose level, hypoglycaemia
b) High plasma glucose level, hyperglycemia
c) Low plasma glucose level, hyperglycemia
d) Low plasma glucose level, hypoglycemia
Diabetes mellitus, is characterized by high blood glucose, which is termed hyperglycaemia
In the Cahill cycle, blood transfers alanine from ————
a) Liver to muscle
b) Muscle to pancreas
c) Muscle to liver
d) Pancreas to liver
e) Liver to brain
c) Muscle to liver
2?
(pathway)
cori cycle
(liver)
