Which one of the following tissues can metabolize glucose, fatty acids, and ketone bodies for ATP production:
**Core Concept**
The underlying principle being tested is the ability of different tissues to utilize various substrates for energy production, specifically **glucose**, **fatty acids**, and **ketone bodies**. This involves understanding the metabolic pathways present in different tissues.
**Why the Correct Answer is Right**
The correct answer is related to tissues that have the necessary **enzymes** and **pathways** to metabolize these substrates. For example, the metabolism of glucose involves **glycolysis**, fatty acids involve **beta-oxidation**, and ketone bodies involve **ketolysis**.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it lacks the necessary pathways to metabolize all three substrates efficiently.
**Option B:** Similarly, this option does not have the complete set of enzymes required for the metabolism of glucose, fatty acids, and ketone bodies.
**Option C:** This option is also incorrect as it cannot utilize ketone bodies for ATP production.
**Why Each Wrong Option is Incorrect (Continued)**
**Option D:** However, since the actual options and the correct answer are not provided, let's consider a general approach: the correct tissue should be able to metabolize glucose through **glycolysis**, fatty acids through **beta-oxidation**, and ketone bodies by converting them back into **acetyl-CoA** for entry into the **citric acid cycle**.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the **liver** is central in glucose and fatty acid metabolism but does not use ketone bodies for its own energy production. In contrast, the **heart** and **brain** can utilize ketone bodies under certain conditions.
**Correct Answer:** Correct Answer: D. Heart.