HKIN 191 MIDTERM 1 EXAM QUESTIONS AND ANSWERS 2026

HKIN 191 MIDTERM 1 LATEST
EXAM
What is the electron transport chain? - ANSWERS-Is a sequence of
electron carrier molecules that shuttle electrons,
down a series of reactions that release energy; used to make ATP.


What is stage 1 of the aerobic system? - ANSWERS--conversion of
pyruvate/fatty acids/amino acids to acetyl-CoA
-one molecule of CO2 is produced
-if protein or fat is converted, an electron is released


What is stage 2 of the aerobic system? - ANSWERS--Acetyl-CoA enters
the Krebs cycle where it undergoes a series of chemical transformations
-molecules of CO2 are generated and electrons are stripped away
-electrons in the form of hydrogen are carried by NAD+ and FAD to
inner mitochondrial membrane


What is stage 3 of the aerobic system? - ANSWERS--electrons are
drawn to O2
-energy released by the flow of electrons pumps H+ to the inner
mitochondrial membrane space where they accumulate (stored potential
energy)

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, HKIN 191 MIDTERM 1 LATEST
EXAM
-stored potential energy transformed into energy used to re-synthesize
ATP as H+ passes through ATP synthase


What is oxidative phosphorylation? - ANSWERS-ATP re-synthesis in
the aerobic system


What is the fate of lactic acid? - ANSWERS--skeletal muscle uses
approx 72% of lactic acid produced as fuel
-18% is reconverted to glycogen in the liver and muscle
-8% converted to protein
-2% excreted in sweat and urine


What is the capacity and rate of the aerobic system? - ANSWERS-large
capacity and slow rate


How is lactic acid produced? - ANSWERS-if not enough O2 is available
to accept H+ and electrons from NADH, then they are accepted by
pyruvic acid to form lactic acid




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