Unlock hundreds more features
Save your Quiz to the Dashboard
View and Export Results
Use AI to Create Quizzes and Analyse Results

OR
Sign inSign in with Facebook
Sign inSign in with Google
Quizzes > Science > Biology

Ready to Ace Biology 1406 Exam 2? Take the Quiz Now!

Think you know membrane transport & cellular processes? Dive into the Biology 1406 Exam 2 quiz!

Difficulty: Moderate
2-5mins
Learning OutcomesCheat Sheet
Paper art illustration for Biology 1406 Exam 2 quiz on cellular processes on a golden yellow background

Ready to ace your "biology 1406 exam 2"? Dive into our free quiz for students mastering cell membrane dynamics and transport - from osmosis to exocytosis. Whether you're prepping for your biol 1406 final exam or craving a focused membrane fluidity test, this interactive cellular processes quiz will sharpen your cell biology skills. Challenge yourself with osmosis exocytosis quiz scenarios, reinforce key concepts, and boost your confidence in a fun, stress-free setting. Try a quick Cellular processes quiz or broaden your scope with a test in biology now - let's get started!

Which process describes the movement of water across a semipermeable membrane?
Osmosis
Diffusion
Facilitated diffusion
Active transport
Osmosis is the passive movement of water molecules through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration. It requires no energy input and is driven purely by differences in water potential. This process is critical for maintaining cellular turgor pressure and overall fluid balance. Reference
Which membrane component helps maintain fluidity by preventing fatty acid tails from packing tightly together?
Cholesterol
Phospholipid head groups
Glycoproteins
Carbohydrate chains
Cholesterol inserts between phospholipid fatty acid tails, disrupting van der Waals interactions and thus preventing tight packing. At low temperatures it increases fluidity, while at high temperatures it stabilizes the membrane. This bidirectional role makes cholesterol a key regulator of membrane consistency. Reference
What energy source does the Na+/K+ ATPase use to transport ions against their gradients?
ATP hydrolysis
GTP hydrolysis
Proton-motive force
Glucose oxidation
The Na+/K+ pump is a P-type ATPase that hydrolyzes ATP to ADP and phosphate, using the released energy to move three Na+ ions out and two K+ ions into the cell against their concentration gradients. This activity is essential for maintaining membrane potential and cell volume. The phosphorylated intermediate mechanism is characteristic of P-type ATPases. Reference
In passive transport, which direction do solutes move relative to their concentration gradient?
From high concentration to low concentration
From low concentration to high concentration
In equal amounts both ways
Only via vesicle formation
Passive transport relies on the inherent kinetic energy of molecules, so solutes move down their concentration gradient—from regions of higher concentration to regions of lower concentration—without energy input. This includes simple diffusion and facilitated diffusion. It is a key process for gas exchange and nutrient uptake. Reference
Which transport mechanism requires a specific carrier protein but no direct ATP consumption?
Facilitated diffusion
Active transport
Endocytosis
Osmosis
Facilitated diffusion employs transmembrane proteins (channels or carriers) to help polar or charged molecules cross the membrane without direct ATP usage, moving down their concentration gradients. The process is saturable and specific to the substrate. It differs from active transport, which requires energy input. Reference
Which process involves the engulfment of large particles or cells by a vesicle?
Phagocytosis
Pinocytosis
Exocytosis
Receptor-mediated transport
Phagocytosis is a form of endocytosis where the cell membrane extends pseudopodia to enclose large particles or microorganisms, forming a phagosome. This process is used by immune cells like macrophages to clear pathogens. It requires actin remodeling but not ATP for vesicle formation directly. Reference
What is the correct description of exocytosis?
Fusion of vesicles with the plasma membrane to release contents
Intake of extracellular fluid
Passive diffusion of small solutes
Movement of proteins into the nucleus
Exocytosis is the process by which intracellular vesicles fuse with the plasma membrane, releasing their cargo (e.g., hormones, neurotransmitters) into the extracellular space. It is essential for secretion and membrane recycling. SNARE proteins mediate the vesicle–membrane fusion. Reference
Which type of cell junction forms a seal that prevents leakage between epithelial cells?
Tight junction
Desmosome
Gap junction
Adherens junction
Tight junctions (zonula occludens) form a belt-like seal around epithelial cells, preventing the passage of materials between cells. They are composed of claudins and occludins that link neighboring membranes. This barrier function is critical in tissues like the intestine and kidney. Reference
A solution with lower solute concentration than the inside of a cell is termed:
Hypotonic
Hypertonic
Isotonic
Equitonic
In a hypotonic solution, extracellular solute concentration is lower than that inside the cell, causing water to move into the cell by osmosis. This can lead to cell swelling or even lysis. Hypertonic and isotonic describe higher and equal solute concentrations, respectively. Reference
Which region of a phospholipid is hydrophobic?
Fatty acid tails
Phosphate head
Glycerol backbone
Polar head group
The fatty acid tails of phospholipids are composed of long hydrocarbon chains that repel water, making them hydrophobic. The phosphate-containing head is polar and hydrophilic. Together they form the bilayer structure of cell membranes. Reference
Which process involves the nondirected uptake of extracellular fluid by small vesicles?
Pinocytosis
Phagocytosis
Exocytosis
Receptor-mediated endocytosis
Pinocytosis, or “cell drinking,” involves the invagination of the plasma membrane to form small vesicles that nonspecifically enclose extracellular fluid and solutes. It is constitutive in many cell types and differs from phagocytosis, which engulfs large particles. Reference
Which diffusion method is characterized by saturable transport kinetics and specificity for substrates?
Facilitated diffusion
Simple diffusion
Active transport
Osmosis
Facilitated diffusion uses carrier proteins or channels that can become saturated at high substrate concentrations and are specific for certain molecules. It differs from simple diffusion, which is nonspecific and non-saturable. No ATP is required, as movement is down a concentration gradient. Reference
Which protein family forms water channels in cell membranes to speed up water transport?
Aquaporins
Cadherins
Clathrins
Integrins
Aquaporins are integral membrane proteins that selectively conduct water molecules in and out of the cell without allowing ions or other solutes to pass. Their structure forms a narrow pore lined with hydrophilic residues. They are essential for kidney function and fluid homeostasis. Reference
What distinguishes receptor-mediated endocytosis from other endocytic pathways?
Selective uptake via ligand–receptor binding
Nonselective fluid uptake
Engulfment of large particles
Vesicle fusion with Golgi
Receptor-mediated endocytosis uses specific cell-surface receptors that bind ligands to concentrate cargo in coated pits, forming coated vesicles. This mechanism is highly selective and allows efficient uptake of molecules like LDL and transferrin. Clathrin typically coats the forming vesicles. Reference
Which fluid-mosaic model component can move laterally very quickly within the membrane?
Phospholipids
Integral proteins
Extracellular glycoproteins
Cholesterol
Phospholipids can diffuse laterally within the same leaflet at rates of up to 10^-7 cm^2/s, making membranes fluid. Integral proteins also move but more slowly and may be anchored. Flip-flop between leaflets is rare without flippases. Reference
Which cellular process secretes neurotransmitters at synaptic clefts?
Exocytosis
Endocytosis
Phagocytosis
Pinocytosis
Neurotransmitters are stored in synaptic vesicles that fuse with the presynaptic membrane in response to Ca2+ influx, releasing their contents into the synaptic cleft via exocytosis. This rapid secretion is essential for neuronal communication. Reference
How do unsaturated fatty acid tails affect membrane fluidity?
They increase fluidity by creating kinks
They decrease fluidity by packing tightly
They have no impact on fluidity
They cause membrane perforation
Unsaturated fatty acids contain one or more double bonds that introduce kinks in their tails, preventing tight packing and thereby increasing membrane fluidity. Cells adjust the ratio of saturated to unsaturated lipids in response to temperature changes. Reference
Which transport mechanism moves glucose into muscle cells via specific carrier proteins without ATP?
Facilitated diffusion
Primary active transport
Symport with Na+
Phagocytosis
GLUT transporters mediate facilitated diffusion of glucose into muscle and fat cells down its concentration gradient without using ATP directly. Primary active transport, such as the Na+/K+ pump, hydrolyzes ATP. Na+-glucose symport is used in intestinal uptake, not muscle. Reference
What drives secondary active transport across membranes?
Electrochemical gradient of one solute
Direct ATP hydrolysis
Endocytosis
Simple diffusion
Secondary active transport harnesses energy stored in the electrochemical gradient of an ion (commonly Na+ or H+) established by primary active transport to co-transport a second molecule against its gradient. No direct ATP hydrolysis occurs during the co-transport step. Reference
The pressure required to stop osmotic water flow across a membrane is called:
Osmotic pressure
Hydrostatic pressure
Turgor pressure
Vapor pressure
Osmotic pressure is the force needed to prevent water from moving across a semipermeable membrane by osmosis. It depends on solute concentration difference. It is distinct from hydrostatic pressure, which is due to fluid column height. Reference
Which cytoskeletal element links to adherens junctions and helps maintain tissue integrity?
Actin filaments
Microtubules
Intermediate filaments
Myosin filaments
Adherens junctions connect actin filaments of adjacent cells via cadherin proteins, forming a contractile actin belt under the membrane. This linkage provides mechanical strength and coordinates cell shape changes. Desmosomes use intermediate filaments instead. Reference
Who proposed the fluid mosaic model of membrane structure in 1972?
Singer and Nicolson
Davson and Danielli
Fluid and Mosaic
Watson and Crick
S.J. Singer and G.L. Nicolson introduced the fluid mosaic model in 1972, describing membranes as a dynamically moving lipid bilayer with embedded proteins. Earlier models like Davson-Danielli proposed a protein-lipid-protein sandwich. The fluid mosaic model better explains protein mobility and dynamics. Reference
Which organelle modifies, sorts, and packages proteins for secretion or delivery to other organelles?
Golgi apparatus
Endoplasmic reticulum
Lysosome
Mitochondrion
The Golgi apparatus receives newly synthesized proteins from the ER, further modifies them (e.g., glycosylation), sorts them, and packages them into vesicles for secretion or delivery. The rough ER synthesizes proteins, while lysosomes degrade waste. Reference
During receptor-mediated endocytosis, which protein coats the vesicle?
Clathrin
Caveolin
COPI
Cluadin
Clathrin assembles into a lattice on the cytosolic face of the plasma membrane, forming coated pits that invaginate to internalize receptor–ligand complexes. Caveolin-coated pits mediate caveolae formation, a different pathway. COPI coats vesicles in Golgi-to-ER transport. Reference
Which molecule is not a component of the plasma membrane?
DNA polymerase
Phospholipid
Cholesterol
Glycoprotein
DNA polymerase is a nuclear enzyme involved in DNA replication and is not part of the plasma membrane. Phospholipids, cholesterol, and glycoproteins are all key structural or functional membrane components. Reference
A 0.9% NaCl solution is generally considered isotonic to human red blood cells because its osmolarity matches intracellular fluid. True or False?
True
False
A 0.9% (w/v) NaCl solution has an osmolarity similar to that of human plasma (~300 mOsm/kg), making it isotonic to RBCs. Isotonic solutions prevent net water movement, maintaining cell shape. Hypotonic or hypertonic solutions would cause swelling or shrinking. Reference
Brownian motion is responsible for which of the following in cells?
Random movement of molecules
Directed vesicle trafficking
Active transport of ions
Polymerization of microtubules
Brownian motion refers to the random thermal movement of particles in a fluid, driving passive diffusion of small molecules in cells. It does not direct vesicle trafficking, which relies on motor proteins. Reference
Which characteristic best describes facilitated diffusion?
Saturable transport kinetics
Energy requirement from ATP
Cargo enclosed in vesicles
Involves hydrophobic gating
Facilitated diffusion demonstrates saturation because transporter proteins have a finite number of binding sites. Unlike active transport, it does not require ATP. Small hydrophobic molecules cross by simple diffusion, not facilitated. Reference
What is the main barrier to polar molecules crossing the lipid bilayer?
Hydrophobic core of lipid tails
Polar head groups
Membrane bound carbohydrates
Integral membrane proteins
The hydrophobic interior formed by fatty acid tails repels polar or charged molecules, making the lipid bilayer impermeable to them without transport proteins. Polar heads and proteins do not block passage of nonpolar molecules. Reference
Glycolipids are predominantly found on which side of the plasma membrane?
Extracellular leaflet
Cytosolic leaflet
Outer nuclear membrane
Mitochondrial membrane
Glycolipids have carbohydrate chains facing the extracellular environment, contributing to cell–cell recognition and protection. They are confined to the extracellular leaflet because glycosyltransferases face the lumen of Golgi. Reference
How does cholesterol affect membrane fluidity at high temperatures?
It decreases fluidity by restraining phospholipid movement
It increases fluidity by adding kinks
It has no effect at high temperatures
It forms micelles
At elevated temperatures, cholesterol intercalates between phospholipids and restricts their movement, reducing membrane fluidity and preventing the bilayer from becoming too permeable. This buffering effect maintains optimal membrane properties across temperature ranges. Reference
Which factor does not significantly affect the rate of simple diffusion across a membrane?
Membrane surface charge
Concentration gradient
Membrane thickness
Temperature
Simple diffusion is driven by concentration gradient, membrane thickness, and temperature. Membrane surface charge affects ion distribution and channel function but does not influence the passive diffusion rate of uncharged solutes. Reference
P-type ATPases are named for which characteristic feature in their mechanism?
They form a phosphorylated intermediate
They pump protons only
They rely on GTP binding
They do not hydrolyze ATP
P-type ATPases transiently phosphorylate a conserved aspartate residue during each transport cycle, which drives conformational changes necessary for ion translocation. This feature distinguishes them from V-type and F-type ATPases. Reference
What is the key difference between symporters and antiporters?
Symporters move two solutes in the same direction; antiporters move them in opposite directions
Symporters use ATP; antiporters do not
Symporters are channels; antiporters are carriers
Symporters only transport ions; antiporters only transport organics
Symporters cotransport two or more molecules in the same direction across the membrane, using the gradient of one to drive the other. Antiporters exchange substrates moving oppositely. Neither directly hydrolyzes ATP in the transport step. Reference
How do you calculate osmolarity of a solution made from a 1 M NaCl solute, assuming full dissociation?
2 Osm
1 Osm
0.5 Osm
3 Osm
NaCl dissociates fully into Na+ and Cl?, yielding two osmoles per mole of solute. Therefore, a 1 M NaCl solution has an osmolarity of 2 Osm/L. Partial dissociation or other salts yield different values. Reference
Water transport through aquaporins is best described as:
Facilitated diffusion
Active transport
Primary active transport
Diffusion through lipid bilayer
Aquaporins facilitate water movement down its osmotic gradient without using ATP, fitting the definition of facilitated diffusion. Although water can slowly diffuse through the lipid bilayer, aquaporins greatly increase permeability. Reference
Which caveolar component contributes to a distinct form of endocytosis in certain cell types?
Caveolin
Clathrin
Caveosome
COPII
Caveolins are integral membrane proteins that oligomerize and associate with cholesterol and sphingolipids to form caveolae, flask-shaped invaginations involved in endocytosis and signal transduction. This pathway is distinct from clathrin-mediated endocytosis. Reference
How does temperature generally affect membrane permeability to small solutes?
Permeability increases with temperature
Permeability decreases with temperature
Permeability is independent of temperature
Permeability is only pH-dependent
Rising temperature increases kinetic energy of molecules and phospholipid mobility, making membranes more fluid and thus more permeable to small solutes. At low temperatures, membranes become less fluid and less permeable. Reference
Which ion channel type primarily sets the resting membrane potential in neurons?
Potassium leak channels
Voltage-gated sodium channels
Ligand-gated chloride channels
Sodium–glucose symporters
Potassium leak channels allow K+ to move down its electrochemical gradient out of the cell, making the inside more negative and thus determining the resting membrane potential. Voltage-gated and ligand-gated channels open only upon specific stimuli. Reference
The Donnan equilibrium describes ion distribution when impermeant charged molecules are present. True or False?
True
False
The Donnan equilibrium occurs when a charged macromolecule (e.g., protein) cannot cross the membrane, causing unequal distribution of diffusible ions to balance charge and osmotic pressure. This can lead to cell swelling if unregulated. Reference
Which endocytic process is also referred to as “cell drinking”?
Pinocytosis
Phagocytosis
Receptor-mediated endocytosis
Autophagy
Pinocytosis nonspecifically uptake extracellular fluid and small molecules in vesicles and is colloquially called “cell drinking.” It contrasts with phagocytosis, which engulfs larger particles or cells. Reference
Low-density lipoprotein (LDL) uptake by cells occurs via which mechanism?
Receptor-mediated endocytosis
Pinocytosis
Phagocytosis
Exocytosis
Cells internalize LDL particles by binding them to specific LDL receptors, concentrating them in clathrin-coated pits that bud Vesicles for lysosomal degradation and cholesterol release. This selective process classifies as receptor-mediated endocytosis. Reference
A U-tube osmometer measures which property of a solute solution?
Osmotic pressure difference
Viscosity
Thermal conductivity
Electrical conductivity
A U-tube osmometer measures the osmotic pressure by observing the height difference of solvent columns separated by a semipermeable membrane, reflecting solute concentration. It does not gauge viscosity or conductivity. Reference
Which membrane movement occurs slowly and often requires flippase enzymes?
Phospholipid flip-flop between leaflets
Lateral diffusion
Rotation of lipids
Protein lateral diffusion
Flip-flop refers to the transbilayer movement of phospholipids from one leaflet to the other, which is energetically unfavorable and very slow without flippase enzymes. Lateral diffusion and rotation are rapid processes. Reference
Secondary active transport differs from primary active transport because it:
Uses existing ion gradients rather than ATP directly
Requires ATP hydrolysis at the transport protein
Transports only ions
Involves vesicle budding
Secondary active transport exploits the energy stored in ion gradients, usually established by primary active transport, to move substrates against their gradients without directly hydrolyzing ATP at the transporter. It can be symport or antiport. Reference
Which protein family mediates the final fusion of secretory vesicles with the plasma membrane during exocytosis?
SNARE proteins
Clathrin
Dynamin
COPI
SNARE proteins on vesicle (v-SNARE) and target membranes (t-SNARE) form a tight complex that pulls lipid bilayers together, driving membrane fusion and cargo release. This mechanism is essential in neurotransmitter release and hormone secretion. Reference
How does cholesterol orientation within the bilayer contribute to membrane curvature?
Its small polar head and rigid ring structure promote local bending
It prevents any curvature
It binds cytoskeletal elements directly
It increases bilayer thickness uniformly
Cholesterol’s planar sterol ring and small hydroxyl head group insert asymmetrically, inducing curvature in regions where it accumulates. This property is crucial in forming lipid rafts and vesicular buds. Reference
ABC transporters transport diverse substrates by which mechanism?
ATP binding and hydrolysis at cytosolic domains drive conformational changes
Proton gradients alone power substrate movement
They flip phospholipids only
Substrates move passively down gradients
ABC (ATP-Binding Cassette) transporters possess nucleotide-binding domains that bind and hydrolyze ATP, prompting conformational shifts that export or import substrates across membranes. These proteins cover drug efflux, lipid transport, and antigen presentation. Reference
How does the Gibbs–Donnan effect influence cell volume when impermeant anions are present inside the cell?
It causes water influx to balance ion distribution, increasing volume
It prevents any osmotic changes
It drives water efflux exclusively
It equalizes all ion concentrations
Impermeant intracellular anions attract counterions and exclude co-ions, creating an ionic imbalance that draws water into the cell by osmosis, potentially causing swelling unless regulated by ion pumps. This phenomenon is the Gibbs–Donnan effect. Reference
What specialized microdomains enriched in cholesterol and sphingolipids organize signaling molecules in the membrane?
Lipid rafts
Clathrin-coated pits
Caveolae
Tight junctions
Lipid rafts are dynamic assemblies of cholesterol, sphingolipids, and proteins that compartmentalize cellular processes by concentrating receptors and signaling proteins. They differ from caveolae by lacking caveolin. Reference
Which Rab protein is primarily involved in regulating recycling endosome trafficking back to the plasma membrane?
Rab11
Rab5
Rab7
Rab27
Rab11 is a small GTPase that controls protein recycling from endosomes to the plasma membrane, ensuring proper receptor and transporter delivery. Rab5 and Rab7 regulate early and late endosome dynamics, respectively. Reference
0
{"name":"Which process describes the movement of water across a semipermeable membrane?", "url":"https://www.quiz-maker.com/QPREVIEW","txt":"Which process describes the movement of water across a semipermeable membrane?, Which membrane component helps maintain fluidity by preventing fatty acid tails from packing tightly together?, What energy source does the Na+\/K+ ATPase use to transport ions against their gradients?","img":"https://www.quiz-maker.com/3012/images/ogquiz.png"}

Study Outcomes

  1. Understand facilitated diffusion and active transport mechanisms -

    Describe how carrier proteins and energy expenditure enable selective movement of molecules across the cell membrane.

  2. Analyze osmotic gradients and predict water movement -

    Interpret solute concentration differences to determine the direction and rate of osmosis in various cellular environments.

  3. Evaluate factors influencing membrane fluidity -

    Assess how temperature, lipid composition, and cholesterol content alter the viscosity and functionality of biological membranes.

  4. Explain the stepwise processes of endocytosis and exocytosis -

    Outline the molecular events by which cells internalize nutrients and secrete macromolecules via vesicle formation and fusion.

  5. Apply instant quiz feedback to improve exam readiness -

    Use your scored results to pinpoint knowledge gaps and reinforce key cellular process concepts for the Biology 1406 Exam 2.

Cheat Sheet

  1. Osmosis and Tonicity -

    Osmosis is the passive movement of water from a region of low solute concentration to high solute concentration through a semipermeable membrane, crucial for homeostasis (learn the "Osmosis Only Moves Solvent" mnemonic). Review isotonic, hypertonic, and hypotonic solutions to predict cell volume changes - vital for biology 1406 exam 2 questions on water balance. Practice drawing water potential gradients (Ψ = Ψs + Ψp) to master real-world scenarios.

  2. Facilitated Diffusion vs. Active Transport -

    Facilitated diffusion uses channel or carrier proteins to move molecules down their concentration gradient without ATP, whereas active transport uses ATP to move solutes against gradients. Remember GLUT transporters for facilitated diffusion and the sodium-potassium pump for primary active transport (3 Na+ out, 2 K+ in per ATP). This contrast forms a common biol 1406 final exam question on membrane transport mechanisms.

  3. Membrane Fluidity and Cholesterol -

    Phospholipid bilayer fluidity depends on temperature, fatty acid saturation, and cholesterol content; cholesterol acts as a "fluidity buffer" by preventing tight packing at low temps and restraining fluidity at high temps. Use the phrase "Chill Cholesterol Checks Fluidity" to recall its dual role. Consult university biochemistry resources for phase-transition graphs illustrating the liquid-ordered versus liquid-disordered states.

  4. Primary Active Transport: Na+/K+-ATPase -

    The Na+/K+-ATPase is a classic example of primary active transport, hydrolyzing one ATP to export three Na+ ions and import two K+ ions, establishing electrochemical gradients essential for nerve impulses. Understand the cycle: pump phosphorylation → conformational change → ion release/reload → dephosphorylation. Practice drawing the E1/E2 states to solidify this key concept for your membrane fluidity test and cellular processes quiz prep.

  5. Exocytosis and Vesicle Fusion -

    Exocytosis delivers large molecules (e.g., neurotransmitters, hormones) to the extracellular space via SNARE-mediated vesicle fusion with the plasma membrane. Recall the steps: vesicle budding, transport along cytoskeleton, SNAP-25/syntaxin docking, and Ca2+-triggered fusion. Flashcard the sequence "Bud, Travel, Dock, Fuse" to ace osmosis exocytosis quiz questions.

Make a Quiz (FREE) Copy & Edit This Quiz Create a Quiz with AI

Biology Quizzes

Powered by: Quiz Maker