Membrane Proteins Structure and Function Quiz

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What is the main function of membrane proteins in a cell?

Provide mechanical linkage for other proteins on either side of the membranes (correct)

Promote cell division by interacting with the nucleus

Store excess nutrients and ions for future use

Maintain the cell's shape and structure

Which type of membrane proteins are permanently bound to the lipid bilayer?

Carrier Proteins

Channel Proteins

Peripheral Proteins

Integral Proteins (correct)

What is the role of transport proteins in the cell membrane?

Act as energy producers for the cell

Facilitate movement of ions and small molecules across the membrane (correct)

Convert sunlight into cellular energy

Help in DNA replication

Which proteins sense a ligand on one side of the membrane and transmit a signal to the other side?

Membrane receptor proteins Signup and view all the answers

How do membrane receptor proteins serve as a connection between the cell's internal and external environments?

By acting as a signaling link between internal and external environments Signup and view all the answers

What is the ratio of the intracellular compartment to the total body fluids?

2/3 Signup and view all the answers

Which type of cell is around 100 µm in size?

Fat cell Signup and view all the answers

What is the main function of the cell membrane?

Regulate the exchange of nutrients, ions, and hormones with its environment Signup and view all the answers

Which fluid compartments are further subdivided into interstitial fluid and plasma?

Extracellular fluid Signup and view all the answers

What does the Darrow-Yannet Diagram explain?

Changes in the body fluid compartments with excessive salt intake, sweating, dehydration, etc. Signup and view all the answers

Which type of cell is the longest based on the provided information?

Smooth muscle cell Signup and view all the answers

What is the primary driving force for water movement in osmosis?

High solute concentration Signup and view all the answers

How does Aquaporins (AQPs) affect water permeability in cells?

Increase water permeability Signup and view all the answers

What is the role of Anti-diuretic hormone (ADH) in the kidneys regarding water reabsorption?

Increase water reabsorption Signup and view all the answers

How is osmolarity defined in a solution?

Concentration of solute particles per liter of solution Signup and view all the answers

In a 1mM NaCl solution, what is the osmolarity?

2 mOsm/L NaCl Signup and view all the answers

What does osmotic pressure represent in osmosis?

Mechanical pressure to produce water flow equal to the osmotic flow Signup and view all the answers

What does the Permeability (P) equation describe?

The relationship between the diffusion coefficient and the partition coefficient Signup and view all the answers

How does the concentration gradient affect the rate of diffusion?

Higher concentration gradient leads to faster diffusion Signup and view all the answers

What role do carrier proteins play in facilitated diffusion?

They facilitate solute movement by binding molecules on one side and releasing on the other side Signup and view all the answers

How does membrane thickness impact the rate of diffusion?

Thicker membrane leads to slower diffusion Signup and view all the answers

What happens if a substance is impermeable to a membrane?

No diffusion occurs Signup and view all the answers

How does increased membrane surface area affect diffusion?

Enhances diffusion rate Signup and view all the answers

What is the main function of ion channels in the cell membrane?

Generate electrical currents Signup and view all the answers

Which type of ion channel opens when physical forces cause the channel gates to open?

Mechanically-gated channels Signup and view all the answers

What initiates the opening of voltage-gated ion channels?

Change in electrical potential Signup and view all the answers

Which type of transporter facilitates the movement of two or more molecules across the plasma membrane in the same direction?

Symporters Signup and view all the answers

What is the function of antiporters (exchangers) in membrane transport?

Move ions and molecules in opposite directions Signup and view all the answers

Which membrane transport process requires no carrier protein or channel?

Simple Diffusion Signup and view all the answers

What factors affect the rate of diffusion through a cell membrane according to Fick’s Law?

Membrane surface area and lipid composition Signup and view all the answers

What does the Stokes-Einstein Equation describe in relation to molecular diffusion?

Inverse relationship between molecular radius and diffusion coefficient Signup and view all the answers

How do chemically-gated ion channels generate electrical signals?

From binding specific molecules like neurotransmitters or hormones Signup and view all the answers

Which type of transporter requires energy to move molecules across the membrane?

Symporters Signup and view all the answers

What is the primary driving force for the movement of 3 Na+ ions out of the cell and 2 K+ ions into the cell by the Na-K ATPase pump?

Hydrolysis of one ATP molecule Signup and view all the answers

Which type of ATPase pump is responsible for maintaining ionic gradients by moving ions against their gradients?

P-type ATPase Signup and view all the answers

What is the most abundant pump in eukaryotic cells that is classified as a P-type ATPase?

Na-K Pump Signup and view all the answers

Which drugs are known to block the activity of the Na-K Pump?

Digitalis and ouabain Signup and view all the answers

What is the primary function of V-ATPases in cellular processes?

Coupling ATP hydrolysis to pump protons Signup and view all the answers

Which of the following pumps calcium from the cytoplasm into the sarcoplasmic reticulum in muscle cells?

SERCA Pump Signup and view all the answers

What is the main role of integral membrane proteins in the cell membrane?

Mediate the selective movement of ions across the membrane Signup and view all the answers

Which type of membrane proteins are temporarily associated with the lipid bilayer or with integral membrane proteins?

Peripheral Proteins Signup and view all the answers

What is the primary function of carrier proteins in the cell membrane?

Facilitate the selective movement of ions and small molecules across the membrane Signup and view all the answers

How do channel proteins differ from carrier proteins in membrane transport?

Channel proteins facilitate the movement of molecules through a pore Signup and view all the answers

In what way do membrane receptor proteins act as intermediaries between a cell's internal and external environments?

By sensing ligands and transmitting signals across the membrane Signup and view all the answers

What proportion of the total body fluid compartments does the intracellular compartment account for?

2/3 Signup and view all the answers

Which cell type listed is among the smallest based on the provided information?

Red blood cell Signup and view all the answers

What is the primary function of the cell (plasma) membrane?

Regulate exchange of nutrients, ions, and hormones Signup and view all the answers

What is the primary role of the Darrow-Yannet Diagram in explaining body fluid compartments?

Explain osmolarity changes with salt intake Signup and view all the answers

Which of the following is NOT a function of the cell (plasma) membrane?

Synthesize hormones Signup and view all the answers

How do interstitial fluid and plasma relate to cells?

They are subcategories of extracellular fluid that interact with cells Signup and view all the answers

What is the main function of ATP-binding cassette (ABC) transporters?

Consume ATP while transporting molecules across membranes Signup and view all the answers

Where is the SGLT transporter primarily active in transporting sodium and glucose?

Intestine or kidney Signup and view all the answers

What is the consequence of the multidrug resistance (MDR) pump being highly expressed in bacteria and cancer cells?

Increases the excretion of drugs resulting in a loss of potency Signup and view all the answers

What role does Na-K ATPase play in secondary active transport involving the SGLT transporter?

Creates a high-affinity site for glucose binding Signup and view all the answers

How does glucose binding change carrier conformation in secondary active transport by the SGLT protein?

It ensures binding sites face the intracellular fluid Signup and view all the answers

What is the primary source of energy used by symporters like the SGLT protein for secondary active transport?

Na-K ATPase gradient Signup and view all the answers