11. ORGANISMS AND THERMAL ENERGY
509
principal over-all change in metabolism that is observed is an increase
in heat production. Hormones of the pituitary, adrenal, and thyroid
glands are involved in this process in a complex manner. Since it is
known that these hormones can cause changes in the level of various
enzymes in the animal, Potter (207) has suggested that metabolic cold
adaptation is due to a change in hydrogen transport from the usual
pathway to one or more alternative pathways, such as TPN oxidation,
in which phosphorylation does not occur efficiently and more energy is
dissipated as heat.
At the other end of the biokinetic temperature range, Kurtz (208)
has considered the problem of heat tolerance in plants. Desert plants
can survive and grow at temperatures similar to those endured by
thermophilic microorganisms. For example, Opuntia does not cease
growth until its internal temperature reaches 62°. After exposure to
such temperatures, growth resumes on cooling to 50°. Seeds of saguaro
cactus remain viable after 7 days at 83°. The author cites a number of
examples in which the ability to synthesize an essential metabolite is
the factor controlling the temperature range for growth in plants and
suggests that differences in heat tolerance between plants might derive
from the temperature characteristics of their synthetic enzymes, as has
previously been suggested for thermophilic microorganisms (4, 5).
References
1. A. K. Balls and H. Lineweaver, Food Research 3, 57-67 (1938).
2. I. W. Sizer and E. S. Josephson, Food Research 7, 201-209 (1942).
3. V. P. Maier and A. L. Tappel, Anal Chem. 26, 564-566 (1954).
4. M. B. Allen, /. Gen. Physiol 33, 205-214 (1950).
5. M. B. Allen, Bacteriol. Revs. 17, 125-173 (1953).
5a. H. Eyring, R. P. Boyce, and J. D. Spikes, this volume, Chapter 2.
6. I. W. Sizer, Advances in Enzymol 3, 35-62 (1943).
7. A. E. Stearn, Advances in Enzymol. 9, 25-74 (1949).
8. H. Eyring, /. Chem. Phys. 3, 107-115 (1935).
9. H. Eyring and A. E. Stearn, Chem. Revs. 24, 253-270 (1939).
10. F. W. Went, in "Vernalization and Photoperiodism, a Symposium" (F.
Verdoorn, ed.), pp. 145-157. Chronica Botanica, Waltham, Mass., 1948.
11. F. W. Went, "The Experimental Control of Plant Growth." Chronica Botanica,
Waltham, Mass., 1957.
12. H. Precht, J. Christophersen, and H. Hensel, "Temperatur und Leben."
Springer, Berlin, 1955.
13. I. D. Strelnikov, Compt. rend. 192, 1317-1319 (1931).
14. P. Krüger and F. Duspiva, Biol. Generaiis 9, 168-188 (1933).
15. H. Krogerus, Ada Zool. Fennica 53, 1-157 (1948).
16. D. A. Parry, /. Exptl Biol. 28, 445-462 (1951).
17. E. B. Edney, /. Exptl. Biol. 30, 331-349 (1953).
18. B. P. Uvarov, Trans. Roy. Entomol. Soc. (London) 79, 1-247 (1931).
19. C. Vorbrodt, Intern. Entomol. Z. 15, 162-163, 178-179, 202-206; 16, 10-14,
509
principal over-all change in metabolism that is observed is an increase
in heat production. Hormones of the pituitary, adrenal, and thyroid
glands are involved in this process in a complex manner. Since it is
known that these hormones can cause changes in the level of various
enzymes in the animal, Potter (207) has suggested that metabolic cold
adaptation is due to a change in hydrogen transport from the usual
pathway to one or more alternative pathways, such as TPN oxidation,
in which phosphorylation does not occur efficiently and more energy is
dissipated as heat.
At the other end of the biokinetic temperature range, Kurtz (208)
has considered the problem of heat tolerance in plants. Desert plants
can survive and grow at temperatures similar to those endured by
thermophilic microorganisms. For example, Opuntia does not cease
growth until its internal temperature reaches 62°. After exposure to
such temperatures, growth resumes on cooling to 50°. Seeds of saguaro
cactus remain viable after 7 days at 83°. The author cites a number of
examples in which the ability to synthesize an essential metabolite is
the factor controlling the temperature range for growth in plants and
suggests that differences in heat tolerance between plants might derive
from the temperature characteristics of their synthetic enzymes, as has
previously been suggested for thermophilic microorganisms (4, 5).
References
1. A. K. Balls and H. Lineweaver, Food Research 3, 57-67 (1938).
2. I. W. Sizer and E. S. Josephson, Food Research 7, 201-209 (1942).
3. V. P. Maier and A. L. Tappel, Anal Chem. 26, 564-566 (1954).
4. M. B. Allen, /. Gen. Physiol 33, 205-214 (1950).
5. M. B. Allen, Bacteriol. Revs. 17, 125-173 (1953).
5a. H. Eyring, R. P. Boyce, and J. D. Spikes, this volume, Chapter 2.
6. I. W. Sizer, Advances in Enzymol 3, 35-62 (1943).
7. A. E. Stearn, Advances in Enzymol. 9, 25-74 (1949).
8. H. Eyring, /. Chem. Phys. 3, 107-115 (1935).
9. H. Eyring and A. E. Stearn, Chem. Revs. 24, 253-270 (1939).
10. F. W. Went, in "Vernalization and Photoperiodism, a Symposium" (F.
Verdoorn, ed.), pp. 145-157. Chronica Botanica, Waltham, Mass., 1948.
11. F. W. Went, "The Experimental Control of Plant Growth." Chronica Botanica,
Waltham, Mass., 1957.
12. H. Precht, J. Christophersen, and H. Hensel, "Temperatur und Leben."
Springer, Berlin, 1955.
13. I. D. Strelnikov, Compt. rend. 192, 1317-1319 (1931).
14. P. Krüger and F. Duspiva, Biol. Generaiis 9, 168-188 (1933).
15. H. Krogerus, Ada Zool. Fennica 53, 1-157 (1948).
16. D. A. Parry, /. Exptl Biol. 28, 445-462 (1951).
17. E. B. Edney, /. Exptl. Biol. 30, 331-349 (1953).
18. B. P. Uvarov, Trans. Roy. Entomol. Soc. (London) 79, 1-247 (1931).
19. C. Vorbrodt, Intern. Entomol. Z. 15, 162-163, 178-179, 202-206; 16, 10-14,