cell wall

A cell wall is a rigid outer layer found in plant cells, fungi, bacteria, and some algae. It provides structural support, helping the cell maintain its shape and protect it from external stress. Unlike the cell membrane, which is flexible and controls what enters and exits the cell, the cell wall is tough and supportive. In plants, it is primarily made of cellulose, a strong carbohydrate. This external barrier allows the cell to withstand drought, physical forces, and provides a framework that helps the plant stand upright and grow properly.