Question

click and drag on elements in order
place the steps of iron metabolism in order. start with iron intake at the top, and finish with absorption from the digestive tract at the bottom.
instructions
the stomach acid converts fe³⁺ to fe²⁺.
fe²⁺ binds to gastroferritin.
gastroferritin carries fe²⁺ to intestine for absorption.
a mixture of fe²⁺ and fe³⁺ is ingested.

Explanation:

Step1: Identify the start

The process starts with ingestion: "A mixture of $\text{Fe}^{2+}$ and $\text{Fe}^{3+}$ is ingested."

Step2: Stomach acid conversion

Next, stomach acid acts: "The stomach acid converts $\text{Fe}^{3+}$ to $\text{Fe}^{2+}$."

Step3: Binding to gastroferritin

Then, $\text{Fe}^{2+}$ binds: "$\text{Fe}^{2+}$ binds to gastroferritin."

Step4: Transport for absorption

Finally, transport to intestine: "Gastroferritin carries $\text{Fe}^{2+}$ to intestine for absorption."

Answer:

1. A mixture of $\text{Fe}^{2+}$ and $\text{Fe}^{3+}$ is ingested.
2. The stomach acid converts $\text{Fe}^{3+}$ to $\text{Fe}^{2+}$.
3. $\text{Fe}^{2+}$ binds to gastroferritin.
4. Gastroferritin carries $\text{Fe}^{2+}$ to intestine for absorption.