Harper's Biochemistry Chapter 40 - Membranes (Structure & Function)

Which mechanism primarily contributes to the self-assembly of lipid bilayers in an aqueous environment?

Which factor primarily determines the transition temperature (Tm) of a membrane?

What is the primary function of flippases in cell membranes?

Which statement accurately describes the function of the multidrug-resistance-1 (MDR-1) protein?

In the context of transmembrane signaling, what role do scaffolding proteins play?

What is the primary mechanism by which bacteria adapt to changes in temperature to maintain membrane fluidity?

During signal transduction, what is the immediate consequence of a ligand binding to a receptor tyrosine kinase (RTK)?

Which characteristic distinguishes active transport from facilitated diffusion?

What role does cholesterol play in modulating membrane fluidity?

Which mechanism explains how cells internalize large particles, such as bacteria or cellular debris?

How do proteins associate with membranes via lipid anchors?

What is the role of dynamin in clathrin-mediated endocytosis?

Which of the following is NOT a function of membrane proteins?

What is the role of aquaporins in cell membranes?

Which of the following best describes the effect of an increase in the proportion of unsaturated fatty acids in the phospholipids of a plasma membrane?

What is the primary function of tight junctions in epithelial cell sheets?

Which of the following is a characteristic feature of lipid rafts?

During the transmission of a nerve impulse, what is the role of the Na+/K+-ATPase?

Which mechanism is used by insulin to increase glucose uptake in adipocytes and muscle cells?

How does ouabain inhibit the Na+/K+-ATPase?

What role does the mannose-6-phosphate (M6P) moiety play in the trafficking of lysosomal hydrolases?

What is the structural basis for the selectivity of potassium (K+) channels?

Which of the following is an example of a disease caused by a mutation affecting the membrane protein that is a chloride transporter?

In the context of membrane transport, what does the term 'ping-pong' mechanism refer to?

What is the significance of lipid asymmetry in cell membranes?

What is the role of spectrin in the erythrocyte membrane?

What distinguishes exosomes from microvesicles?

Which of the following is INCORRECT regarding gap junctions?

The process in which cells take up solutes in a non-selective manner proportional to the solutes's concentration in the surrounding fluid is:

What ensures selectivity when cells perform absorptive pinocytosis?

The rapid lateral movements of membrane components and proteins is directly dependent on:

Which of the following would be LEAST likely to freely traverse the cell membrane?

How do local changes in Ca2+ concentration trigger exocytosis?

Which of the following determines a particular protein's placement in the plasma membrane?

When describing the types of transport systems, what is a uniport system?

How does the asymmetry of membrane phospholipids primarily affect cellular function?

What accounts for the selective permeability of the plasma membrane in eukaryotic cells?

How does protein lipidation influence protein-membrane interactions and cellular processes?

What is the consequence of increased cholesterol levels above the transition temperature (Tm) in mammalian plasma membranes?

What is the main structural difference between lipid rafts and caveolae?

How do mechanically gated ion channels transduce mechanical stimuli into electrical signals?

What is the primary function of assembly particles in absorptive pinocytosis?

How do bacterial cells typically respond to a sudden decrease in temperature to maintain their membrane fluidity?

What role does dynamin play in the process of clathrin-mediated endocytosis?

During oxidative phosphorylation, how does the F-type ATPase (ATP synthase) function in mitochondria?

What is a key distinction between uniport and symport transport systems?

How does an increase in membrane fluidity affect the activity of an integral membrane protein where the active site is only in its hydrophilic regions?

What is the structural basis for how gap junctions allow direct flow of molecules from one cell to another?

Why are the hydrophobic regions of amphipathic phospholipids shielded from water in a micelle?

How does the Na+/K+ ATPase contribute to the negative resting membrane potential observed in neurons?

What is the functional consequence of membrane proteins misfolding that arise from genetic mutations?

What is correct regarding the mechanism used in oral dehydration therapy?

Compared to simple diffusion, why is facilitated diffusion faster?

When the membrane lipids undergo a transition from ordered to disordered, how does this affect membranes?

What is the function of the enzyme translocases (flippases) in a cell?

Describe Lipid Bilayer sheets:

Why is it essential that cells maintain electrochemical gradients?

In facilitated diffusion, what directly determines the rate at which a solute enters the cell?

A mutation causes an abnormality in the oligosaccharide chains of membrane glycoproteins and glycolipids. What disease is most likely to occur?

A researcher is studying a membrane transport protein and mutates a single amino acid within the protein's transmembrane domain. Surprisingly, they observe that the rate of transport for the protein's substrate is reduced, but binding affinity remains unchanged. What is can be inferred?

A researcher discovers a novel protein that interacts with certain membrane lipids. How can such a discovery advance our understanding of membrane organization and function?

Which strategy would be the MOST effective in determining whether a newly discovered protein localizes to lipid rafts?

Ouabain and digitalis affect the Na+/K+ -ATPase in what way and why?

What is the fate of the contents transported via endocytosis?

Why are the rates of transfer faster for ion channels than transporters?

Ions are water soluble, what features allow them to move through hydrophobic interior of membranes?

What is the role the protein caveolin-1?

Which of the following diseases has shown success with gene therapy?

What is true of most integral proteins?

In the membrane's fluid mosaic model, what can be used to liken it to icebergs?

If a research is studying the fluidity of a membrane, which fatty acid chain would create a larger T (transition temperature)?

Which characteristic of the erythrocyte membrane is most directly related to its biconcave shape and flexibility?

In what way do the properties of tight junctions contribute to this phenomenon?

How do cells ensure that the necessary GLUT4 transporters are available at the cell surface post-insulin stimulation?

What role do the sugar moieties of glycoproteins and glycolipids play in cellular recognition?

How would valinomycin mediate this selectivity?

How does the specific arrangement of carbonyl oxygen atoms within the K+ channel contribute to its function?

How does the polarity of amino acids affect the proteins found in the plasma membrane?

If the expression of phospholipid translocases were altered, what would likely occur?

In what way do lipid anchors contribute to the function of particular membrane proteins?

What is the significance of maintaining disparate ionic compositions inside and outside a cell?

Why are liposomes useful for biochemical studies of membrane function?

How does clathrin facilitate the formation of specialized coated pits that target molecules for endocytosis?

How do the actions of the various types of ATP-dependent transporters differ?

What property makes integral membrane proteins difficult to isolate and study?

What role might cholesterol play?

Why do membranes usually contain certain unsaturated fatty acids?

Facilitated diffusion transports...

What could be a factor?

When would a Na+-glucose...

How is a nerve impulse...

In cystic fibrosis...

What is the role of connexons and gap junctions?

How do microvesicles contribute to cellular physiology?

Which mechanism is important for endocytosis/vesicle pinching?

If there is a tumor...

Which structure would be best for drug release in the blood?

Ions are moved rapidly...

How do membrane proteins regulate their structure?

What force can induce a conformational change?

Insulin resistance is caused ...?

The gate part of the channel...

For a high selectivity...

What is the first...

Cholera can be treated...

Endocytosis happens in...

Exocytosis occurs after...

The sugar component transmits?

What do cell junctions allow?

Extracellular vesicles have a lot of?

Mutations can alter:

How does the asymmetry of phospholipids in cell membranes contribute to cellular function, beyond simply maintaining structural integrity?

What is the functional consequence of cholesterol's buffering effect on membrane fluidity at different temperatures?

How would disrupting the function of lipid flippases most directly affect cellular processes?

Which mechanism primarily contributes to the rapid and selective transport of potassium (K+) ions through their respective channels, and why is this crucial for cell function?

What is the molecular basis for how bacterial cells modify their membrane lipid composition to maintain membrane fluidity when exposed to low temperatures?

How do caveolae and lipid rafts coordinate to influence particular cellular functions differently?

Which statement explains why certain drugs can readily pass through cell membranes?

What role do assembly particle proteins play in absorptive pinocytosis?

How does the Na+/K+-ATPase contribute to maintaining cellular homeostasis?

What determines the selectivity of transmembrane channels for specific ions?

Plasma membranes are static structures with fixed compositions of lipids and proteins.

The main function of intracellular membranes is to prevent the formation of distinct compartments within the cell.

Selective molecular permeability of plasma membranes is achieved through the action of specific transporters and ion channels.

Intracellular fluid (ICF) represents about one-third of the total body water in humans.

The extracellular fluid (ECF) is primarily static and does not actively deliver nutrients or remove waste from cells.

Extracellular fluid is characterized by a high concentration of K+ and Mg2+.

Membranes consist of a symmetric lipid bilayer with identical inner and outer surfaces.

Myelin has an unusually high lipid content compared to other membranes.

Phosphoglycerides consist of a sphingosine backbone with two fatty acids attached via ester linkages and an alcohol.

Cholesterol is a sterol commonly found in plant cell membranes.

Membrane lipids are considered amphipathic due to the presence of both hydrophobic and hydrophilic regions.

Saturated fatty acids in membrane lipids form kinked tails, increasing membrane fluidity.

Detergents are amphipathic molecules that are used to solubilize and purify membrane proteins.

The lipid bilayer is permeable to most water-soluble molecules.

Membrane phospholipids act as a solvent for membrane proteins, creating an environment in which the latter can function.

Protein lipidation involves proteins that are anchored to one leaflet of the bilayer by covalent linkages to carbohydrates.

In the fluid mosaic model, only the lipid components of the membrane are able to move laterally.

Translocases (flippases) transfer certain phospholipids, such as phosphatidylcholine, from the outer to the inner leaflet of the membrane.

Peripheral proteins require detergents for their release from the membrane.

Liposomes loaded with DNA are highly sensitive to attack by nucleases.

Match the following membrane lipids with their key structural feature:

Match the following membrane transport mechanisms with their primary characteristic:

Match the following components of a Na+ channel with their function:

Match the membrane protein type with its key characteristic:

Match the following properties with either Lipid Rafts or Caveolae:

Match the type of ATP-driven active transporter with its characteristics:

Match the step of glucose transport across the intestinal cell with its feature:

Match the property to the correct form of vesicular transport:

Match the diseases related to membrane protein malfunction with their malfunction:

Match the following regarding nerve cells: