Cell Biology: Organelles and Functions

<p>Mimicry of glycoproteins (D)</p> Signup and view all the answers

<p>Their charge prevents easy movement across the lipid core. (C)</p> Signup and view all the answers

<p>HIV rapidly evolves through mutation. (A)</p> Signup and view all the answers

<p>It is a passive movement of substances down their concentration gradient. (D)</p> Signup and view all the answers

<p>They need assistance from specific transport proteins. (A)</p> Signup and view all the answers

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

<p>It accelerates the rate of diffusion. (D)</p> Signup and view all the answers

<p>They recognize and destroy the virus. (B)</p> Signup and view all the answers

<p>It describes the concentration of solute in a solution. (D)</p> Signup and view all the answers

<p>Small ions and large polar molecules (C)</p> Signup and view all the answers

<p>To selectively allow substances while protecting the cell (D)</p> Signup and view all the answers

<p>When substances move from high to low concentration. (D)</p> Signup and view all the answers

<p>Decreased effectiveness of antibodies. (A)</p> Signup and view all the answers

<p>It decreases the rate of diffusion. (C)</p> Signup and view all the answers

<p>Color of the solution (A)</p> Signup and view all the answers

<p>Higher temperatures increase molecular energy and movement. (D)</p> Signup and view all the answers

<p>They form channels or carriers to assist material passage across the membrane. (A)</p> Signup and view all the answers

<p>Osmosis only refers to the movement of water molecules. (C)</p> Signup and view all the answers

<p>Large polar substances (A)</p> Signup and view all the answers

<p>From high to low concentration (A)</p> Signup and view all the answers

<p>The rate of diffusion decreases. (C)</p> Signup and view all the answers

<p>They bind with specific substances to transmit messages into the cell. (B)</p> Signup and view all the answers

<p>The dynamic and flexible nature of the membrane structure. (B)</p> Signup and view all the answers

<p>To cause platelet adhesion and vessel constriction (D)</p> Signup and view all the answers

<p>They mimic specific substances to gain entry into the cell. (C)</p> Signup and view all the answers

<p>Tight junction (A)</p> Signup and view all the answers

<p>They enable cells to recognize one another. (A)</p> Signup and view all the answers

<p>Lipids and proteins can move laterally within the membrane. (C)</p> Signup and view all the answers

<p>To connect cytoplasm of adjacent cells for communication (C)</p> Signup and view all the answers

<p>Desmosome (A)</p> Signup and view all the answers

<p>Energy production, synthesis of substances, and waste disposal. (A)</p> Signup and view all the answers

<p>The ability of components to flow while maintaining the membrane's structure. (A)</p> Signup and view all the answers

<p>To allow for the transport of nutrients and signaling molecules (C)</p> Signup and view all the answers

<p>They form seals to prevent leaks between cells. (C)</p> Signup and view all the answers

<p>They represent a diverse mix of proteins, lipids, carbohydrates, and cholesterol. (D)</p> Signup and view all the answers

<p>Epithelial tissue (A)</p> Signup and view all the answers

<p>Gap junction (B)</p> Signup and view all the answers

<p>Water moves from high to low concentration of free water molecules. (D)</p> Signup and view all the answers

<p>The cell gains water and may swell. (B)</p> Signup and view all the answers

<p>Water molecules. (C)</p> Signup and view all the answers

<p>The total amount of solutes dissolved in a specific amount of solution. (D)</p> Signup and view all the answers

<p>Molecules will spread evenly in a medium if they can. (A)</p> Signup and view all the answers

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

<p>Water diffusion stops. (B)</p> Signup and view all the answers

<p>Concentration of solute. (C)</p> Signup and view all the answers

Channels between plant cell walls that connect their cytoplasm, allowing transport of molecules.

Structures that allow cells to communicate and interact by direct contact.

Watertight seals between animal cells, preventing leakage.

Spot welds between animal cells, holding tissues together to withstand stretching.

Channels between animal cells allowing transport of small molecules and ions.

Platelets sticking to damaged blood vessel walls, triggered by tissue factor.

Narrowing of a blood vessel, triggered by smooth muscle cells.

Platelets producing components necessary for blood clotting, initiated by the platelets.

Specific molecules on the surface of host cells that viruses exploit to infect specific organs.

HIV targets specific white blood cells (T-helper cells and monocytes) and some cells of the central nervous system.

Hepatitis virus specifically infects liver cells.

Viruses mimic the molecules on the surface of host cells to gain entry.

Specific sites on a virus's surface interact with the immune system, causing the production of antibodies.

Antibodies are produced by the immune system to destroy or inhibit the activity of viruses.

HIV's genes encoding surface recognition sites change rapidly, making vaccine development challenging.

Changes in the viral surface markers decrease the effectiveness of the immune system in fighting the virus.

Molecules on the cell surface that allow cells to recognize each other, crucial for tissue and organ formation and immune response.

Binding sites on the cell surface that interact with specific substances, triggering changes within the cell.

Receptors activate internal processes within the cell, such as metabolic pathways, energy production, waste removal, and signal transduction.

Viruses exploit specific receptors on the cell surface to gain entry into the cell.

Describes the plasma membrane as a dynamic structure with components (phospholipids, cholesterol, proteins, carbohydrates) that can move freely.

The ability of membrane components to move laterally, crucial for membrane function, enzyme activity, and transport.

Phospholipid molecules can diffuse rapidly and laterally within the membrane.

Embedded proteins can also diffuse and move within the membrane, contributing to membrane fluidity.

The movement of water molecules across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.

A substance that dissolves in a solvent to form a solution.

A substance that dissolves a solute to form a solution.

A membrane that allows certain substances to pass through while blocking others.

The relative concentration of solutes in two solutions, like the inside and outside of a cell.

A solution with a lower solute concentration than the inside of a cell.

A solution with a higher solute concentration than the inside of a cell.

A solution with the same solute concentration as the inside of a cell.

A passive process where a substance moves from a high concentration area to a low concentration area until it becomes evenly distributed.

The difference in concentration of a substance between two areas.

Diffusion is driven by the difference in concentration between two areas, causing the substance to move from high to low concentration.

The rate of diffusion is affected by the extent of the concentration gradient, the size of the molecules, and the temperature.

A greater difference in concentration leads to faster diffusion.

Smaller molecules diffuse faster.

Higher temperatures result in faster diffusion.

Diffusion can occur across the plasma membrane, allowing for the transport of small molecules like oxygen and carbon dioxide.

The rate of diffusion depends on how close the substance is to equilibrium, the molecular mass, the temperature, and the density of the solvent. Diffusion slows down as the substance gets closer to equilibrium, larger molecules diffuse slower, higher temperatures increase diffusion speed, and denser solvents slow down diffusion.

Facilitated diffusion is a type of passive transport where molecules move across a membrane with the help of transport proteins, going from a high concentration to a low concentration without using cell energy.

These proteins act as channels or carriers, assisting molecules in crossing the plasma membrane during facilitated diffusion.

Osmosis is the movement of water molecules across a semipermeable membrane from an area of high water concentration to an area of low water concentration.

Water moves across a semipermeable membrane to balance the concentration of solutes on both sides, aiming for equal solute concentrations.

Osmosis is influenced by the concentration gradient of water, the permeability of the membrane, and the pressure difference across the membrane.

Equilibrium is reached when the concentration of the substance or water is the same on both sides of the membrane, resulting in no net movement.