Bioinformatics Has Identified Some Enzymes Used in the Citric Acid

question 26

Multiple Choice

Bioinformatics has identified some enzymes used in the citric acid cycle in primitive bacteria.Once such a cycle utilized many of the citric acid cycle intermediates but occurred in the reverse direction.Researchers suspect which of the following based on this information?

• A)Researchers suspect that the "original" citric acid cycle was used by all species.
• B)Researchers suspect that portions of the reverse cycle may have been responsible for fixing CO₂
• C)Researchers suspect that early methods for converting pyruvate to acetyl CoA did not exist.
• D)Researchers suspect that the current "clockwise" version of the citric acid cycle could be used to help humans feed off CO₂.
• E)Researchers suspect that primitive prokaryotic use of the citric acid enzymes were focused on the production of CO₂ rather than the use of CO₂.

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Definitions:

Conversion Formula

A mathematical equation used to convert a quantity expressed in one set of units to another set of units.

Milligrams

A unit of mass in the metric system equal to one-thousandth of a gram.

Grams

A unit of mass in the metric system, used to measure small quantities of substances.