Biology Cell Membranes Quiz

<p>Carbohydrate (C)</p> Signup and view all the answers

<p>By shielding against low pH and degradative enzymes (B)</p> Signup and view all the answers

<p>Formation of the nuclear envelope (A)</p> Signup and view all the answers

<p>Regulates the permeability of cell membrane (D)</p> Signup and view all the answers

<p>Ganglioside GM1 (B)</p> Signup and view all the answers

<p>A diverse mix with flexibility (A)</p> Signup and view all the answers

<p>They assist in cell recognition and immune response. (B)</p> Signup and view all the answers

<p>They decrease fluidity by packing tightly together (B)</p> Signup and view all the answers

<p>They enhance membrane fluidity (A)</p> Signup and view all the answers

<p>It experiences a phase transition to fluid phase (D)</p> Signup and view all the answers

<p>The composition of the lipid tails (D)</p> Signup and view all the answers

<p>Different compositions on the inner and outer layers (D)</p> Signup and view all the answers

<p>Restrains phospholipid movement (A)</p> Signup and view all the answers

<p>To separate and protect the chemical components from the outside environment (D)</p> Signup and view all the answers

<p>Heads are hydrophilic while tails are hydrophobic (A)</p> Signup and view all the answers

<p>Small hydrophobic molecules (A)</p> Signup and view all the answers

<p>Cell membranes have a lipid bilayer and various proteins (B)</p> Signup and view all the answers

<p>Stimulates secretion of Chloride ions into the gut lumen. (D)</p> Signup and view all the answers

<p>N-glycosylation (D)</p> Signup and view all the answers

<p>Molecules that have both hydrophilic and hydrophobic properties (D)</p> Signup and view all the answers

<p>Regulate blood pressure. (B)</p> Signup and view all the answers

<p>Cholesterol (D)</p> Signup and view all the answers

<p>A preparation technique that splits membranes along the phospholipid bilayer (B)</p> Signup and view all the answers

<p>Hydroxyl group responsible for its polarity. (B)</p> Signup and view all the answers

<p>Ions and large hydrophilic molecules (B)</p> Signup and view all the answers

<p>They recognize pathogens by detecting antigens. (D)</p> Signup and view all the answers

<p>They are proteins with glycans attached to them. (B)</p> Signup and view all the answers

<p>They always trigger an immune response when detected. (A)</p> Signup and view all the answers

<p>Using a unique set of antigen receptors on lymphocytes. (B)</p> Signup and view all the answers

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.