Biology: How does the liver contribute to homeostasis?

How does the liver help control body temperature? (GCSE purposes).

Thanks.

The liver is one of the largest internal organs of the body. It therefore dissipates a lot of heat energy.

True, but unlikely to gain many marks.

The liver is responsible for the conversion of fructose and galactose into glucose which can be used for cellular respiration. In addition, the liver can convert fat and protein into carbohydrates.

How does the liver help control body temperature? (GCSE purposes).

Thanks.

Mammals cannot convert lipid (fat) into carbohydrate

I think you're confused with the term "lipid(s)". Lipid is NOT defined as or is NOT JUST FAT, lipid can be correctly defined as any of a group of organic compounds, that are insoluble in water but soluble in nonpolar organic solvents. Applying this definition, lipids include, triglyceride, oils, and fats.

So, therefore I think fats can be converted into carbohydrate directly. I am not entirely sure if I'm right or not, and I may need to cross-check. Anyone else got any suggestions?

Oils and fats are triglycerides, just with differing amounts of saturation in their fatty acid chains. They are all the same thing - three fatty acid chains ester bonded to a glycerol molecule. Triglyceride (triacylglycerol, TAG) is NOT used in gluconeogenesis - I quote from my lecture notes "fatty acids are not glucogenic because mammals cannot convert acetyl CoA to glucose."

There are many many things in Biochemistry that I don't know (I couldn't describe gluconeogenesis from glycerol for you) but I do know that much.

In my defense, I may not have made things clear but I never imagined the fatty acid part of the triglyceride having anything to do with gluconeogenesis. I always thought the ester bonds were hydrolysed and glycerol was then phosphorylated and converted to glucose.

It is, but to say that lipids are converted to glucose is an easy way to get the examiner to take marks off you. Glycerol is only part of a lipid - the FAs are far more substantial. Sorry to be picky - it's just one of those things my Biology teacher (and lecturers here) taught me to love to hate!

Lol...don't worry, all that complicated stuff isn't required for GCSE. To simplify the above, the liver contributes to homeostasis by converting glucose in the blood to glycogen when the blood glucose levels are too high. When the blood glucose levels are too low, the liver converts glycogen back into glucose.

The liver works with the pancreas to carry this out. The pancreas secretes the hormone insulin into the blood stream, which tells the liver to stop the conversion of glucose into glycogen. This is when the blood sugar levels are too high. When the blood sugar levels are too low, the pancreas secretes glucagon into the blood stream, which tells the liver not to convert so much glucose into glucagon, and in fact make glycogen from glucose. And so the blood sugar levels can be kept constant using this rather cunning method. And that's how the liver contributes to homeostasis for GCSE, in case you were having a fit about what the hell "gluconeogenesis" was.

In response to the original question, I have no idea. Does it?

How does the liver help control body temperature? (GCSE purposes).

Thanks.

Guys, i think it is a popular belief that the liver generates heat through exothermic reactions that take place, but studies have shown that the temperature of the blood in the hepatic vein is the same as the temperature in the hepatic artery - save for the usual temperature difference between veins and arteries.

The question still really hasn't been answered. Is it not a little 'flat-earth'? I don't know, i'm probably the closest thing to ignorant here .