Compendium 5

Exocytosis allows neurotransmitter release by secretory vesicles fusing with the plasma membrane.

Phagocytosis involves engulfing large particles, while pinocytosis is the engulfing of small particles and fluids.

Osmosis is driven by the concentration of solutes, as water moves from low solute concentration to high solute concentration.

<p>In a hypertonic solution, red blood cells lose water, leading to crenation and deformation.</p> Signup and view all the answers

<p>Facilitated diffusion is the process where solutes bind to specific transporters and move down a concentration gradient without energy, while active transport moves solutes against a gradient and requires energy, usually from ATP.</p> Signup and view all the answers

<p>Ion channels are specific proteins that allow selective ions to pass through the membrane, facilitating their movement in accordance with electrochemical gradients.</p> Signup and view all the answers

<p>Aquaporins are transmembrane proteins that function as channels, allowing water to pass through the lipid bilayer efficiently.</p> Signup and view all the answers

<p>Gated protein channels only open in response to specific signals, allowing ions to pass when active, thus regulating ion flow based on cellular needs.</p> Signup and view all the answers

<p>Osmotic pressure is proportional to the concentration of solute particles that cannot cross the membrane.</p> Signup and view all the answers

<p>Exocytosis is the process by which large molecules are expelled from the cell, primarily observed in secretory cells such as those in glands.</p> Signup and view all the answers

<p>Receptor-mediated endocytosis involves receptor molecules binding to specific substances, leading to vesicle formation and transport into the cell.</p> Signup and view all the answers

<p>Isosmotic solutions do not change cell volume as there is no net movement of water across the membrane.</p> Signup and view all the answers

<p>The sodium-potassium pump transports Na+ out and K+ into the cell against their concentration gradients, using ATP, and is crucial for maintaining cellular ion balance.</p> Signup and view all the answers

<p>The primary energy source for primary active transport is ATP, which is directly utilized during the process of ATP hydrolysis.</p> Signup and view all the answers

<p>Facilitated diffusion is the passive transport of molecules across the membrane via carrier proteins, while active transport requires energy to move substances against their concentration gradient.</p> Signup and view all the answers

<p>Cells placed in a hypotonic solution will gain water, risking haemolysis or bursting.</p> Signup and view all the answers

<p>Secondary active transport uses the energy stored in the concentration gradients of ions, established by primary active transport (like the sodium-potassium pump), to move other substances against their gradients.</p> Signup and view all the answers

<p>The rate of movement during facilitated diffusion depends on the steepness of the concentration gradient and the number of available transporter proteins in the membrane.</p> Signup and view all the answers

<p>Antiporters move one ion in one direction while transporting another ion in the opposite direction, whereas symporters move two ions in the same direction, both using gradients created by primary active transport.</p> Signup and view all the answers

<p>Selective transport proteins ensure that only specific ions can pass through the membrane, thereby maintaining the essential electrochemical gradients vital for cellular functions.</p> Signup and view all the answers

<p>Ion channels allow specific ions to pass through the plasma membrane, facilitating the transport of charged particles across the lipid bilayer.</p> Signup and view all the answers

<p>Exocytosis involves the expulsion of substances from the cell, while endocytosis is the process of engulfing materials into the cell.</p> Signup and view all the answers

<p>Active transport mechanisms primarily use ATP as their energy source to move substances against their concentration gradient.</p> Signup and view all the answers

<p>Facilitated diffusion is a passive transport process that requires integral membrane proteins to help move water-soluble substances across the membrane.</p> Signup and view all the answers

<p>Osmosis is the movement of water from an area of low solute concentration to an area of high solute concentration, while diffusion pertains to the movement of any substance from high to low concentration.</p> Signup and view all the answers

<p>Lipid-soluble substances, such as respiratory gases (O2, CO2), small alcohols, and urea, can pass through the lipid bilayer via simple diffusion.</p> Signup and view all the answers

<p>The three types of passive transport include simple diffusion (lipid soluble), channel-mediated diffusion (water soluble), and facilitated diffusion (water soluble with carriers).</p> Signup and view all the answers

<p>Aquaporins are transmembrane proteins that function as channels specifically for the rapid transport of water molecules across the plasma membrane.</p> Signup and view all the answers

<p>Integral proteins span the entire width of the membrane and are involved in transport, whereas peripheral proteins are located on the inside or outside surface and provide structural support.</p> Signup and view all the answers

<p>Permeability of the plasma membrane is influenced by factors such as lipid solubility, molecular size, and the presence of driving forces like concentration gradients.</p> Signup and view all the answers

<p>Ion channels facilitate the passive movement of ions across the cell membrane, maintaining electrochemical gradients essential for processes like action potentials.</p> Signup and view all the answers

<p>Exocytosis is the process by which cells expel materials, while endocytosis involves the uptake of substances into the cell.</p> Signup and view all the answers

<p>Active transport is the process of moving substances against their concentration gradient using energy, typically in the form of ATP.</p> Signup and view all the answers

<p>Facilitated diffusion requires specific transport proteins to help move molecules across the membrane, while simple diffusion directly relies on the concentration gradient.</p> Signup and view all the answers

<p>Osmosis is the movement of water across a semipermeable membrane from an area of lower solute concentration to higher, helping maintain cellular turgor pressure.</p> Signup and view all the answers

<p>ATP is used as an energy source to power ion pumps that move ions against their concentration gradients.</p> Signup and view all the answers

<p>Facilitated diffusion occurs along the concentration gradient, meaning substances move from areas of high concentration to low without energy input.</p> Signup and view all the answers

<p>Isotonic solutions have equal solute concentrations on both sides of the membrane, hypertonic solutions have higher solute concentrations outside the cell, and hypotonic solutions have lower concentrations outside.</p> Signup and view all the answers

<p>The sodium-potassium pump actively transports sodium out and potassium into the cell, maintaining the electrochemical gradient necessary for nerve impulse transmission.</p> Signup and view all the answers

<p>Cells use endocytosis to engulf extracellular substances, forming vesicles that bring nutrients into the cell for energy production.</p> Signup and view all the answers

<p>The plasma membrane is primarily composed of phospholipids, proteins, and cholesterol.</p> Signup and view all the answers

<p>Cholesterol molecules provide rigidity to the membrane by inserting themselves between phospholipid molecules.</p> Signup and view all the answers

<p>Integral proteins span the entire width of the membrane and facilitate the transport of substances across it.</p> Signup and view all the answers

<p>Osmosis is the movement of water from a low solute concentration to a high solute concentration across a selectively permeable membrane.</p> Signup and view all the answers

<p>Water can pass through the plasma membrane by diffusion through the lipid bilayer or through aquaporins.</p> Signup and view all the answers

<p>Passive transport does not require energy and occurs along a concentration gradient, while active transport requires ATP and moves substances against a gradient.</p> Signup and view all the answers

<p>The three types of passive transport are simple diffusion, channel-mediated diffusion, and facilitated diffusion.</p> Signup and view all the answers

<p>Molecular size affects permeability as smaller molecules can more easily diffuse through the lipid bilayer or protein channels.</p> Signup and view all the answers

<p>A concentration gradient is typically the driving force for diffusion across the lipid bilayer.</p> Signup and view all the answers

<p>Peripheral proteins are attached to the inner or outer surface of the membrane and assist in signaling and structural support.</p> Signup and view all the answers

<p>Transporter proteins bind specifically to a solute on one side of the membrane and release it on the other side.</p> Signup and view all the answers

<p>A steeper concentration gradient increases the rate of facilitated diffusion, allowing more solutes to be transported quickly.</p> Signup and view all the answers

<p>Gated protein channels open and close in response to specific signals, whereas continuously open ion channels remain available for ion passage.</p> Signup and view all the answers

<p>ATP provides the energy required for primary active transport by undergoing hydrolysis to propel solutes against their concentration gradient.</p> Signup and view all the answers

<p>Secondary active transport utilizes the concentration gradients established by primary active transport to move other substances against their gradients.</p> Signup and view all the answers

<p>Exocytosis involves the movement of large molecules out of the cell via vesicles that fuse with the cell membrane.</p> Signup and view all the answers

<p>Antiporters transport two different ions or molecules in opposite directions, while symporters move them in the same direction across the membrane.</p> Signup and view all the answers

<p>The sodium-potassium pump maintains low sodium and high potassium concentrations inside cells, crucial for cell function.</p> Signup and view all the answers

<p>Solutes like glucose and fructose are commonly transported into and out of cells via facilitated diffusion.</p> Signup and view all the answers

<p>Solutes move from areas of higher concentration to lower concentration, with the rate increasing along a steeper gradient.</p> Signup and view all the answers

<p>The movement of a secretory vesicle towards the plasma membrane initiates neurotransmitter release.</p> Signup and view all the answers

<p>Endocytosis primarily facilitates the movement of large molecules and particles into the cell.</p> Signup and view all the answers

<p>Osmosis is the movement of water from low to high solute concentration, while simple diffusion involves the movement of solutes across a membrane.</p> Signup and view all the answers

<p>In a hypotonic solution, cells gain water and may swell or burst due to excess water intake.</p> Signup and view all the answers

<p>Receptor molecules on the cell's surface bind to specific substances, forming a vesicle that is taken into the cell.</p> Signup and view all the answers

<p>Osmotic pressure encourages water to move towards the solution with the highest concentration of solutes.</p> Signup and view all the answers

<p>In an isotonic solution, there is no net movement of water, so cells maintain their normal shape.</p> Signup and view all the answers

<p>Red blood cells in a hypertonic solution lose water, leading to crenation or cell dehydration.</p> Signup and view all the answers

<p>The fusion results in the release of the vesicle's contents into the extracellular fluid.</p> Signup and view all the answers

<p>Water moves from areas of lower solute concentration to areas of higher solute concentration.</p> Signup and view all the answers

<p>Glycolysis is the process that breaks down glucose anaerobically.</p> Signup and view all the answers

<p>ATP provides the energy necessary for muscle contraction, active transport, and cellular movement.</p> Signup and view all the answers

<p>Each cycle produces 2 CO2, 3 NADH, 1 ATP, and 1 FADH2.</p> Signup and view all the answers

<p>Aerobic respiration requires oxygen and produces more ATP, while anaerobic respiration occurs without oxygen and yields less ATP.</p> Signup and view all the answers

<p>NADH and FADH2 act as electron carriers, transporting electrons to the electron transport chain.</p> Signup and view all the answers

<p>Acetyl coenzyme A (acetyl CoA) is formed after pyruvic acid is decarboxylated.</p> Signup and view all the answers

<p>Energy is produced as electrons move through cytochromes, pumping H+ ions to create a proton gradient.</p> Signup and view all the answers

<p>The byproducts of glucose oxidation are CO2 and H2O.</p> Signup and view all the answers

<p>The net energy gain from glycolysis is 2 ATP and 2 NADH.</p> Signup and view all the answers

<p>The availability of oxygen determines its fate; if O2 is present, it enters the Krebs cycle; if not, it is converted to lactic acid.</p> Signup and view all the answers