Bongkrekic acid is an antibiotic that inhibits the ATP/ADP transport protein in the inner mitochondrial membrane. Which of the following will allow electron transport to occur in mitochondria treated with bongkrekic acid?
(a) placing the mitochondria in anaerobic conditions
(b) adding FADH2
(c) making the inner membrane permeable to protons
(d) inhibiting the ATP synthase
(c) Inhibition of the ATP/ADP translocase prevents the export of ATP generated by oxidative phosphorylation in exchange for an import of ADP into the matrix. The ensuing buildup of ATP at the expense of ADP inhibits the ATP synthase. Because protons are no longer being used to power the ATP synthase, the proton gradient is not dissipated; the increasingly steep proton gradient makes it increasingly difficult for the electron-transport proteins to pump protons out of the matrix, and electron transport quickly stops. Hence, the inner membrane becomes permeable to protons, allowing electron transport to resume (although no ATP will be synthesized).
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Concerning the sex chromosomes, which of the
following is correct? a. The Y chromosome carries a greater number of genes for nonsexual traits than does the X. b. X and Y are different in size but carry nearly equal numbers of genes. c. The X chromosome carries more genes for nonsexual traits than does the Y. d. The X chromosome carries only gender-related genes. e. The X chromosome carries the SRY gene.
An organism can exchange matter and energy with its surroundings. Thus, any change in an organism's energy content
must be balanced by a corresponding change in the energy content of the surroundings. As such, an organism is referred to as a(n): a. closed system. b. open system. c. dynamic system. d. potential system. e. thermally reactive system
The structure in which meiosis occurs (which results in the formation of eggs) is the
A. cervix. B. ovary. C. vagina. D. uterus.
Which of the following nitrogenous bases is usually found in RNA but not in DNA?
A. Guanine B. Thymine C. Uracil D. Adenine