Okay, let's tackle this question about glucokinase. The question is asking for the statement that is NOT true about glucokinase. First, I need to recall what glucokinase does and its characteristics.

Glucokinase is an enzyme involved in glucose metabolism. I remember it's mainly found in the liver and pancreas. Unlike hexokinase, which is in other tissues, glucokinase has a higher Km for glucose, meaning it works better at higher glucose concentrations. That's why it's important in the liver for processing glucose after a meal.

The options are A to D, but they aren't provided. Wait, the user didn't list the options, which is a problem. Without seeing the options, it's tricky to explain why each is wrong. But maybe the correct answer is something common that's a misconception. For example, a common wrong statement might be that glucokinase is inhibited by glucose 6-phosphate, but actually, hexokinase is inhibited by that. Or maybe someone might think glucokinase is present in all cells, but it's only in specific tissues.

Another possible incorrect statement could be about the role in insulin secretion. Glucokinase in pancreatic beta cells helps sense glucose levels, so if a statement says it's not involved in that, that's wrong. Alternatively, if an option claims it's the same as hexokinase in all aspects except tissue distribution, that's incorrect because they have different Km and regulatory mechanisms.

The clinical pearl here is that mutations in glucokinase can cause MODY (Maturity Onset Diabetes of the Young), which is a key point for exams. Also, the high Km allows the liver to take up glucose only when levels are high, which is important for regulating blood sugar.

So if the correct answer is an option that says glucokinase is inhibited by glucose 6-phosphate, that's the exception. Because glucokinase isn't inhibited by its product, unlike hexokinase. So that's the false statement.

**Core Concept**
Glucokinase is a hexokinase isoform primarily expressed in liver and pancreatic β-cells. It catalyzes the phosphorylation of glucose to glucose-6-phosphate and has a high **Km** for glucose (~10 mM), allowing it to function only when blood glucose is elevated (e.g., postprandially). It is **not inhibited by glucose-6-phosphate**, unlike other hexokinases.

**Why the Correct Answer is Right**
The false statement is likely about glucokinase being inhibited by glucose-6-phosphate. **Hexokinase I-III** are inhibited by their product (glucose-6-phosphate), but **glucokinase lacks this feedback inhibition**. This allows the liver to continue phosphorylating glucose even when glucose-6-phosphate accumulates, ensuring glucose uptake for storage as glycogen or conversion to fat.

**Why Each Wrong Option is Incorrect**
**Option A:** *If it states glucokinase is present in pancreatic β-cells* – This is correct. Glucokinase acts as a glucose sensor in β-cells, triggering insulin release when glucose is high.
**Option B:** *If it claims glucokinase has a lower Km than hexokinase* – Incorrect. Glucokinase has a **much higher Km (10 mM vs. 0.1 mM)**

✓ Correct Answer: D. G-6-P inhibits it