Question

Which of the following statements about food storage in the body is correct?

• A. More glycogen is stored per unit mass in the muscles than in the liver
• B. Glycogen storage in the liver is unlimited
• C. Fat is a more efficient form of fuel storage than glycogen
• D. Proteins in muscle cells are a normal storage form of fuel

Answer 1

The correct option is C Fat is a more efficient form of fuel storage than glycogen

More glycogen is stored per unit mass of liver than per unit mass of muscle. However since humans have a greater muscle mass than liver mass, there is more glycogen stored in the muscle than in the liver. The polymerisation of glucose to form glycogen reduces its osmotic pressure but its storage in the liver is limited. In fasting the liver glycogen stores are exhausted in about 24 hours.
Fat (triacylglycerol) storage appears to be unlimited. Fat is not hydrated and is hydrophobic and insoluble. It is also more reduced than glycogen. It stores more energy per unit weight than does glycogen. There is no real protein storage. Dietary amino acids are utilised to make tissue proteins such as enzymes and neurotransmitters, but there is no form of storage as there is for glucose and fat.