Chapter 5 - Active Transport

Biol 111

() happens when particles are being transported against their concentration gradient or electrochemical gradient; () is always required usually in the form of ATP; energy source can also be () gradient which is produced as a product of primary active transport

active transport, energy, electrochemical

Active transport occurs through transmembrane, integral () proteins; these are called (); there are three types: the () carries 1 molecule or ion; the () carries 2 different molecules or ions in the same direction; the () carries 2 different molecules or ions in different directions

carrier, pumps, uniporter, symporter, antiporter

() active transport moves an ion or molecule () its concentration gradient and uses energy from ATP ()

primary, up, hydrolysis

The sodium-potassium pump moves ions by binding three () ions to the pump's (), which is then phosphorylated by ATP, causing the pump to change shape and open to the exterior, releasing the sodium ions. Two () ions then bind from (), and the pump's dephosphorylation triggers another shape change, closing to the exterior and opening to the interior, releasing the potassium ions into the cell. The ions move () their respective concentration gradients

sodium, interior, potassium, outside, against

An () gradient is a gradient of ions across a membrane; arise from the combined effects of () and electrical gradients; cytoplasm contains more () charged molecules like ions and proteins than the extracellular fluid

electrochemical, concentration, negatively

An () pump is a transport protein that generates voltage across a membrane; () is the voltage difference across a membrane; important in the maintenance and functioning of our () system

electrogenic, membrane potential, nervous

() active transport moves an ion or molecule along its concentration gradient; its energy source is the () gradient; many amino acids and () enter the cell in this way

secondary, electrochemical, glucose

() transport is when cells need to import or export molecules/particles that are too large to pass through a transport protein like large proteins/macromolecules

bulk

() is the process by which a cell actively brings substances into itself by surrounding them with its membrane and forming a (); there are several types, including phagocytosis or cell (), pinocytosis or cell (), and ()-mediated endocytosis

endocytosis, vesicle, eating, drinking, receptor

() or “cell eating” is when the cell engulfs large particles, such as bacteria or debris; the vesicle merges with a () for breaking down the material

phagocytosis, lysosome

() or “cell drinking” is when the cell takes in droplets of extracellular fluid containing dissolved substances; the vesicle does not need to merge with a lysosome

pinocytosis

()-mediated endocytosis happens when specific molecules bind to receptors on the cell surface before being engulfed, allowing selective uptake

receptor

() is when substances that are packaged inside vesicles, often produced by the Golgi apparatus or endoplasmic reticulum move toward the cell membrane and are ()

exocytosis, expelled