618:, (HOOOH), which is an antibody-catalyzed product of singlet oxygen and water. This compound, in turn, disproportionates to ozone and peroxide, providing two powerful antibacterials. The body's range of defense against all of these active oxidizing agents is hardly surprising, then, given their "deliberate" employment as antimicrobial agents in the immune response. Reactive oxygen species also play an important role in the
292:
97:
in marine environments provide about 70% of the free oxygen produced on earth. The remainder is produced by terrestrial plants, although, for example, almost all oxygen produced in tropical forests is consumed by organisms living there.
547:
are molecules containing at least one oxygen atom and one or more unpaired electrons. Reactive oxygen species (ROS) are by-products of cell aerobic respiration. Important examples include; oxygen
606:
of higher organisms, however, create peroxide, superoxide, and singlet oxygen to destroy invading microbes. Recently, singlet oxygen has been found to be a source of biologically-produced
443:. The reaction for the aerobic respiration is essentially the reverse of photosynthesis, except that now there is a large release of chemical energy which is stored in
789:
Raval M, Biswal B, Biswal U (2005). "The mystery of oxygen evolution: analysis of structure and function of photosystem II, the water-plastoquinone oxido-reductase".
240:. Photosystem II therefore has also been referred to as water-plastoquinone oxido-reductase. The protons split off from the water molecules are released into the
994:
314:
into the serum of the blood, where some remains in direct relation to the partial pressure of gasses in the inhaled gas and the balance is bonded to
244:, thus contributing to the generation of a proton gradient across the thylakoid membrane. This proton gradient is the driving force for
252:
and couples the absorption of light energy and photolysis of water to the creation of chemical energy during photosynthesis. The O
686:
636:
271:(OEC) or water-splitting complex found associated with the lumenal side of thylakoid membranes. Manganese is an important
1100:
1052:
1015:
844:
773:
744:
698:
216:. The electrons extracted from the water molecules transfer to the electron-deficient high-energy state P680 of the
194:
oxidation of water to molecular oxygen and can be written as the following simplified chemical reaction: 2H
691:
Plants: the potentials for extracting protein, medicines, and other useful chemicals (workshop proceedings)
393:. Carbon dioxide, a waste product, is released from the cells and into the blood, where it is converted to
389:
reactions in the body. Oxygen that is suspended in the blood plasma equalizes into the tissue according to
17:
646:
374:). A liter of blood can dissolve 200 cc of oxygen gas, which is much more than water can dissolve.
440:
394:
191:
66:
382:
225:
385:, an enzyme that also has an active site with an atom of iron. Monooxygenase uses oxygen for many
666:
619:
544:
539:
295:
In all vertebrates, the heme group of hemoglobin binds most of the oxygen dissolved in the blood.
272:
268:
1044:
1036:
588:
444:
436:
245:
1071:
323:
342:
binds oxygen when it is present, changing hemoglobin's color from bluish red to bright red.
798:
584:
424:
249:
70:
715:
8:
611:
414:
398:
802:
970:
945:
822:
656:
311:
205:
860:
is released from another part of the hemoglobin molecule, as its acid, which causes CO
1096:
1075:
1064:
1048:
975:
840:
814:
769:
740:
694:
560:
402:
1089:
826:
1006:
965:
957:
839:
Holleman, A. F.; Wiberg, E. "Inorganic
Chemistry" Academic Press: San Diego, 2001.
806:
552:
428:
319:
187:
961:
1119:
1062:
Cook, Gerhard A.; Lauer, Carol M. (1968). "Oxygen". In
Clifford A. Hampel (ed.).
661:
256:
remaining after oxidation of the water molecule is released into the atmosphere.
241:
233:
580:
390:
315:
54:
810:
1113:
603:
237:
229:
94:
58:
979:
818:
631:
576:
572:
548:
432:
864:
to be released from bicarbonate, its major reservoir in blood plasma (see
946:"Role of mitochondrial reactive oxygen species in homeostasis regulation"
865:
651:
367:
300:
221:
209:
90:
62:
615:
556:
355:
347:
343:
339:
335:
86:
73:, oxygen is reduced to water, thus closing the biological water-oxygen
50:
42:
1010:
386:
363:
307:
260:
46:
768:. New York: W.H. Freeman and Company Publishers. pp. 115–127.
280:
922:
Figures given are for values up to 50 miles above the surface
763:
447:
molecules (up to 38 ATP molecules are formed from one molecule of
377:
After being carried in blood to a body tissue in need of oxygen, O
448:
371:
359:
276:
183:(or simply carbon dioxide + water + sunlight → glucose + oxygen)
1079:
641:
331:
264:
213:
133:
23:
607:
74:
334:, providing a higher oxygen-loading capacity. In blood, the
351:
303:, oxygen uptake is carried out by the following processes:
217:
1043:. Oxford, England, UK: Oxford University Press. pp.
764:
Raven, Peter H.; Ray F. Evert; Susan E. Eichhorn (2005).
291:
904:
455:
molecules). The simplified version of this reaction is:
894:
892:
890:
888:
886:
85:
In nature, free oxygen is produced by the light-driven
53:(light-driven oxidation and splitting) of water during
1041:
Nature's
Building Blocks: An A-Z Guide to the Elements
950:
Redox Report: Communications in Free
Radical Research
925:
871:
610:: This reaction proceeds through an unusual compound
883:
587:
to reduce superoxide radicals to hydrogen peroxide.
101:
A simplified overall formula for photosynthesis is:
45:
of living organisms. Free oxygen is produced in the
1088:
1063:
1014:
788:
687:"Marine Plants: A Unique and Unexplored Resource"
1111:
1070:. New York: Reinhold Book Corporation. pp.
350:in their blood to transport oxygen from their
286:
1095:(Revised ed.). Oxford University Press.
283:are also required for the reaction to occur.
943:
431:. Oxygen is used as an electron acceptor in
306:Following inhalation into the lungs, oxygen
208:of cyanobacteria as well as algal and plant
944:Zhang, Baoyi; et al. (December 2022).
435:to generate chemical energy in the form of
405:back to the lungs and the process repeats.
533:
1066:The Encyclopedia of the Chemical Elements
1061:
969:
910:
1086:
992:
877:
354:to their tissues, but other animals use
290:
41:) plays an important role in the energy
759:
757:
755:
753:
713:
684:
1112:
1034:
986:
931:
898:
591:and similar enzymes then convert the H
408:
637:Oxygen-haemoglobin dissociation curve
381:is handed off from the heme group to
190:during photosynthesis occurs via the
782:
750:
685:Fenical, William (September 1983).
622:of plants against pathogen attack.
13:
259:Water oxidation is catalyzed by a
224:, which have been removed into an
14:
1131:
693:. DIANE Publishing. p. 147.
80:
212:and requires the energy of four
89:during oxygenic photosynthesis.
937:
916:
850:
833:
766:Biology of Plants, 7th Edition
729:
707:
678:
1:
962:10.1080/13510002.2022.2046423
737:Chemistry The Central Science
672:
401:for transport to the lungs.
18:Geological history of oxygen
7:
716:"Breathing easy, Et tu, O2"
647:Apparent oxygen utilisation
625:
287:Oxygen uptake and transport
204:The reaction occurs in the
10:
1136:
537:
412:
15:
1087:Stwertka, Albert (1998).
811:10.1007/s11120-005-8163-4
441:oxidative phosphorylation
67:oxidative phosphorylation
993:Hoffmann, Roald (2004).
226:electron transport chain
791:Photosynthesis Research
735:Brown, LeMay, Burslen,
667:Reactive oxygen species
620:hypersensitive response
599:to water and dioxygen.
545:Reactive oxygen species
540:Reactive oxygen species
534:Reactive oxygen species
269:oxygen evolving complex
714:Broeker, W.S. (2006).
589:Glutathione peroxidase
437:adenosine triphosphate
324:coordination compounds
296:
228:after light-dependent
1091:Guide to the Elements
1035:Emsley, John (2001).
911:Cook & Lauer 1968
718:. Columbia University
559:anion radical (O2-),
294:
267:complex known as the
65:, and plants. During
16:Further information:
585:superoxide dismutase
425:cellular respiration
318:. They are bound to
250:photophosphorylation
71:cellular respiration
803:2005PhoRe..85..267R
612:dihydrogen trioxide
423:, is essential for
419:Molecular oxygen, O
415:Aerobic respiration
409:Aerobic respiration
399:binds to hemoglobin
206:thylakoid membranes
999:American Scientist
657:Oxygen catastrophe
320:dioxygen complexes
297:
87:splitting of water
1011:10.1511/2004.1.23
561:hydrogen peroxide
429:aerobic organisms
1127:
1106:
1094:
1083:
1069:
1058:
1028:
1027:
1025:
1024:
1018:
1013:. Archived from
995:"The Story of O"
990:
984:
983:
973:
941:
935:
929:
923:
920:
914:
908:
902:
896:
881:
875:
869:
854:
848:
837:
831:
830:
786:
780:
779:
761:
748:
733:
727:
726:
724:
723:
711:
705:
704:
682:
614:, also known as
583:. The body uses
553:hydroxyl radical
526:
524:
523:
513:
512:
511:
501:
500:
499:
489:
488:
487:
479:
478:
470:
469:
403:Blood circulates
232:and a series of
188:oxygen evolution
177:
176:
175:
165:
164:
163:
155:
154:
146:
145:
131:
129:
128:
118:
117:
116:
39:
38:
37:
1135:
1134:
1130:
1129:
1128:
1126:
1125:
1124:
1110:
1109:
1103:
1055:
1031:
1022:
1020:
991:
987:
942:
938:
930:
926:
921:
917:
909:
905:
897:
884:
876:
872:
863:
859:
855:
851:
838:
834:
787:
783:
776:
762:
751:
734:
730:
721:
719:
712:
708:
701:
683:
679:
675:
662:Oxygen toxicity
628:
598:
594:
570:
566:
542:
536:
522:
519:
518:
517:
515:
510:
507:
506:
505:
503:
498:
495:
494:
493:
491:
486:
483:
482:
481:
477:
474:
473:
472:
468:
465:
464:
463:
461:
454:
422:
417:
411:
380:
329:
316:red blood cells
289:
255:
242:thylakoid lumen
234:redox reactions
201:
198:O → 4e + 4H + O
197:
192:light-dependent
174:
171:
170:
169:
167:
162:
159:
158:
157:
153:
150:
149:
148:
144:
141:
140:
139:
137:
127:
124:
123:
122:
120:
115:
112:
111:
110:
108:
83:
36:
33:
32:
31:
29:
20:
12:
11:
5:
1133:
1123:
1122:
1108:
1107:
1101:
1084:
1059:
1053:
1030:
1029:
985:
936:
934:, p. 303.
924:
915:
913:, p. 500.
903:
901:, p. 298.
882:
870:
861:
857:
849:
832:
781:
774:
749:
728:
706:
699:
676:
674:
671:
670:
669:
664:
659:
654:
649:
644:
639:
634:
627:
624:
596:
592:
581:singlet oxygen
568:
564:
538:Main article:
535:
532:
531:
530:
529:
528:
520:
508:
496:
484:
475:
466:
452:
420:
410:
407:
378:
327:
326:that contain O
288:
285:
253:
248:synthesis via
222:Photosystem II
199:
195:
181:
180:
179:
178:
172:
160:
151:
142:
125:
113:
82:
81:Photosynthesis
79:
55:photosynthesis
34:
9:
6:
4:
3:
2:
1132:
1121:
1118:
1117:
1115:
1104:
1102:0-19-508083-1
1098:
1093:
1092:
1085:
1081:
1077:
1073:
1068:
1067:
1060:
1056:
1054:0-19-850340-7
1050:
1046:
1042:
1038:
1033:
1032:
1019:on 2007-02-22
1017:
1012:
1008:
1004:
1000:
996:
989:
981:
977:
972:
967:
963:
959:
955:
951:
947:
940:
933:
928:
919:
912:
907:
900:
895:
893:
891:
889:
887:
880:, p. 48.
879:
878:Stwertka 1998
874:
867:
853:
846:
845:0-12-352651-5
842:
836:
828:
824:
820:
816:
812:
808:
804:
800:
797:(3): 267–93.
796:
792:
785:
777:
775:0-7167-1007-2
771:
767:
760:
758:
756:
754:
746:
745:0-13-048450-4
742:
738:
732:
717:
710:
702:
700:1-4289-2397-7
696:
692:
688:
681:
677:
668:
665:
663:
660:
658:
655:
653:
650:
648:
645:
643:
640:
638:
635:
633:
630:
629:
623:
621:
617:
613:
609:
605:
604:immune system
602:Parts of the
600:
590:
586:
582:
578:
574:
562:
558:
554:
550:
549:free radicals
546:
541:
527:+ 2880 kJ/mol
460:
459:
458:
457:
456:
450:
446:
442:
439:(ATP) during
438:
434:
430:
426:
416:
406:
404:
400:
396:
392:
388:
384:
383:monooxygenase
375:
373:
370:(spiders and
369:
365:
361:
357:
353:
349:
345:
341:
337:
333:
325:
321:
317:
313:
309:
304:
302:
293:
284:
282:
278:
274:
270:
266:
262:
257:
251:
247:
243:
239:
238:plastoquinone
235:
231:
227:
223:
219:
215:
211:
207:
202:
193:
189:
184:
135:
106:
105:
104:
103:
102:
99:
96:
95:cyanobacteria
92:
88:
78:
76:
72:
68:
64:
60:
59:cyanobacteria
56:
52:
48:
44:
40:
26:
25:
19:
1090:
1065:
1040:
1021:. Retrieved
1016:the original
1002:
998:
988:
956:(1): 45–52.
953:
949:
939:
927:
918:
906:
873:
852:
835:
794:
790:
784:
765:
736:
731:
720:. Retrieved
709:
690:
680:
632:Oxygen cycle
601:
577:nitric oxide
573:hydroperoxyl
551:such as the
543:
433:mitochondria
418:
376:
346:animals use
322:, which are
305:
298:
263:-containing
258:
210:chloroplasts
203:
185:
182:
100:
84:
28:
22:
21:
932:Emsley 2001
899:Emsley 2001
866:Bohr effect
652:CO-oximeter
395:bicarbonate
391:Henry's law
368:hemerythrin
301:vertebrates
220:pigment of
186:Photolytic
91:Green algae
63:green algae
1023:2007-03-03
722:2007-10-21
673:References
616:trioxidane
575:radical,
557:superoxide
413:See also:
364:arthropods
356:hemocyanin
348:hemoglobin
344:Vertebrate
340:hemoglobin
336:heme group
230:excitation
51:photolysis
43:metabolism
1005:(1): 23.
579:(NO) and
387:oxidation
362:and some
261:manganese
47:biosphere
1114:Category
1080:68-29938
1037:"Oxygen"
980:35213291
827:12893308
819:16170631
747:, p. 958
626:See also
372:lobsters
360:molluscs
310:through
308:diffuses
281:chloride
273:cofactor
49:through
24:Dioxygen
1072:499–512
1045:297–304
971:8890532
799:Bibcode
555:(HO·),
451:and 6 O
449:glucose
427:in all
312:alveoli
277:calcium
214:photons
134:photons
77:cycle.
1120:Oxygen
1099:
1078:
1051:
978:
968:
843:
825:
817:
772:
743:
697:
642:Oxygen
332:ligand
275:, and
265:enzyme
823:S2CID
608:ozone
366:) or
352:lungs
330:as a
236:onto
75:redox
1097:ISBN
1076:LCCN
1049:ISBN
976:PMID
841:ISBN
815:PMID
770:ISBN
741:ISBN
695:ISBN
279:and
218:P680
93:and
1007:doi
966:PMC
958:doi
807:doi
571:),
514:+ 6
502:→ 6
490:+ 6
445:ATP
397:or
338:of
299:In
246:ATP
166:+ 6
119:+ 6
69:in
57:in
1116::
1074:.
1047:.
1039:.
1003:92
1001:.
997:.
974:.
964:.
954:27
952:.
948:.
885:^
856:CO
821:.
813:.
805:.
795:85
793:.
752:^
739:,
689:.
563:(H
504:CO
476:12
152:12
136:→
132:+
109:CO
61:,
1105:.
1082:.
1057:.
1026:.
1009::
982:.
960::
868:)
862:2
858:2
847:.
829:.
809::
801::
778:.
725:.
703:.
597:2
595:O
593:2
569:2
567:O
565:2
525:O
521:2
516:H
509:2
497:2
492:O
485:6
480:O
471:H
467:6
462:C
453:2
421:2
379:2
358:(
328:2
254:2
200:2
196:2
173:2
168:O
161:6
156:O
147:H
143:6
138:C
130:O
126:2
121:H
114:2
107:6
35:2
30:O
27:(
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