Metabolism of 100 grams of fat will yield approximately how many kilocalories?
**Core Concept**
Metabolism of fatty acids is a critical process in energy production, where fat is broken down to release energy in the form of kilocalories. This process involves the breakdown of triglycerides into fatty acids and glycerol, which are then further metabolized to produce energy.
**Why the Correct Answer is Right**
The metabolism of 1 gram of fat yields approximately 9 kilocalories. This is because fat is composed of fatty acids, which are broken down through beta-oxidation to produce acetyl-CoA. The acetyl-CoA is then fed into the citric acid cycle, where it produces ATP, NADH, and FADH2. These energy-rich molecules are then used to produce energy in the form of ATP. This process is highly efficient, with a yield of 9 kilocalories per gram of fat.
**Why Each Wrong Option is Incorrect**
**Option B:** This option is incorrect because it does not accurately reflect the energy yield of fat metabolism.
**Option C:** This option is incorrect because it is too high and does not take into account the efficiency of the metabolic process.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the energy yield of fat metabolism is approximately 9 kilocalories per gram, which is a critical concept in nutrition and energy balance.
**Correct Answer: C. 900 kilocalories.**