Cell Membrane Function and Components Flashcard

Front

What is the main function of the cell membrane?

Back

To form a boundary between the cell and its environment

Answer explanation

The main function of the cell membrane is to form a boundary between the cell and its environment, regulating what enters and exits the cell, thus maintaining homeostasis.

Front

Component of a phospholipid: Amino acid, Nucleotide, Glycerol

Back

Glycerol

Answer explanation

Glycerol is a key component of phospholipids, serving as the backbone to which fatty acids are attached. Amino acids and nucleotides are not part of phospholipid structure.

Front

What role do cholesterol molecules play in the cell membrane?

Back

They strengthen the cell membrane

Answer explanation

Cholesterol molecules play a crucial role in strengthening the cell membrane by providing stability and fluidity, which helps maintain the integrity of the membrane structure.

Front

How do polar heads of phospholipids interact with water?

Back

They form hydrogen bonds with water

Answer explanation

The polar heads of phospholipids are hydrophilic, meaning they interact favorably with water by forming hydrogen bonds. This interaction helps to stabilize the structure of cell membranes.

Front

What is the function of carbohydrates attached to membrane proteins?

Back

To act as identification tags

Answer explanation

Carbohydrates attached to membrane proteins serve as identification tags, helping cells recognize each other and communicate. This is crucial for processes like immune response and tissue formation.

Front

What does the fluid-mosaic model describe?

Back

The arrangement of molecules in the cell membrane

Answer explanation

The fluid-mosaic model describes the arrangement of various molecules, including lipids and proteins, in the cell membrane, illustrating its dynamic and flexible nature.

Front

What property allows the cell membrane to let some materials cross but not others?

Back

Selective permeability

Answer explanation

The cell membrane's property of selective permeability allows it to control which substances can enter or exit the cell, ensuring that essential materials pass through while blocking harmful ones.

Front

What is the role of a receptor in cell communication?

Back

To detect a signal molecule and perform an action in response

Answer explanation

Receptors are proteins that detect specific signal molecules, such as hormones or neurotransmitters, and initiate a cellular response. This is crucial for cell communication, making the first answer choice correct.

Front

What type of molecules can cross the cell membrane and bind to an intracellular receptor?

Back

Nonpolar and relatively small molecules

Answer explanation

Nonpolar and relatively small molecules can easily cross the cell membrane due to their hydrophobic nature, allowing them to bind to intracellular receptors. In contrast, large polar molecules and ions cannot pass through the lipid bilayer.

Front

What happens when a receptor binds to a ligand?

Back

The receptor changes shape

Answer explanation

When a receptor binds to a ligand, it typically undergoes a conformational change, which can initiate a signaling cascade within the cell. This is crucial for cellular communication and response.