963:. The tendency to dehydrate, or the facility to do this, is related to the size of the ion: larger ions can do it more easily that the smaller ions, so that a pore with weak polar centres will preferentially allow passage of larger ions over the smaller ones. When the interior of the channel is composed of polar groups from the side chains of the component amino acids, the interaction of a dehydrated ion with these centres can be more important than the facility for dehydration in conferring the specificity of the channel. For example, a channel made up of histidines and arginines, with positively charged groups, will selectively repel ions of the same polarity, but will facilitate the passage of negatively charged ions. Also, in this case, the smallest ions will be able to interact more closely due to the spatial arrangement of the molecule (stericity), which greatly increases the charge-charge interactions and therefore exaggerates the effect.
306:
834:
112:
metabolic energy in this case. For example, a classic chemical mechanism for separation that does not require the addition of external energy is dialysis. In this system a semipermeable membrane separates two solutions of different concentration of the same solute. If the membrane allows the passage of water but not the solute the water will move into the compartment with the greatest solute concentration in order to establish an
121:
872:
726:
980:. Partially charged non-electrolytes, that are more or less polar, such as ethanol, methanol or urea, are able to pass through the membrane through aqueous channels immersed in the membrane. There is no effective regulation mechanism that limits this transport, which indicates an intrinsic vulnerability of the cells to the penetration of these molecules.
952:
that a channel whose pore diameter was sufficient to allow the passage of one ion would also allow the transfer of others of smaller size, however, this does not occur in the majority of cases. There are two characteristics alongside size that are important in the determination of the selectivity of
792:
use is made of the gradients of certain solutes to transport a target compound against its gradient, causing the dissipation of the solute gradient. It may appear that, in this example, there is no energy use, but hydrolysis of the energy provider is required to establish the gradient of the solute
804:
The discovery of the existence of this type of transporter protein came from the study of the kinetics of cross-membrane molecule transport. For certain solutes it was noted that the transport velocity reached a plateau at a particular concentration above which there was no significant increase in
448:
The macromolecules on one side of the membrane can bond preferentially to a certain component of the membrane or chemically modify it. In this way, although the concentration of the solute may actually be different on both sides of the membrane, the availability of the solute is reduced in one of
111:
or against it. If the exchange of substances occurs in the direction of the gradient, that is, in the direction of decreasing potential, there is no requirement for an input of energy from outside the system; if, however, the transport is against the gradient, it will require the input of energy,
51:
embedded in them. The regulation of passage through the membrane is due to selective membrane permeability – a characteristic of biological membranes which allows them to separate substances of distinct chemical nature. In other words, they can be permeable to certain substances but not to others.
934:
As the main characteristic of transport through a biological membrane is its selectivity and its subsequent behavior as a barrier for certain substances, the underlying physiology of the phenomenon has been studied extensively. Investigation into membrane selectivity have classically been divided
116:
in which the energy of the system is at a minimum. This takes place because the water moves from a high solvent concentration to a low one (in terms of the solute, the opposite occurs) and because the water is moving along a gradient there is no need for an external input of energy.
917:
once the Na ions are liberated, the pump binds two molecules of K to their respective bonding sites on the extracellular face of the transport protein. This causes the dephosphorylation of the pump, reverting it to its previous conformational state, transporting the K ions into the
297:
form. This structure probably involves a conduit through hydrophilic protein environments that cause a disruption in the highly hydrophobic medium formed by the lipids. These proteins can be involved in transport in a number of ways: they act as pumps driven by
947:
The ionic channels define an internal diameter that permits the passage of small ions that is related to various characteristics of the ions that could potentially be transported. As the size of the ion is related to its chemical species, it could be assumed
129:
1. phospholipid 2. cholesterol 3. glycolipid 4. sugar 5. polytopic protein (transmembrane protein) 6. monotopic protein (here, a glycoprotein) 7. monotopic protein anchored by a phospholipid 8. peripheral monotopic protein (here, a
971:
Non-electrolytes, substances that generally are hydrophobic and lipophilic, usually pass through the membrane by dissolution in the lipid bilayer, and therefore, by passive diffusion. For those non-electrolytes whose transport through the membrane is
67:
is highly related to their capacities to attract different external elements, it is postulated that there is a group of specific transport proteins for each cell type and for every specific physiological stage. This differential expression is
693:
817:. Therefore, each transport protein has an affinity constant for a solute that is equal to the concentration of the solute when the transport velocity is half its maximum value. This is equivalent in the case of an enzyme to the
741:
of a system and decreases the free energy. The transport process is influenced by the characteristics of the transport substance and the nature of the bilayer. The diffusion velocity of a pure phospholipid membrane will depend on:
906:
ATP is hydrolyzed leading to phosphorylation of the cytoplasmic side of the pump, this induces a structure change in the protein. The phosphorylation is caused by the transfer of the terminal group of ATP to a residue of
568:
824:
Some important features of active transport in addition to its ability to intervene even against a gradient, its kinetics and the use of ATP, are its high selectivity and ease of selective pharmacological inhibition
841:
Secondary active transporter proteins move two molecules at the same time: one against a gradient and the other with its gradient. They are distinguished according to the directionality of the two molecules:
407:
849:(also called exchanger or counter-transporter): move a molecule against its gradient and at the same time displaces one or more ions along its gradient. The molecules move in opposite directions.
80:
coding for these proteins and its translation, for instance, through genetic-molecular mechanisms, but also at the cell biology level: the production of these proteins can be activated by
773:
In active transport a solute is moved against a concentration or electrochemical gradient; in doing so the transport proteins involved consume metabolic energy, usually ATP. In
597:
will be negative, that is, it will favor the transport of cations from the interior of the cell. So, if the potential difference is maintained, the equilibrium state Δ
424:
is negative, and the process is thermodynamically favorable. As the energy is transferred from one compartment to another, except where other factors intervene, an
777:
the hydrolysis of the energy provider (e.g. ATP) takes place directly in order to transport the solute in question, for instance, when the transport proteins are
620:
914:
the structure change in the pump exposes the Na to the exterior. The phosphorylated form of the pump has a low affinity for Na ions so they are released.
798:
154:
of substances through the membrane without expending metabolic energy and without the aid of transport proteins. If the transported substance has a net
883:
A pump is a protein that hydrolyses ATP to transport a particular solute through a membrane, and in doing so, generating an electrochemical gradient
1206:
988:
There are several databases which attempt to construct phylogenetic trees detailing the creation of transporter proteins. One such resource is the
855:: move a molecule against its gradient while displacing one or more different ions along their gradient. The molecules move in the same direction.
463:
456:
can exist which can influence ion distribution. For example, for the transport of ions from the exterior to the interior, it is possible that:
440: = 0. However, there are three circumstances under which this equilibrium will not be reached, circumstances which are vital for the
294:
1373:
324:
A general principle of thermodynamics that governs the transfer of substances through membranes and other surfaces is that the exchange of
806:
285:
As few molecules are able to diffuse through a lipid membrane the majority of the transport processes involve transport proteins. These
309:
Transport of substances across the plasma membrane can be via passive transport (simple and facilitated diffusion) or active transport.
959:
In order for an ion to pass through a pore it must dissociate itself from the water molecules that cover it in successive layers of
921:
The unphosphorylated form of the pump has a higher affinity for Na ions than K ions, so the two bound K ions are released into the
1579:
1258:"A comprehensive approach to the mathematical modeling of mass transport in biological systems: Fundamental concepts and models"
1167:"A comprehensive approach to the mathematical modeling of mass transport in biological systems: Fundamental concepts and models"
733:
separates two compartments of different solute concentrations: over time, the solute will diffuse until equilibrium is reached.
350:
1503:
989:
813:
by the formation of a substrate-transporter complex, which is conceptually the same as the enzyme-substrate complex of
322:
principles. Membrane transport obeys physical laws that define its capabilities and therefore its biological utility.
1313:
1240:
1149:
1119:
1094:
1069:
1041:
1366:
891:. In terms of membrane transport the gradient is of interest as it contributes to decreased system entropy in the
1523:
818:
1572:
1257:
1166:
601: = 0 will not correspond to an equimolar concentration of ions on both sides of the membrane.
1657:
1359:
100:
Thermodynamically the flow of substances from one compartment to another can occur in the direction of a
56:
1471:
887:. This gradient is of interest as an indicator of the state of the cell through parameters such as the
785:
449:
the compartments to such an extent that, for practical purposes, no gradient exists to drive transport.
59:
which are specialized to varying degrees in the transport of specific molecules. As the diversity and
1748:
1648:
1466:
774:
159:
73:
1565:
92:
vesicles. The cell membrane regulates the transport of materials entering and exiting the cell.
1661:
1643:
730:
299:
286:
263:
1329:
1697:
1652:
1433:
1418:
1274:
1200:
1183:
977:
896:
895:
of substances against their gradient. One of the most important pumps in animal cells is the
876:
574:
425:
113:
688:{\displaystyle \Delta G=RT\log {\frac {C_{\text{inside}}}{C_{\text{outside}}}}+\Delta G^{b}}
40:
8:
1392:
702:
corresponds to a favorable thermodynamic reaction, such as the hydrolysis of ATP, or the
271:
1412:
1279:
1188:
1000:
973:
884:
810:
453:
305:
163:
613:
will be modified. This situation is common in active transport and is described thus:
1702:
1400:
1309:
1283:
1236:
1192:
1145:
1115:
1114:(McGraw-Hill Interamericana de España, S.A.U. ed.). McGraw-Hill Interamericana.
1090:
1065:
1037:
737:
As mentioned above, passive diffusion is a spontaneous phenomenon that increases the
720:
325:
155:
147:
1717:
1635:
1443:
1408:
1269:
1178:
888:
788:, use is made of the energy stored in an electrochemical gradient. For example, in
768:
20:
1557:
903:
binding of three Na ions to their active sites on the pump which are bound to ATP.
1712:
1302:
860:
814:
105:
158:, it will move not only in response to a concentration gradient, but also to an
1597:
81:
64:
44:
976:
by a transport protein the ability to diffuse is, generally, dependent on the
1742:
1722:
1682:
1605:
1589:
1544:
1498:
797:
solute will be generated through the use of certain types of proteins called
319:
290:
125:
101:
784:. Where the hydrolysis of the energy provider is indirect as is the case in
563:{\displaystyle \Delta G=RT\log {\frac {C_{inside}}{C_{outside}}}+ZF\Delta P}
293:
immersed in the lipid matrix. In bacteria these proteins are present in the
1620:
1610:
1528:
1508:
936:
892:
794:
789:
703:
1615:
1518:
1513:
1490:
1428:
1005:
954:
333:
302:, that is, by metabolic energy, or as channels of facilitated diffusion.
143:
139:
135:
89:
85:
1692:
1687:
1538:
1461:
1036:(Buenos Aires: MĂ©dica Panamericana ed.). Ed. MĂ©dica Panamericana.
846:
267:
120:
60:
1164:
318:
A physiological process can only take place if it complies with basic
170:
Relative permeability of a phospholipid bilayer to various substances
134:
The nature of biological membranes, especially that of its lipids, is
1456:
1451:
1351:
1139:
960:
957:
and the interaction of the ion with the internal charges of the pore.
908:
852:
151:
69:
36:
833:
27:
refers to the collection of mechanisms that regulate the passage of
1727:
1677:
236:
108:
55:
The movements of most solutes through the membrane are mediated by
48:
809:
type response. This was interpreted as showing that transport was
1481:
1423:
922:
781:
738:
232:
219:
28:
793:
transported along with the target compound. The gradient of the
340:
in a compartment to another compartment where it is present at C
1707:
1625:
1230:
778:
871:
837:
Uniport, symport, and antiport of molecules through membranes.
706:
of a compound that is moved in the direction of its gradient.
582:
215:
146:
layer. This structure makes transport possible by simple or
77:
725:
589:
is negative and Z is positive, the contribution of the term
911:
in the transport protein and the subsequent release of ADP.
211:
32:
983:
714:
828:
1333:
402:{\displaystyle \Delta G=RT\log {\frac {C_{2}}{C_{1}}}}
623:
609:
is coupled to the transport process then the global Δ
466:
353:
1089:(in Spanish) (Reverté ediciones ed.). Reverte.
1587:
1064:(Barcelona: Omega ed.). Ediciones Omega, S.a.
1301:
1140:Mathews C. K.; Van Holde, K.E; Ahern, K.G (2003).
687:
562:
401:
1299:
1255:
899:, that operates through the following mechanism:
138:, as they form bilayers that contain an internal
1740:
1308:(Worth Publishers ed.). Worth Publishers.
1262:International Journal of Heat and Mass Transfer
1171:International Journal of Heat and Mass Transfer
1165:Zaheri, Shadi and Hassanipour, Fatemeh (2020).
1109:
966:
1573:
1367:
1256:Zaheri, Shadi; Hassanipour, Fatemeh (2020).
1231:Randall D; Burggren, W.; French, K. (1998).
1205:: CS1 maint: multiple names: authors list (
1084:
1295:
1293:
16:Transportation of solutes through membranes
1580:
1566:
1391:Mechanisms for chemical transport through
1374:
1360:
942:
925:. ATP binds, and the process starts again.
762:
1273:
1182:
1135:
1133:
1131:
1055:
1053:
755:charge, if the molecule has a net charge.
1290:
1275:10.1016/j.ijheatmasstransfer.2020.119777
1226:
1224:
1222:
1220:
1218:
1216:
1184:10.1016/j.ijheatmasstransfer.2020.119777
1027:
1025:
1023:
1021:
870:
832:
724:
304:
119:
1103:
1059:
984:Creation of membrane transport proteins
929:
1741:
1381:
1128:
1050:
1031:
715:Passive diffusion and active diffusion
1561:
1355:
1330:"Transporter Classification Database"
1213:
1018:
953:the membrane pores: the facility for
829:Secondary active transporter proteins
444:functioning of biological membranes:
1504:Non-specific, adsorptive pinocytosis
88:level, or even by being situated in
1144:(3rd ed.). Pearson Education.
990:Transporter Classification database
13:
1304:Principles of Biochemistry, 2nd Ed
709:
672:
624:
554:
467:
354:
14:
1760:
336:of a substance of concentration C
313:
229:Large uncharged polar molecules
224:Permeable, totally or partially
208:Small uncharged polar molecules
1322:
1087:FĂsica para ciencias de la vida
1062:BiologĂa molecular de la cĂ©lula
244:
206:
1249:
1158:
1078:
605:If a process with a negative Δ
1:
1524:Receptor-mediated endocytosis
1060:Alberts; et al. (2004).
1011:
879:showing alpha and beta units.
454:membrane electrical potential
95:
1034:BiologĂa celular y molecular
1032:Lodish; et al. (2005).
7:
1658:Peripheral membrane protein
994:
967:Non-electrolyte selectivity
859:Both can be referred to as
82:cellular signaling pathways
57:membrane transport proteins
10:
1765:
1649:Integral membrane proteins
1472:Secondary active transport
1300:Lehninger, Albert (1993).
805:uptake rate, indicating a
786:secondary active transport
766:
718:
581:the membrane potential in
289:possess a large number of
1670:
1634:
1596:
1537:
1489:
1480:
1442:
1399:
1389:
819:Michaelis–Menten constant
332:, for the transport of a
72:through the differential
1467:Primary active transport
1233:Eckert FisiologĂa animal
875:Simplified diagram of a
866:
775:primary active transport
260:Charged polar molecules
160:electrochemical gradient
150:, which consists of the
1693:Lipid raft/microdomains
1110:Prescott, L.M. (1999).
978:partition coefficient K
943:Electrolyte selectivity
935:into those relating to
763:Active and co-transport
746:concentration gradient,
428:will be reached where C
1698:Membrane contact sites
1662:Lipid-anchored protein
1644:Membrane glycoproteins
939:and non-electrolytes.
880:
838:
734:
731:semipermeable membrane
689:
564:
403:
310:
287:transmembrane proteins
142:layer and an external
131:
1653:transmembrane protein
1419:Facilitated diffusion
1085:Cromer, A.H. (1996).
897:sodium potassium pump
877:sodium potassium pump
874:
836:
728:
690:
565:
404:
308:
123:
1678:Caveolae/Coated pits
1393:biological membranes
930:Membrane selectivity
621:
464:
351:
41:biological membranes
272:glucose-6-phosphate
171:
1703:Membrane nanotubes
1588:Structures of the
1413:mediated transport
1383:Membrane transport
1001:Cellular transport
885:membrane potential
881:
839:
735:
685:
575:Faraday's constant
560:
399:
311:
175:Type of substance
169:
164:membrane potential
132:
25:membrane transport
1736:
1735:
1636:Membrane proteins
1555:
1554:
1551:
1550:
1401:Passive transport
1336:on 3 January 2014
799:biochemical pumps
721:Passive transport
667:
664:
654:
543:
397:
280:
279:
156:electrical charge
148:passive diffusion
1756:
1749:Membrane biology
1718:Nuclear envelope
1713:Nodes of Ranvier
1582:
1575:
1568:
1559:
1558:
1487:
1486:
1444:Active transport
1409:Simple diffusion
1376:
1369:
1362:
1353:
1352:
1346:
1345:
1343:
1341:
1332:. Archived from
1326:
1320:
1319:
1307:
1297:
1288:
1287:
1277:
1253:
1247:
1246:
1235:(4th ed.).
1228:
1211:
1210:
1204:
1196:
1186:
1162:
1156:
1155:
1137:
1126:
1125:
1107:
1101:
1100:
1082:
1076:
1075:
1057:
1048:
1047:
1029:
889:Nernst potential
769:Active transport
694:
692:
691:
686:
684:
683:
668:
666:
665:
662:
656:
655:
652:
646:
569:
567:
566:
561:
544:
542:
541:
514:
513:
489:
408:
406:
405:
400:
398:
396:
395:
386:
385:
376:
172:
168:
63:of the distinct
21:cellular biology
1764:
1763:
1759:
1758:
1757:
1755:
1754:
1753:
1739:
1738:
1737:
1732:
1666:
1630:
1598:Membrane lipids
1592:
1586:
1556:
1547:
1533:
1476:
1438:
1395:
1385:
1380:
1350:
1349:
1339:
1337:
1328:
1327:
1323:
1316:
1298:
1291:
1254:
1250:
1243:
1229:
1214:
1198:
1197:
1163:
1159:
1152:
1138:
1129:
1122:
1108:
1104:
1097:
1083:
1079:
1072:
1058:
1051:
1044:
1030:
1019:
1014:
997:
986:
969:
958:
945:
932:
869:
861:co-transporters
831:
815:enzyme kinetics
771:
765:
749:hydrophobicity,
723:
717:
712:
710:Transport types
679:
675:
661:
657:
651:
647:
645:
622:
619:
618:
519:
515:
494:
490:
488:
465:
462:
461:
435:
431:
419:
415:
391:
387:
381:
377:
375:
352:
349:
348:
343:
339:
323:
316:
282:
252:
200:
196:
192:
128:
106:electrochemical
98:
17:
12:
11:
5:
1762:
1752:
1751:
1734:
1733:
1731:
1730:
1725:
1723:Phycobilisomes
1720:
1715:
1710:
1705:
1700:
1695:
1690:
1685:
1683:Cell junctions
1680:
1674:
1672:
1668:
1667:
1665:
1664:
1655:
1646:
1640:
1638:
1632:
1631:
1629:
1628:
1623:
1618:
1613:
1608:
1602:
1600:
1594:
1593:
1585:
1584:
1577:
1570:
1562:
1553:
1552:
1549:
1548:
1543:
1541:
1535:
1534:
1532:
1531:
1526:
1521:
1516:
1511:
1506:
1501:
1495:
1493:
1484:
1478:
1477:
1475:
1474:
1469:
1464:
1459:
1454:
1448:
1446:
1440:
1439:
1437:
1436:
1431:
1426:
1421:
1416:
1405:
1403:
1397:
1396:
1390:
1387:
1386:
1379:
1378:
1371:
1364:
1356:
1348:
1347:
1321:
1314:
1289:
1248:
1241:
1212:
1157:
1150:
1127:
1120:
1102:
1095:
1077:
1070:
1049:
1042:
1016:
1015:
1013:
1010:
1009:
1008:
1003:
996:
993:
985:
982:
968:
965:
944:
941:
931:
928:
927:
926:
919:
915:
912:
904:
868:
865:
857:
856:
850:
830:
827:
795:co-transported
767:Main article:
764:
761:
760:
759:
756:
753:
750:
747:
719:Main article:
716:
713:
711:
708:
696:
695:
682:
678:
674:
671:
660:
650:
644:
641:
638:
635:
632:
629:
626:
615:
614:
571:
570:
559:
556:
553:
550:
547:
540:
537:
534:
531:
528:
525:
522:
518:
512:
509:
506:
503:
500:
497:
493:
487:
484:
481:
478:
475:
472:
469:
458:
457:
450:
433:
429:
417:
416:is less than C
413:
410:
409:
394:
390:
384:
380:
374:
371:
368:
365:
362:
359:
356:
341:
337:
315:
314:Thermodynamics
312:
278:
277:
276:Not permeable
274:
261:
257:
256:
255:Not permeable
253:
250:
249:K, Na, Cl, HCO
247:
243:
242:
241:Not permeable
239:
230:
226:
225:
222:
209:
205:
204:
201:
198:
194:
190:
187:
183:
182:
179:
176:
130:glycoprotein.)
97:
94:
45:lipid bilayers
15:
9:
6:
4:
3:
2:
1761:
1750:
1747:
1746:
1744:
1729:
1726:
1724:
1721:
1719:
1716:
1714:
1711:
1709:
1708:Myelin sheath
1706:
1704:
1701:
1699:
1696:
1694:
1691:
1689:
1686:
1684:
1681:
1679:
1676:
1675:
1673:
1669:
1663:
1659:
1656:
1654:
1650:
1647:
1645:
1642:
1641:
1639:
1637:
1633:
1627:
1624:
1622:
1621:Sphingolipids
1619:
1617:
1614:
1612:
1611:Phospholipids
1609:
1607:
1606:Lipid bilayer
1604:
1603:
1601:
1599:
1595:
1591:
1590:cell membrane
1583:
1578:
1576:
1571:
1569:
1564:
1563:
1560:
1546:
1545:Degranulation
1542:
1540:
1536:
1530:
1527:
1525:
1522:
1520:
1517:
1515:
1512:
1510:
1507:
1505:
1502:
1500:
1499:Efferocytosis
1497:
1496:
1494:
1492:
1488:
1485:
1483:
1479:
1473:
1470:
1468:
1465:
1463:
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1432:
1430:
1427:
1425:
1422:
1420:
1417:
1414:
1410:
1407:
1406:
1404:
1402:
1398:
1394:
1388:
1384:
1377:
1372:
1370:
1365:
1363:
1358:
1357:
1354:
1335:
1331:
1325:
1317:
1315:0-87901-711-2
1311:
1306:
1305:
1296:
1294:
1285:
1281:
1276:
1271:
1267:
1263:
1259:
1252:
1244:
1242:84-486-0200-5
1238:
1234:
1227:
1225:
1223:
1221:
1219:
1217:
1208:
1202:
1194:
1190:
1185:
1180:
1176:
1172:
1168:
1161:
1153:
1151:84-7829-053-2
1147:
1143:
1136:
1134:
1132:
1123:
1121:84-486-0261-7
1117:
1113:
1112:MicrobiologĂa
1106:
1098:
1096:84-291-1808-X
1092:
1088:
1081:
1073:
1071:84-282-1351-8
1067:
1063:
1056:
1054:
1045:
1043:950-06-1374-3
1039:
1035:
1028:
1026:
1024:
1022:
1017:
1007:
1004:
1002:
999:
998:
992:
991:
981:
979:
975:
964:
962:
956:
951:
940:
938:
924:
920:
916:
913:
910:
905:
902:
901:
900:
898:
894:
890:
886:
878:
873:
864:
862:
854:
851:
848:
845:
844:
843:
835:
826:
822:
820:
816:
812:
808:
802:
800:
796:
791:
787:
783:
780:
776:
770:
757:
754:
751:
748:
745:
744:
743:
740:
732:
727:
722:
707:
705:
701:
680:
676:
669:
658:
648:
642:
639:
636:
633:
630:
627:
617:
616:
612:
608:
604:
603:
602:
600:
596:
592:
588:
584:
580:
576:
557:
551:
548:
545:
538:
535:
532:
529:
526:
523:
520:
516:
510:
507:
504:
501:
498:
495:
491:
485:
482:
479:
476:
473:
470:
460:
459:
455:
451:
447:
446:
445:
443:
439:
436:, and where Δ
427:
423:
392:
388:
382:
378:
372:
369:
366:
363:
360:
357:
347:
346:
345:
335:
331:
327:
321:
320:thermodynamic
307:
303:
301:
296:
292:
291:alpha helices
288:
283:
275:
273:
269:
265:
262:
259:
258:
254:
248:
245:
240:
238:
234:
231:
228:
227:
223:
221:
217:
213:
210:
207:
202:
188:
185:
184:
180:
177:
174:
173:
167:
165:
161:
157:
153:
149:
145:
141:
137:
127:
126:cell membrane
124:Diagram of a
122:
118:
115:
110:
107:
103:
102:concentration
93:
91:
87:
83:
79:
75:
74:transcription
71:
66:
62:
58:
53:
50:
47:that contain
46:
42:
38:
34:
30:
26:
22:
1616:Lipoproteins
1529:Transcytosis
1509:Phagocytosis
1382:
1338:. Retrieved
1334:the original
1324:
1303:
1265:
1261:
1251:
1232:
1201:cite journal
1174:
1170:
1160:
1141:
1111:
1105:
1086:
1080:
1061:
1033:
987:
970:
949:
946:
937:electrolytes
933:
893:co-transport
882:
858:
840:
823:
803:
790:co-transport
772:
736:
704:co-transport
699:
697:
610:
606:
598:
594:
590:
586:
578:
572:
441:
437:
421:
411:
329:
317:
284:
281:
133:
99:
54:
43:, which are
24:
18:
1519:Potocytosis
1514:Pinocytosis
1491:Endocytosis
1006:Scramblases
955:dehydration
758:temperature
573:Where F is
426:equilibrium
326:free energy
295:beta lamina
268:amino acids
162:due to the
144:hydrophilic
140:hydrophobic
136:amphiphilic
114:equilibrium
90:cytoplasmic
86:biochemical
1688:Glycocalyx
1539:Exocytosis
1462:Antiporter
1268:: 199777.
1177:: 119777.
1142:BioquĂmica
1012:References
847:antiporter
203:Permeable
181:Behaviour
96:Background
61:physiology
35:and small
1728:Porosomes
1457:Symporter
1452:Uniporter
1284:225223363
1193:225223363
961:solvation
909:aspartate
853:symporter
807:log curve
673:Δ
643:
625:Δ
555:Δ
486:
468:Δ
373:
355:Δ
178:Examples
152:diffusion
84:, at the
70:regulated
37:molecules
1743:Category
1434:Carriers
1429:Channels
1411:(or non-
995:See also
974:mediated
950:a priori
811:mediated
237:fructose
109:gradient
49:proteins
39:through
31:such as
1626:Sterols
1482:Cytosis
1424:Osmosis
1340:15 July
923:cytosol
782:enzymes
739:entropy
698:Where Δ
663:outside
585:. If Δ
442:in vivo
233:glucose
220:ethanol
76:of the
29:solutes
1312:
1282:
1239:
1191:
1148:
1118:
1093:
1068:
1040:
779:ATPase
653:inside
412:When C
186:Gases
1671:Other
1280:S2CID
1189:S2CID
918:cell.
867:Pumps
752:size,
583:volts
577:and Δ
246:Ions
216:water
78:genes
65:cells
1342:2010
1310:ISBN
1237:ISBN
1207:link
1146:ISBN
1116:ISBN
1091:ISBN
1066:ISBN
1038:ISBN
593:to Δ
591:ZFΔP
344:is:
334:mole
212:Urea
33:ions
1270:doi
1266:158
1179:doi
1175:158
640:log
483:log
420:, Δ
370:log
328:, Δ
300:ATP
264:ATP
197:, O
193:, N
104:or
19:In
1745::
1292:^
1278:.
1264:.
1260:.
1215:^
1203:}}
1199:{{
1187:.
1173:.
1169:.
1130:^
1052:^
1020:^
863:.
821:.
801:.
729:A
452:A
432:=C
270:,
266:,
235:,
218:,
214:,
189:CO
166:.
23:,
1660:/
1651:/
1581:e
1574:t
1567:v
1415:)
1375:e
1368:t
1361:v
1344:.
1318:.
1286:.
1272::
1245:.
1209:)
1195:.
1181::
1154:.
1124:.
1099:.
1074:.
1046:.
700:G
681:b
677:G
670:+
659:C
649:C
637:T
634:R
631:=
628:G
611:G
607:G
599:G
595:G
587:P
579:P
558:P
552:F
549:Z
546:+
539:e
536:d
533:i
530:s
527:t
524:u
521:o
517:C
511:e
508:d
505:i
502:s
499:n
496:i
492:C
480:T
477:R
474:=
471:G
438:G
434:1
430:2
422:G
418:1
414:2
393:1
389:C
383:2
379:C
367:T
364:R
361:=
358:G
342:2
338:1
330:G
251:3
199:2
195:2
191:2
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