Question

Free fatty acids (FFAs) and triacylglycerides (TAGs)

Results for Dave: 500 mg/dL FFAs (normal range: 190-420 mg/dL); 190 mg/dL TAGs (normal range: 40-150 mg/dL)

Results for Michael: 660 mg/dL FFAs (normal range: 190-420 mg/dL); 230 mg/dL TAGs (normal range: 40-150 mg/dL)

Glucose and glycosylated hemoglobin (HbA_1c as a marker)

Results for Dave: [Glc] = 39 mg/dL (normal range: 70-110 mg/dL) Note: This value indicates severe hypoglycemia; HbA_1c = 4.4% (normal range: 4 – 6.5%)

Results for Michael: [Glc] = 31 mg/dL (normal range: 70-110 mg/dL) Note: This value indicates severe hypoglycemia; HbA_1c = 3.2% (normal range: 4 – 6.5%) (Note: You may wish to read about glycosylated hemoglobin)

When a typical person runs a marathon, they do not become severely hypoglycemic to the extent that either Michael or Dave did. Some people consume carbohydrates during the race in the form of foods, gels or sports drinks that have added sugar. However, even when dietary carbohydrates are not consumed during the race, how does the body of a healthy individual maintain adequate levels of blood glucose during sustained aerobic exercise? (Select ALL that apply!) Hint: You may wish to review about glycogen, ketone bodies, and amino acid degradation before attempting this question!

		Most blood glucose will come from the breakdown of liver glycogen (glycogenolysis) and the export of this glucose from the liver to the blood
		Ketone bodies are produced by adipocytes and converted into glucose by the liver
		Even-numbered fatty acids are catabolized and the carbon is used for gluconeogenesis in the liver
		Glucogenic amino acids are deaminated and the carbon skeletons used to synthesize glucose
		Most blood glucose will come from the breakdown of brain glycogen (glycogenolysis) and the export of this glucose from brain to the blood
		Muscles run gluconeogenesis and export glucose into blood
		The exclusively ketogenic amino acids (leucine and lysine) are deaminated and the carbon skeletons used to synthesize glucose
		Muscles convert lactate back into glucose and export this glucose back out into the blood

Answer 1

a)Ketone bodies are produced by adipocytes and converted into glucose by the liver

b)Muscles run gluconeogenesis and export glucose into blood

c)Muscles convert lactate back into glucose and export this glucose back out into the blood

Answer 2

Answer:- The correct options are:-1"2"3'6

Most blood glucose will come from the breakdown of liver glycogen (glycogenolysis) and the export of this glucose from the liver to the blood.

Ketone bodies are produced by adipocytes and converted into glucose by the liver

Even-numbered fatty acids are catabolized and the carbon is used for gluconeogenesis in the liver

Muscles run gluconeogenesis and export glucose into blood

Answer 3

However, even when dietary carbohydrates are not consumed during the race, how does the body of a healthy individual maintain adequate levels of blood glucose during sustained aerobic exercise? (Select ALL that apply!)

		Most blood glucose will come from the breakdown of liver glycogen (glycogenolysis) and the export of this glucose from the liver to the blood-------------correct
		Ketone bodies are produced by adipocytes and converted into glucose by the liver-------------correct
		Even-numbered fatty acids are catabolized and the carbon is used for gluconeogenesis in the liver-------------------correct
		Glucogenic amino acids are deaminated and the carbon skeletons used to synthesize glucose------correct
		Most blood glucose will come from the breakdown of brain glycogen (glycogenolysis) and the export of this glucose from brain to the blood-------false
		Muscles run gluconeogenesis and export glucose into blood-------- correct
		The exclusively ketogenic amino acids (leucine and lysine) are deaminated and the carbon skeletons used to synthesize glucose-------false
		Muscles convert lactate back into glucose and export this glucose back out into the blood- --------correct

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Gluconeogenesis : it is a metabolic pathway that outcomes in the generation of glucose from certain non-sugar carbon substrates. From breakdown of proteins, these substrates incorporate glucogenic amino acids (in spite of the fact that not ketogenic amino acids); from breakdown of lipids, (for example, triglycerides), they incorporate glycerol (in spite of the fact that not unsaturated fats); and from different strides in digestion system they incorporate pyruvate and lactate.

Gluconeogenesis is one of a few principle systems utilized by people and numerous different creatures to keep up blood glucose levels, staying away from low levels (hypoglycemia). Different means incorporate the corruption of glycogen (glycogenolysis), unsaturated fat breakdown.

Gluconeogenesis is a universal procedure, introduce in plants, creatures, growths, microscopic organisms, and different microorganisms. In vertebrates, gluconeogenesis happens essentially in the liver and, to a lesser degree, in the cortex of the kidneys. In ruminants, this has a tendency to be a consistent procedure. In numerous different creatures, the procedure happens amid times of fasting, starvation, low-starch diets, or extraordinary work out. The procedure is exceedingly endergonic until it is coupled to the hydrolysis of ATP or GTP, adequately making the procedure exergonic. For instance, the pathway driving from pyruvate to glucose-6-phosphate requires 4 atoms of ATP and 2 particles of GTP to continue suddenly. Gluconeogenesis is frequently connected with ketosis. Gluconeogenesis is additionally an objective of treatment for sort 2 diabetes, for example, the antidiabetic sedate, metformin, which restrains glucose development and empowers glucose take-up by cells.

Answer 4

Carbohydrates are sugar-based molecules, and the body can use it to produce glucose. Glucose will become stored within the liver and muscle as glycogen.These are molecules for long-time energy storage that may be used when needed.

The liver requires energy and convert the protein to glucose. The energy comes from fats. As the liver breaks down the fats for gluconeogenesis to occur,the conversion of protein to sugar, it produces ketones as a byproduct. Ketones are essentially water soluble , fat which can be a used as energy source for lots tissues which include the muscle tissues, mind and coronary heart. ketones act as a sugar within the brain.Gluconeogenesis reverses both glycolysis and fermentation by way of converting lactate first into pyruvate, and eventually back to glucose.

So we conclude that all are correct.

Answer 5

Answer:

(a) Most blood glucose will come from the breakdown of liver glycogen (glycogenolysis) and the export of this glucose from the liver to the blood.

(b) Ketone bodies are produced by adipocytes and converted into glucose by the liver.

(d) Glucogenic amino acids are deaminated and the carbon skeletons used to synthesize glucose.

Odd carbon fatty acids can be converted to glucose in mammals. In contrast, there is no net conversion of even-carbon fatty acids into glucose by mammals because such fatty acids yield only acetylCoA on oxidative cleavage. Acetyl-CoA cannot be used as a precursor of glucose by mammals.

G6Pase is absent from muscles. This is because, muscle does not export glucose. The liver, on the other hand, does export glucose and thus has abundant supplies of the enzyme.

Brain, like muscle, lacks glucose 6-phosphatase, and so it does not export glucose.

Ketogenic amino acids doesnot form glucose. Only glucogenic amino acids can get converted to glucose.

Answer 6

The correct options are

• Most blood glucose will come from the breakdown of liver glycogen (glycogenolysis) and the export of this glucose from the liver to the blood.
• Glucogenic amino acids are deaminated and the carbon skeletons used to synthesize glucose
• Muscles convert lactate back into glucose and export this glucose back out into the blood.

Reason

• Ketone bodies are produced by adipocytes but liver does not convert this ketone bodies to glucose. as it lacks the enzyme for conversion. so it is taken up by mitochondria and converted to oxaloacetate and inturn take up by citric acid cycle for energy.
• Fattyacids produce acetyl coa which cannot be used as carbon source directly .
• Most glucose of blood is produced by liver by glycongenolysis.
• The ketogeneic aminoacids are not involved in glucose production. Only glucogenic aminoacids are involved.
• Gluconeogenesis is performed by liver or kidneys.

Answer 7

During rest and excercise blood glucose will come from breakdown of glycogen. This glucose will come from liver to blood.

Only odd number fatty acid act as a substrate for gluconeogenesis in liver not even number fatty acids.

Ketone bodies are produced by the hepatocytes and it is not converted to glucose but it is utilized outside the liver for generation of energy.

Glucogenic amino acids deaminated abd synthesize glucose means first form intermediates of tca cycle then converted to glucose.

Ketogenic amino acids are deaminated to form a ketone bodies instead of glucose.

So mainly blood glucose maintained via glycogen degradation and from glucogenic amino acid and from odd number fatty acids

Muscles run gluconeogenesis and export glucose in blood, this process is not applicable here, it occur in anerobic condition, when in muscles , lactate converted to glucose and export out into blood.

Muscles convert lactate back into glucose and export back into the blood , it is a anaerobic process so here in aerobic excersise not applicable.

Answer 8

It is important to note that when performing low intensity exercise muscles have the required energy store to perform them. However once a high intensity exercise is involved for example running a marathon or performing an aerobic exercise body depends on other sources of glucose.

• Liver is an important storage organ of glucose (in the form of glycogen)so when the body is performing a high intensity exercise without any external source of glucose provided either through a sport drink, etc this source of glucose to the blood stream is delivered by a process called as glycogenolysis which is done through by the liver.
• Ketone bodies are produced when performing high intensity exercise especially when a person is low on carbohydrate intake as adipose cells provide a high level of energy.
• During high intensity exercise muscle tissue is degraded into amino acids and the carbon skeletons are used as energy source. Muscles perform this function by release of alanine which is absorbed by liver which is deaminated to form pyruvate which is then converted to glucose by gluconeogenesis.
• It is important to note that a trained healthy individual who is performing high intensity exercise like marathon running will have high amount of stored glycogen and also that his energy source will derived from glycogen and adipose tissue and muscle tissue in an almost equal distribution.

Answer 9

These are the correct sentences:

1. Muscles convert lactate back into glucose and export this glucose back out into the blood.

2. Muscles run gluconeogenesis and export glucose into blood.

3. Most blood glucose will come from the breakdown of liver glycogen (glycogenolysis) and the export of this glucose from the liver to the blood.