Related Concept Videos

Carrier-Mediated Transport01:06

Carrier-Mediated Transport

Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient.
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Glucose Transporters01:27

Glucose Transporters

Glucose transporters facilitate the transport of glucose across the cell membrane. In addition to glucose, some glucose transporters can also aid the movement of other hexoses such as fructose, mannose, and galactose.
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
ABC Transporters: Importer01:27

ABC Transporters: Importer

ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants.
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
ABC Transporters: Exporter01:31

ABC Transporters: Exporter

ATP-binding cassette or ABC transporter is the largest superfamily of integral membrane proteins. The transporters have transmembrane-binding domains (TMDs) and nucleotide-binding domains (NBDs). The TMDs are specific to their substrates, whereas the NBDs are similar to engines that complete ATP hydrolysis to complete the substrate transport. They can be full transporters consisting of two TMDs and NBDs, half transporters with one TMD and NBD, while some encoded with a single TMD or NBD are...
Secondary Active Transport01:32

Secondary Active Transport

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
Secondary Active Transport01:55

Secondary Active Transport

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...