Refer to the Numbered Steps in the Figure When Answering

question 9

Multiple Choice

Refer to the numbered steps in the figure when answering the question. Two carbons in the form of acetyl- CoA enter the Krebs cycle by joining with oxaloacetic acid, a 4- carbon molecule. During which step does carbon leave the Krebs cycle in the form of CO₂?

• A) step 1
• B) step 3
• C) step 4
• D) step 1 and step 3 and step 4
• E) step 3 and step 4

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Definitions:

Rotary Motion

Movement in a circular path, revolving around an axis or center point.

Pressure Angle

The angle at which force is applied to the teeth of gears in mesh, affecting efficiency and strength of the gear teeth.

Radial Distance

The measure from the center of a circle to its perimeter, relevant in various contexts, including geometry and mechanical design.

Mating Tooth

In gear terminology, a tooth on one gear that engages with a corresponding tooth on a mating gear to transmit motion.