Animal Cells
Animal cells do not have cell walls. Instead they have a membrane that is made up of a lipid bilayer. In addition, they have an ECM (extracellular matrix) made of glycoproteins and collagen. They are important for cell to cell signal transduction.
There are three types of cell junctions:
1. Tight Junctions- two cell membranes are fused by integral membrane proteins to prevent fluid movement of any solute through the space (layer of cells). For example, epithelial cells in the stomach do not allow food particles to randomly go inside the body except through these specific proteins.
2. Gap Junctions- Channels through which chemical signals or solutes can pass from one cell to another. It is important for cell to cell communication. An example of this is that it allows small molecules to pass through.
3. Desmosomes- two cells are connected by keratin-like fibrous proteins. They are not as tightly sealed and act as an anchoring junction. Desmosomes also contain intermediate filaments
There are three types of cell junctions:
1. Tight Junctions- two cell membranes are fused by integral membrane proteins to prevent fluid movement of any solute through the space (layer of cells). For example, epithelial cells in the stomach do not allow food particles to randomly go inside the body except through these specific proteins.
2. Gap Junctions- Channels through which chemical signals or solutes can pass from one cell to another. It is important for cell to cell communication. An example of this is that it allows small molecules to pass through.
3. Desmosomes- two cells are connected by keratin-like fibrous proteins. They are not as tightly sealed and act as an anchoring junction. Desmosomes also contain intermediate filaments