Which of the following does not contain metal

Options

A. Glycoproteins
B. Ferritin
C. Cytochromes
D. Chromoproteins

Answer

To determine which of the following options does not contain metals, we will analyze each option provided:

1. **Glycoproteins**:
- Glycoproteins are composed of proteins that have carbohydrate chains (oligosaccharides) attached to them. They do not contain any metal ions as part of their structure. Therefore, glycoproteins do not contain metals.

2. **Ferritin**:
- Ferritin is a protein that stores iron in a soluble and non-toxic form. It is specifically known for containing iron, which is a metal. Therefore, ferritin does contain metals.

3. **Cytochromes**:
- Cytochromes are proteins that play a key role in electron transport and contain heme groups, which include iron as a central atom. Thus, cytochromes also contain metals.

4. **Chromoproteins**:
- Chromoproteins are proteins that have a pigment and can bind to metal ions. An example is hemoglobin, which contains iron. Therefore, chromoproteins also contain metals.

Based on the analysis of each option, we conclude that the correct answer is:

**Answer: Glycoproteins do not contain metals.**

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