Cell Size and Membranes – AP Biology Flashcard

Refers to the physical dimensions of a cell, typically measured in micrometers.

Generally range from 0.1 to 5.0 micrometers in diameter.

Typically range from 10 to 100 micrometers in diameter.

Includes metabolic requirements, nutrient availability, and surface area-to-volume ratio.

Influences cell function, efficiency, and the ability to exchange materials with the environment.

Commonly measured using a microscope and micrometric scale.

Ostrich egg cell, which can be up to 15 centimeters in diameter.

Mycoplasma, a type of bacteria, measuring about 0.2 micrometers in diameter.

Smaller cells have a larger surface area relative to their volume, facilitating nutrient exchange.

Larger cells may have slower metabolic rates due to decreased surface area-to-volume ratio.

A biological membrane that separates and protects the interior of a cell from the external environment.

Composed of a phospholipid bilayer, proteins, cholesterol, and carbohydrates.

Regulates the movement of substances in and out of the cell; maintains homeostasis.

Consists of hydrophilic heads facing outward and hydrophobic tails facing inward.

Involved in transport, signal transduction, and acting as enzymes or receptors.

Maintains membrane fluidity and stability, preventing the membrane from becoming too rigid or too fluid.

Attached to proteins or lipids, they play a role in cell recognition and communication.

Integral proteins (spanning the membrane) and peripheral proteins (attached to the surface).

Facilitate the movement of substances across the membrane.

Bind specific molecules (ligands) to trigger cellular responses.

The ability of the plasma membrane to allow substances to pass through it.

Size, charge, and polarity of molecules; temperature; and membrane fluidity.

Allows certain substances to pass while restricting others, crucial for homeostasis.

Small, nonpolar molecules like oxygen and carbon dioxide can easily pass through.

Large, polar molecules like glucose cannot easily cross the plasma membrane.

Passive transport requires no energy; active transport requires energy (ATP) to move substances against their concentration gradient.

Includes simple diffusion, facilitated diffusion, and osmosis.

The diffusion of water molecules through a selectively permeable membrane.

Involves pumps (e.g., sodium-potassium pump) and vesicular transport (endocytosis/exocytosis).

Theoretical frameworks that describe the structure and function of the cell membrane.

Describes the plasma membrane as a fluid combination of phospholipids, cholesterol, and proteins.

Accounts for the dynamic and flexible nature of the cell membrane, allowing movement and functionality of components.

Experiments such as freeze-fracture techniques and fluorescent labeling of membrane proteins.

Essential for protein mobility, membrane fusion, and cell signaling.

Include amphipathic properties, meaning they have both hydrophilic and hydrophobic regions.

Involved in cell recognition and signaling; play a key role in immune response.

Contribute to cell recognition and provide stability to the cell membrane.

Include channel proteins and carrier proteins, which assist in the movement of substances.

Allow specific ions to pass through the membrane, crucial for nerve impulse transmission.

Electrical potential difference across the membrane, important for nerve and muscle function.

The process by which cells internalize substances by engulfing them in a vesicle.

The process by which cells expel substances by fusing vesicles with the plasma membrane.

Dynamic and adaptable, varying in lipid and protein composition depending on the cell type.

Regions within the membrane with distinct protein and lipid compositions, playing roles in signaling and transport.

Involves receptors on the membrane interacting with ligands to trigger cellular responses.

Mediate communication between cells and their environment, essential for cellular functions.

The difference in electrical charge across the plasma membrane, critical for cellular activity.

Provides mechanical support and helps maintain cell shape; anchors membrane proteins.

Process by which a cell converts an external signal into a functional response.

Proteins that enable cells to adhere to each other and the extracellular matrix.

Specialized structures that connect cells, facilitating communication and structural integrity.

Tight junctions, gap junctions, and desmosomes, each serving different functions.

The pressure required to prevent the flow of water across a selectively permeable membrane.

Refers to the ability of a solution to affect cell volume through osmotic pressure.

A solution with equal solute concentration compared to the cell, resulting in no net movement of water.

A solution with a higher solute concentration than the cell, causing water to exit the cell and leading to shrinkage.

A solution with a lower solute concentration than the cell, causing water to enter the cell and leading to swelling.

Facilitate biochemical reactions at the membrane interface, enhancing reaction rates.

Involves receptor activation, relay proteins, and cellular responses to external signals.

Small membrane-bound sacs that transport materials within the cell and to the membrane surface.

Serve as second messengers in signal transduction pathways, influencing various cellular processes.

Actively move ions and molecules against their concentration gradient, utilizing ATP.

Continuous remodeling and movement of the plasma membrane, essential for cellular adaptation.

Distribution of lipids and proteins is uneven across the bilayer, influencing membrane properties and functions.

Specialized areas in the membrane that concentrate specific proteins and lipids, facilitating cellular processes.

Cholesterol-rich microdomains that organize signaling molecules, enhancing their interactions.

Enable cells to communicate and respond to environmental changes through signaling pathways.