How are carbohydrates related to the structure of cells?

Question

Chitin is embedded in cell walls to help move molecules into and out of the cell.
Chitin is embedded in cell walls to help move molecules into and out of the cell.

Monosaccharides make up fifty percent of the cell membrane, helping the cell maintain its shape.
Monosaccharides make up fifty percent of the cell membrane, helping the cell maintain its shape.

Glucose makes up the exoskeleton of insects, protecting them from the environment.
Glucose makes up the exoskeleton of insects, protecting them from the environment.

Cellulose makes up the cell wall in plants, helping the cell have a rigid outer layer.

Answer 1

Carbohydrates play several crucial roles in the structure and function of cells. Here's a breakdown of the statements you provided related to carbohydrates and their cellular roles:

1. Chitin: Chitin is a polysaccharide that forms the exoskeleton of arthropods (like insects) and is a key structural component of fungal cell walls. While it provides rigidity and protection, it is not primarily involved in the movement of molecules into and out of the cell; that function is mainly supported by membrane proteins and lipid bilayers.

2. Monosaccharides: This statement is incorrect. Monosaccharides (simple sugars like glucose) are not a structural component of the cell membrane in such a large percentage. Instead, carbohydrates attached to proteins and lipids (glycoproteins and glycolipids) in the cell membrane play roles in cell recognition and signaling, but they do not make up fifty percent of the membrane structure. The majority of the cell membrane is composed of phospholipids, along with proteins that assist in various functions.

3. Glucose: Glucose itself does not make up the exoskeleton of insects; rather, it is a monosaccharide that is utilized by organisms as an energy source. Chitin, which is a polymer derived from N-acetylglucosamine (an amino sugar), forms the structural component of the insect exoskeleton, providing protection and support.

4. Cellulose: This statement is correct. Cellulose is a polysaccharide composed of glucose units and forms the primary structural component of plant cell walls. It provides rigidity and strength to plant cells, allowing them to withstand turgor pressure and maintain their shape.

In summary, carbohydrates, particularly in the form of polysaccharides like chitin and cellulose, are essential for the structural integrity of cells. They contribute to the physical properties of cell walls in fungi and plants but are not major components of cell membranes. Monosaccharides like glucose serve primarily as energy sources rather than structural components.

Answer 2

which one is it?

Answer 3

Let's clarify the accuracy of each statement regarding the relationship between carbohydrates and cell structure:

1. Chitin is embedded in cell walls to help move molecules into and out of the cell.

   • Incorrect. Chitin is a structural component, primarily found in the exoskeletons of insects and the cell walls of fungi. It does not function to move molecules in and out of the cell.

2. Monosaccharides make up fifty percent of the cell membrane, helping the cell maintain its shape.

   • Incorrect. Monosaccharides do not make up such a large fraction of the cell membrane. Instead, glycoproteins and glycolipids (which involve carbohydrates) play roles in cell recognition and signaling, but the main structure of the cell membrane is composed of phospholipids and proteins.

3. Glucose makes up the exoskeleton of insects, protecting them from the environment.

   • Incorrect. Glucose itself does not comprise the exoskeleton. Instead, chitin (which is derived from N-acetylglucosamine, a derivative of glucose) makes up the exoskeleton of insects.

4. Cellulose makes up the cell wall in plants, helping the cell have a rigid outer layer.

   • Correct. Cellulose is indeed the primary component of plant cell walls, providing structural support and rigidity.

Summary:

The only correct statement is that cellulose makes up the cell wall in plants, helping the cell have a rigid outer layer. The other statements contain inaccuracies regarding the roles and functions of carbohydrates in cellular structure.