From Dr. Greg Ellis in response to a question about fat and cho metabolism,
Now pyruvate via pyruvate dehydrogenase goes to acetyl CoA and fatty acids also go to acetyl. So now what do we have? We have Regulation in Metabolism. Under the influence of high rates of glycolyis (making glucose into acetyl CoA) the insulin: glucagon ration increases and the acetyl is diverted from the mitochindria where it would be used for energy and the enzyme acetyl CoA carboxylase is turned on and it converts the acetyl to malonyl-CoA which is the first committed step in converting carbohydrate-derived acetyl to saturated human fat. (Goes on in liver and adipose tissue). That's answer number 1 that our young pseudo-scientists even with an open book exam have not gotten in three days. I guesss I've made my point.
Now, if acetyl comes from fat, it enters the mitochondria and it is used as the driving source of fuel in the TCA cycle. Any excess acetyl from rapid fat delivery to the cell goes to ketones which are released to the blood where they can be oxidized by the peripheral tissues. Of course, little is known about this since ketones have received such a bad rap.
Carnitinepalmitoyl transferase I (CPT I) (the answer to #2) is the rate limiting enzyme in allowing acetyl to go into the mitochondria and is inhibited by malonyl-CoA. Glucose goes to malonyl and to fat, shutting down burning of itself and fat and it all gets stored as fat whereas fat delivery is burned. Pretty cool. If fat is making acetyl, its by-products at several locations slow down glycolysis (the break down of glucose). This is called the glucose-fatty acid cycle and therefore fat-burning controls carbohydrate burning.
How to drive fat burning? Eat fat and exercise. The absolute controller appears to be Sustrate Supply with all the other controls falling underneath and beholden to it. So eat carbs, use them, convert them to acetyl which goes to fat. That's how it works.
The phosphate/creatine system will do fine and its only worth about ten seconds of fuel anyway so don't worry about it.
The point is: the organism is designed to use and burn fat and if given a chance it will do it all day and that process will optimize every other part of the system.
All of my recommendations are based on this well-known schema. When you have the FACTS it becomes easy to design the plan.
Greg Ellis
Now pyruvate via pyruvate dehydrogenase goes to acetyl CoA and fatty acids also go to acetyl. So now what do we have? We have Regulation in Metabolism. Under the influence of high rates of glycolyis (making glucose into acetyl CoA) the insulin: glucagon ration increases and the acetyl is diverted from the mitochindria where it would be used for energy and the enzyme acetyl CoA carboxylase is turned on and it converts the acetyl to malonyl-CoA which is the first committed step in converting carbohydrate-derived acetyl to saturated human fat. (Goes on in liver and adipose tissue). That's answer number 1 that our young pseudo-scientists even with an open book exam have not gotten in three days. I guesss I've made my point.
Now, if acetyl comes from fat, it enters the mitochondria and it is used as the driving source of fuel in the TCA cycle. Any excess acetyl from rapid fat delivery to the cell goes to ketones which are released to the blood where they can be oxidized by the peripheral tissues. Of course, little is known about this since ketones have received such a bad rap.
Carnitinepalmitoyl transferase I (CPT I) (the answer to #2) is the rate limiting enzyme in allowing acetyl to go into the mitochondria and is inhibited by malonyl-CoA. Glucose goes to malonyl and to fat, shutting down burning of itself and fat and it all gets stored as fat whereas fat delivery is burned. Pretty cool. If fat is making acetyl, its by-products at several locations slow down glycolysis (the break down of glucose). This is called the glucose-fatty acid cycle and therefore fat-burning controls carbohydrate burning.
How to drive fat burning? Eat fat and exercise. The absolute controller appears to be Sustrate Supply with all the other controls falling underneath and beholden to it. So eat carbs, use them, convert them to acetyl which goes to fat. That's how it works.
The phosphate/creatine system will do fine and its only worth about ten seconds of fuel anyway so don't worry about it.
The point is: the organism is designed to use and burn fat and if given a chance it will do it all day and that process will optimize every other part of the system.
All of my recommendations are based on this well-known schema. When you have the FACTS it becomes easy to design the plan.
Greg Ellis