Transport Across Cell Membranes Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary energy source for primary active transport?

The direct breakdown of ATP.

Describe the role of the Sodium-Potassium pump in cellular function.

It exchanges three Na+ ions out of the cell for two K+ ions into the cell, maintaining the electrochemical gradient.

What distinguishes secondary active transport from primary active transport?

Secondary active transport uses the sodium concentration gradient created by the Na+-K+ ATPase pump for energy instead of direct ATP breakdown.

Give an example of a primary active transport process and explain how it functions.

The Calcium ATPase pump moves Ca++ ions out of the cell against their concentration gradient using ATP energy. Signup and view all the answers

What is the role of carrier proteins in transport mechanisms?

Carrier proteins facilitate the movement of specific molecules across the cell membrane by changing shape. Signup and view all the answers

Explain the function of symport carriers in secondary active transport.

Symport carriers transport two molecules in the same direction across the membrane, using the gradient of one molecule to drive the transport of another. Signup and view all the answers

Identify an example of an antiport carrier and describe its mechanism.

The Sodium-Hydrogen exchanger moves Na+ ions into the cell while transporting H+ ions out, maintaining pH balance. Signup and view all the answers

How does the conformational change in a carrier protein affect transport?

The conformational change allows the carrier to bind and release molecules on either side of the cell membrane, facilitating transport. Signup and view all the answers

What is the significance of the sodium concentration gradient in secondary active transport?

It provides the driving force necessary for the co-transport of other molecules against their concentration gradients. Signup and view all the answers

What is the main function of the sodium-potassium pump in cells?

The sodium-potassium pump maintains cell volume and contributes to resting membrane potential by pumping 3 sodium ions out and 2 potassium ions into the cell using one ATP. Signup and view all the answers

How does the calcium ATPase pump contribute to muscle relaxation?

The calcium ATPase pump keeps intracellular calcium levels low, which is essential for the relaxation of skeletal and cardiac muscle. Signup and view all the answers

Describe the energy source used in secondary active transport.

Secondary active transport utilizes the electrochemical gradients established by primary active transport as its energy source to move substances against their gradients. Signup and view all the answers

What is a symport carrier and provide an example?

A symport carrier is a type of cotransporter that moves two substances in the same direction; an example is the sodium-glucose cotransporter. Signup and view all the answers

What role does ATP hydrolysis play in the function of primary active transport mechanisms?

ATP hydrolysis provides the energy necessary for primary active transport mechanisms to move ions against their concentration gradients. Signup and view all the answers

In the context of the resting membrane potential, what does it mean that the inside of the cell is negative relative to the outside?

It means there is a higher concentration of positive ions outside the cell, leading to a net negative charge inside due to the activity of the sodium-potassium pump. Signup and view all the answers

What is primary active transport and how does it differ from passive transport?

Primary active transport moves molecules against their concentration gradient, requiring energy, while passive transport allows molecules to move down their gradient without energy input. Signup and view all the answers

Explain how the sodium-potassium pump facilitates secondary active transport.

The sodium-potassium pump creates a high concentration of sodium outside the cell, enabling the movement of sodium back into the cell to drive the transport of other substances like glucose against their gradient. Signup and view all the answers

Describe the function of the sodium-potassium pump in cellular transport.

The sodium-potassium pump actively transports sodium ions out of the cell and potassium ions into the cell, maintaining the cell's electrochemical gradient. Signup and view all the answers

What is the role of the calcium ATPase pump in muscle contraction?

The calcium ATPase pump removes calcium ions from the cytoplasm to the sarcoplasmic reticulum, allowing muscles to relax after contraction. Signup and view all the answers

Explain secondary active transport and how it utilizes primary active transport.

Secondary active transport uses the energy created by primary active transport to move other substances against their concentration gradient. Signup and view all the answers

What are carrier proteins and what is their function in facilitated diffusion?

Carrier proteins facilitate the transport of large water-soluble molecules across the cell membrane by binding to the substance and changing shape. Signup and view all the answers

How do gated ion channels contribute to the selective permeability of the cell membrane?

Gated ion channels open or close in response to specific signals, allowing selective passage of ions based on cellular needs. Signup and view all the answers

What is the significance of the transport maximum in facilitated diffusion?

The transport maximum represents the limit of how much substance can be transported per unit time based on the number and activity of carrier proteins. Signup and view all the answers

In what way does water solubility influence the mechanism of diffusion for different substances?

Water-soluble molecules require facilitated diffusion via carriers, while lipid-soluble molecules can easily pass through the membrane via simple diffusion. Signup and view all the answers

What role do ligands play in gated ion channels?

Ligands bind to ligand-gated ion channels, causing them to open or close and regulate ion flow across the membrane. Signup and view all the answers

Flashcards

Primary Active Transport

Movement of molecules across a membrane using energy from ATP hydrolysis, moving molecules against their concentration gradient.

Na+-K+ Pump

A primary active transport protein that moves 3 sodium ions out of and 2 potassium ions into a cell, using one ATP molecule.

Secondary Active Transport

Movement of molecules across a membrane using energy from an existing ion gradient, rather than directly from ATP.

Symport Carrier

A type of carrier protein in secondary active transport that moves two or more substances in the same direction across the membrane.