Biology Cell Membranes Quiz

A type of protein that has sugars attached to it.

A type of sugar chain that can be attached to lipids or proteins.

The process of attaching a glycan to a protein or lipid.

A type of glycosylation where a glycan is attached to the nitrogen atom of an asparagine amino acid.

A type of glycosylation where a glycan is attached to the oxygen atom of a serine or threonine amino acid.

Molecules found on the surface of pathogens that trigger an immune response.

A type of white blood cell that recognizes and responds to antigens.

Receptors on lymphocytes that bind to antigens.

A type of lipid crucial for cell membrane formation. It consists of two fatty acid tails (saturated or unsaturated), a glycerol backbone, a phosphate group, and a variable alcohol group (choline, ethanolamine, serine, or inositol).

Complex lipids found in cell membranes, especially in nervous tissue. They have a similar structure to phospholipids, but instead of a phosphate group, they have a sphingosine backbone.

A layer of carbohydrates on the cell surface, composed of glycolipids (carbohydrates + lipids) and glycoproteins (carbohydrates + proteins).

Glycolipids play a crucial role in cell-cell recognition, enabling cells to distinguish between each other. They are also involved in cell adhesion and signaling processes.

Glycolipids are important for cell adhesion, allowing cells to stick together and form tissues and organs.

Glycolipids play a vital role in cell signaling, acting as messengers that communicate information between cells.

Glycolipids can protect the cell membrane from harsh conditions, such as low pH and degradative enzymes.

Glycolipids can act as entry points for certain bacterial toxins and viruses. For example, the ganglioside GM1 is the receptor for cholera toxin.

A specialized technique that splits a membrane along the middle of the phospholipid bilayer, allowing for visualization of the membrane's internal structure.

The fundamental building block of all membranes, composed of two layers of phospholipids.

The ability of a membrane to maintain its fluidity, allowing for movement and flexibility.

The uneven distribution of lipids on the two sides of a membrane, creating a functional asymmetry.

Molecules with both hydrophilic (water-loving) and hydrophobic (water-fearing) properties.

Lipids bound to carbohydrates, found in cell membranes and involved in cell recognition and communication.

A steroid lipid found primarily in animal cell membranes, influencing membrane fluidity and stability.

Cholesterol is a lipid molecule that regulates the fluidity and permeability of cell membranes.

The fluidity of a cell membrane refers to the ability of its components (phospholipids and proteins) to move around within the membrane.

The asymmetry of a cell membrane means that the inner and outer surfaces of the membrane have different compositions and properties.

The fluid mosaic model describes the plasma membrane as a mosaic of components, including phospholipids, proteins, cholesterol, and carbohydrates. These components can move around freely within the membrane, giving it a fluid-like character.

Saturated hydrocarbon tails are straight and pack tightly together, making the membrane less fluid.

Unsaturated hydrocarbon tails have kinks, which prevents them from packing tightly, making the membrane more fluid.

Cholesterol acts as a fluidity buffer in animal cell membranes. It helps to restrain the movement of phospholipids at high temperatures, preventing the membrane from becoming too fluid, and it helps to prevent the membrane from becoming too rigid at low temperatures.

Depending on its composition and temperature, a lipid bilayer can exist in a gel phase or a fluid phase. In the gel phase, molecules are tightly packed and don't move much. In the fluid phase, molecules can move around more freely. Heating can cause a transition from the gel to fluid phase.