Philodendron flowers pass electrons through a mitochondrial electron transport chain to generate heat. What step is bypassed in generating heat?
A. formation of a proton gradient
B. transfer of electrons to oxygen
C. excitation of electrons by sunlight
D. donation of electrons to the electron transport chain
E. release of electrons from water
A. formation of a proton gradient
You might also like to view...
As the resolution of a microscope system improves, the size of the smallest object that can be seen clearly
A. is smaller. B. is not affected. C. is larger.
A fish that has been salt-cured subsequently develops a reddish color. You suspect that the fish has been contaminated by the extreme halophile Halobacterium
Which of these features of cells removed from the surface of the fish, if confirmed, would support your suspicion? 1. the presence of the same photosynthetic pigments found in cyanobacteria 2. cell walls that lack peptidoglycan 3. cells that are isotonic to conditions on the surface of the fish 4. cells unable to survive salt concentrations lower than 9% 5. the presence of very large numbers of ion pumps in its plasma membrane A) 2 and 5 B) 3 and 4 C) 1, 4, and 5 D) 2, 3, 4, and 5
Among air-breathing animals, why do birds have the most effective mechanism of extracting oxygen from air?
a. because their air sacs provide additional respiratory surfaces b. because birds utilize crosscurrent exchange c. because bird lungs are the largest among vertebrates d. because bird lungs have more surface area
Which of the following is true about myosin I?
a. It is involved in muscle contraction. b. It has a long ?-helical tail through which it forms homodimers. c. It does not act as a molecular motor. d. It links the actin bundles to the plasma membrane in the microvilli of intestinal cells.