Science question?

Question

hey every one im claire and im home schooled im quite enjoying it i have been home schooled for less than a year im really struggling with this one question on my science assignment so please could people try and help me the question is that if a marathon runner eats a large amount of starchy carbohydrate the night before a race. describe the roles of insulin and glucagon within the runners body before and during the race hope some one will be able to help me because this is my last resort im struggling with it so much and cant find any help any where thanks for reading

claire x*x

Answer 1

punctuation would help, but that is neither here nor there.

http://en.wikipedia.org/wiki/Image:Insul...

http://en.wikipedia.org/wiki/Insulin

Those may help.

Glycogen synthesis is also stimulated by the insulin receptor via IRS-1. In this case, it is the SH2 domain of PI-3 kinase (PI-3K) that binds the P-Tyr of IRS-1. Now activated, PI-3K can convert the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2) to phosphatidylinositol 3,4,5-triphosphate (PIP3). This indirectly activates a protein kinase, PKB, via phosphorylation. PKB then phosphorylates several target proteins, including glycogen synthase kinase 3 (GSK-3). GSK-3 is responsible for phosphorylating (and thus deactivating) glycogen synthase. When GSK-3 is phosphorylated, it is deactivated, and prevented from deactivating glycogen synthase. In this roundabout manner, insulin increases glycogen synthesis.

http://en.wikipedia.org/wiki/Insulin_rec...

Actions of insulin on neurons

Insulin acts on all cells of the body. Although other cells can live on other fuels for a while, neurons are totally dependent on glucose as a source of energy. Thus, a lack of glucose first and most dramatically manifests itself in the functioning of the central nervous system. The phenomenon was once known as insulin shock, and is now called hypoglycemia or hypoglycemic coma. Because internal causes of insulin excess are extremly rare (insulinoma), the overwhelming majority of hypoglycemia cases are iatrogenic (caused by medical intervention). Two general classes of medication can cause hypoglycemia :

    * oral hypoglycemic agents

    * insulin in form of injection (subcutaneous, rarely intramuscular or intravenous)

http://nostalgia.wikipedia.org/wiki/Insu...

Regulatory actions of insulin on blood glucose levels

Despite long intervals between meals and the occasional consumption of meals with substantial carbohydrate load (e.g half a birthday cake), blood glucose levels normally remain within certain boundaries. This homeostatic process involves many actions but hormone regulation is the most important. There are two groups of antagonistic (contradictory) hormones :

    * hyperglycemic hormones (such as glucagon, growth hormone, and adrenaline), which increase blood sugar,

    * and only one hypoglycemic hormone (insulin), which decreases blood sugar.

This is because, at least in the short term, it is less harmful to have too much glucose in the blood than too little.

Beta cells in the islets of Langerhans have receptors that are sensitive to variations in blood glucose. If the level increases, more insulin from the stores is released and production intensified. When the level comes down to the physiologic value, the release stops. If the level of glucose drops dangerously low, hyperglycemic hormones come into play.

Actions of insulin on neurons

Insulin acts on all cells of the body. Although other cells can live on other fuels for a while, neurons are totally dependent on glucose as a source of energy. Thus, a lack of glucose first and most dramatically manifests itself in the functioning of the central nervous system. The phenomenon was once known as insulin shock, and is now called hypoglycemia or hypoglycemic coma. Because internal causes of insulin excess are extremly rare (insulinoma), the overwhelming majority of hypoglycemia cases are iatrogenic (caused by medical intervention). Two general classes of medication can cause hypoglycemia :

    * oral hypoglycemic agents

    * insulin in form of injection (subcutaneous, rarely intramuscular or intravenous)

It is a pretty intense interaction that was discovered less then 150 years ago.

Answer 2

From waht I know if it, most starchy carbs get stored as a percentage of fat, sometimes as much as 50% and the rest is used as instant sugar.

Sugar feeds the body cells, it it also burns them up so it must be coated, so to speak, with insulin to prevent burning body cells.

The avaerage person burns 2,000 calories a day at rest and a night meal and sleep can equal 10 or 12 hours which can equal 1,000 calories of instant sugar burn off and even call on reserves (fat).

Most runners in good shape don't have that much fat.

I'm talking, of course, olympic types.  They often have 9-11% fat (BMI) or about 1/3 of what a typical person in normal body size has.

Carbing up is generally a regime used by body builders.

I tend to think a nighttime carbing will just get the runner through to mid-morning.

They will need to infuse some instant sugar.

They will also need to infuse some Phosphates to help in the restorationg of ATP production.

ATP production is required to do work, such as running.

Read up on ATP production.

http://en.wikipedia.org/wiki/Adenosine_t...

The liver and pancrease work in tandement to send a stream of sugar and insulin into the body to feed the cells.  But to produce ATP more effectively some types of phosphates must also be included in the body chemistry.

This sugar is usually draw from the stomach and liver in the form of instant sugars (drinking, for example, orange juice earlier in the day or having cerial with fruit, your carbs which get stored partially as reserve sugar) and reserve sugars from fats.

That is how you lose weight by burning off fats, but most runners in good shape starve themselve (or purge themselves) of fats and often need to infuse fats in the form of olive oil on a daily basis.

Now you don't want to have food in your stomach before you run.  But after 8 hours most of the food you ate as burned off or been converted to some reserve sugar.

You don't specify a lot of mitigating factors here, like how many calories of starches were consumed, the BMI ratio of the runner and their cardio system.

Someone who runs a lot has a more efficent cardio system and burns sugars and fats more efficently.

From where I stand the best way to look at this is like a car.

You put gas in a car at night (carb up) but the car is left running in idle all night long so it burns up some of that gas or most of it.  In the morning that car is going to need more gas to get you to work.

That is, at least, the practical aspect.

You also don't specify when the marathon takes place time wise.

If it's early, I'd have the runner get up very early and eat a carby breakfast with some isntant sugars several hours before the event so the roughage is purged from the system by evacuation but not the sugars.

I'd also include some phosphates.

YOu want to feed the muscles with available sugar and provide some phosphates to help restore ATP production quickly.

There are quasi illegal substances (at least in a competition) that do this, such as Creatine, which is probably banned or frowned upon.

But there are other drinks with phosphates that no one takes an issue with.

You might want to also look up Creatine to see how it works in ATP production.

Creatine, it should be noted, doesn't do much for racers.  It's mostly for body builders.  But it IS an ATP hyper upper.

Now the process of consuming sugars and starches end up in the stomach and direct sugars such as Fructose can get absorbed almsot direclty into the body, other sugars such as table sugar need preocessing to turn it into glucose.

Once sugars go into the body insulin has to be released to keep the sugar from buring cells.

Insulin has a negative effect on calcification and as such introducing insuling in great proportions (which happens) decalcifies bones and teeth.  Bone become prone to breaking and teeth become prone to decay.

It is the insulin in the body.

Now when a person like this wakes up they have a more regulated insulin and sugar flow then when they ate their dinner.

When you eat, especially sugar-carbs, you get a sugar spike (glucose spike or gylcermic spike) that rasiese your body system way too high from a cardio vascular point of view.

The insulin goes in and attemps to calm this down.

It attempst to keep the sugar in the body under control and reduce it to a safe flow level to feed the body cells.

So by morning your runner has a balanced flow of sugar and insulin, but has used up a fair portion of the instant sugar and some reserves just producing ATP to keep their lungs moving during sleep.

The diaphragm and heart have been burning this sugar to keep ATP production going to pump the blood and circulate the air.

It is hard to say how much reserves were stored up from the carbs and how many were called upon by the body during the night.  A lot of this has to do with the amount of body fat the runner has intially.  Their BMI can play a significant factor, for a LOW BMI makes it very, very hard for the body to call upon the remaning fat cells for reserve sugar.

Now if the person has a modest BMI of 15 or 20% those reserve fats from the starches may provide some extra power for the day.