South African Bodybuilding and Fitness

South African Bodybuilding, Strength, and Fitness forum - "Knowledge is Confidence". We offer nutrition advice, health-and-fitness tools, a highly engaged and supportive fitness community, and resources that are 100% free. Our bodybuilding and fitness forum inspires, motivates, and supports our members to build healthy and sustainable habits. Far beyond just weight loss, MuscleTalk helps everyone learn to eat better and exercise regularly - for life.

An area dedicated to sharing the science and knowledge behind advanced diets and nutritional ideas.
#37
Sugars: Glucose and Fructose Relation to Glycogen Storage

Types of Sugars:
Glucose is one of the main sugar molecules found in various types of sugar. The sucrose found in table sugar and maple sugar is actually half glucose. Dextrose is 100 percent glucose. Although fructose is usually thought to be the main sugar in fruits, all fruits also contain varying proportion of glucose and sucrose. Both fructose and glucose are also found in high-fructose corn syrup, agave syrup and other sweeteners.

Glucose Metabolism
Once absorbed into your bloodstream, glucose does not necessarily have to be transported to your liver. Almost all of your cells, including the cells of your liver, muscles, brain and fat, can take some of the glucose circulating in your blood. Glucose can be used as a form of energy by most of your cells and converted to glycogen by your liver or muscles or converted to fat in your fat cells. Also, Glycogen storage capacity in man is approximately 15 g/kg body weight and can accommodate a gain of approximately 500 g before net lipid synthesis contributes to increasing body fat mass. Interestingly but not coincidental, in Lyle McDonald's book Rapid Fat Loss Hand Book, he recommends 15g-16g carbs per kg of lean body mass, assuming you're going into re-feeds completely glycogen depleted.

Fructose Metabolism
Fructose can only be processed by your liver. After absorbing fructose from fruits or a food sweetened with sugar, agave syrup or high-fructose corn syrup, fructose enters your bloodstream to be transported right to your liver. Part of this fructose can be converted into glucose by the liver to be stored as glycogen (approx. 100g), and the remaining portion is converted into triglycerides, a type of fat, by your liver.

Major metabolic pathways and flux of dietary glucose and fructose.
Image

We see that in order for Glucose to be converted into Glycogen it must under go (followed the numbering system in graphic):
1. Glucokinase is an enzyme that facilitates phosphorylation of glucose to glucose-6-phosphate.
2. Phosphoglucose isomerase is a dimeric enzyme that catalyses the reversible isomerization of glucose-6-phosphate and fructose-6-phosphate
5. Glycogen synthase is an enzyme involved in converting glucose to glycogen.

AND/OR

1. Glucokinase is an enzyme that facilitates phosphorylation of glucose to glucose-6-phosphate.
2. Phosphoglucose isomerase is a dimeric enzyme that catalyses the reversible isomerization of glucose-6-phosphate and fructose-6-phosphate.
6. Phosphofructokinase catalyses the phosphorylation of fructose-6-phosphate to fructose-1,6- bisphosphate.
7. Fructose-bisphosphate aldolase is an enzyme catalyzing a reversible reaction that splits the aldol, fructose 1,6-bisphosphate, into the triose phosphates dihydroxyacetone phosphate and glyceraldehyde 3-phosphate.
10. Pyruvate kinase is an enzyme involved in glycolysis. It catalyzes the transfer of a phosphate group (D-glyceraldehyde 3-phosphate) from phosphoenolpyruvate to ADP, yielding one molecule of pyruvate and one molecule of ATP.


From the graphic, you can see there are other products created from consuming glucose/fructose as well, just wanted to represent the conversion of glucose to glycogen and fructose to glycogen.

We see that in order for Fructose to be converted into Glycogen it must under go (followed the numbering system in graphic):
4.Fructokinase also known as D-fructokinase or D-fructose is an enzyme of the liver, intestine, and kidney cortex. The reaction equation is as follows: ATP + D-fructose = ADP + D-fructose 1-phosphate.
7.Aldolase A is an enzyme that catalyses a reversible aldol reaction: The substrate, fructose 1 phosphate is broken down into glyceraldehyde and dihydroxyacetone phosphate.
8.Triose-phosphate isomerase is an enzyme that catalyzes the reversible interconversion of the triose phosphate isomers dihydroxyacetone phosphate and D-glyceraldehyde 3-phosphate.
7. Aldolase A is an enzyme that catalyses a reversible aldol reaction: Dihydroxyacetone phosphate is broken down into fructose 1,6-bisphosphate and glyceraldehyde.
6. Fructose bisphosphatase (Fructose bisphosphatase catalyses the reverse of the reaction which is catalysed by phosphofructokinase) is an enzyme that converts fructose-1,6-bisphosphate to fructose 6-phosphate.
5. Glycogen synthase is an enzyme involved in converting glucose to glycogen.
12. A dehydrogenase is an enzyme that transfers a hydride from one molecule to another. Lactate dehydrogenase catalyzes the conversion of pyruvate to lactate and back.
The Cori cycle (also known as Lactic acid cycle), named after its discoverers, Carl Cori and Gerty Cori, refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose (and glucose can then be converted into glyocogen).

AND/OR

4.Fructokinase also known as D-fructokinase or D-fructose is an enzyme of the liver, intestine, and kidney cortex. The reaction equation is as follows: ATP + D-fructose = ADP + D-fructose 1-phosphate.
7.Aldolase A is an enzyme that catalyses a reversible aldol reaction: The substrate, fructose 1 phosphate is broken down into glyceraldehyde and dihydroxyacetone phosphate.
8.Triose-phosphate isomerase (TPI or TIM) is an enzyme (EC 5.3.1.1) that catalyzes the reversible interconversion of the triose phosphate isomers dihydroxyacetone phosphate and D-glyceraldehyde 3-phosphate.
10. Pyruvate kinase is an enzyme involved in glycolysis. It catalyzes the transfer of a phosphate group (D-glyceraldehyde 3-phosphate) from phosphoenolpyruvate to ADP, yielding one molecule of pyruvate and one molecule of ATP.
12. A dehydrogenase is an enzyme that transfers a hydride from one molecule to another. Lactate dehydrogenase catalyzes the conversion of pyruvate to lactate and back.
The Cori cycle (also known as Lactic acid cycle), named after its discoverers, Carl Cori and Gerty Cori, refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose (and glucose can then be converted into glycogen).

Conversion from Fructose to Glucose, Tracer Studies in Adults
Image
We can see that in the end (from research) fructose has a poor conversation rate (As seen in the table) through the processes described above of fructose converting to glycogen.

And as mentioned before (considering glucose storage/conversion to glycogen): Glycogen storage capacity in man is approximately 15 g/kg body weight and can accommodate a gain of approximately 500 g before net lipid synthesis contributes to increasing body fat mass. The process of converting glucose to glycogen is extremely efficient.

The other main products of consuming glucose and fructose are ATP and Lipoprotein. Discussed elsewhere (for now).

References:
http://healthyeating.sfgate.com/suga...cose-2090.html

http://physrev.physiology.org/conten.../1/23.full.pdf
http://ajcn.nutrition.org/content/48/2/240.abstract
http://www.nutritionandmetabolism.com/content/9/1/89

Most of the research presented comes from:
University of Lausanne, Lausanne, Switzerland
University of California
American Journal of Clinical Nutrition
Lyle McDonald
Pain Killer Pills For Sale

WHATSAPP/TEXT/CALL:+1(443) 281-3429 EMAIL:famketra[…]

http://www.globexdocumentations.com/buy-drivers-li[…]

Buy Firearms online,Buy Glock pistol online,Buy Gl[…]

Buy Nembutal online https://www.nembutalwarehouse.[…]