BIOL 271: Module 2 Exam Review Questions With Complete Solutions

BIOL 271: Module 2 Exam Review Questions With
Complete Solutions


What is another term for the TCA?
The Krebs Cycle
What is the Krebs Cycle named after?
1953 Noble Prize-winning scientist Hans Krebs
What coenzyme does the Krebs Cycle require that is similar to
NAD?
FAD, Flavin adenine dinucleotide
What are the products of the Krebs Cycle?
- 2 ATP
- 6 NADH and 2 FADH2 (abundance of reduced electron
carriers)
What is the primary function of the TCA cycle?
to produce reduced electron carriers because the transfer of these
electrons will fuel the generation of ATP through the electron
transport system
The intermediate step in the TCA cycle, takes the pyruvate made
in glycolysis and converts it to _______. This eneters the
mitochondria in eukaryotic cells.
Acetyl-CoA
T/F:
The product of the Krebs Cycle is not ATP.

,True
The product of the Krebs Cycle is ________.
activated energy carriers
Activated energy carriers store _______ to bring to the _______
chain.
electrons; electron transport chain
The Krebs Cycle is called a cycle because the sequence of 8
reactions regenerates _______ acid, which is the necessary
_______ for the first reaction.
oxaloacetic; reactant
What is the electron transport system?
a continuation of cellular respiration and can proceed either
aerobically or anaerobically.
What is the electron transport system also. referred as?
ETC, electron transport chain
T/F:
Anaerobic respiration is less efficient and yields fewer ATP
molecules than aerobic respiration.
True
How does the Electron transport system work?
As electrons are transferred from NADH/FADH2 to terminal
electron acceptors, energy is released and captured by electron
acceptor proteins.

,Electrons are then passed down a chain of electron acceptors
(the naming comes from) causing proteins to be pumped out of
the membrane.
This causes a strong differential across the mitochondrial
membrane forming the proton motive force.
Where are electron transport proteins located?
the inner membrane of the mitochondria
What is pumped out of the membrane of the mitochondria when
the electrons are passed down the chain of electron acceptors?
Protons (H+)
What does the proton motive force do?
drives H+ back through the ATP synthase complex (located in
the membrane) resulting in the production of up to 34 molecules
of ATP
Cells require _______ to survive. The breakdown of _______ an
abundant and common source of energy, is often utilized by
various microbes.
ATP; glucose
Under aerobic conditions, the complete catabolism of glucose
yields ___ from glycolysis, ___ ATP from the TCA cycle, and
___ ATP from the electron transport system, for a total of ___
ATP from a single glucose molecule.
2; 2; 34; 38
What is the last stage of cellular respiration?

, The electron transport chain (ETC)
Where does the electron transport chain take place in eukaryotic
cells and prokaryotic cells?
In the inner membrane of the mitochondria in eukaryotic
cells and in the plasma membrane of prokaryotic cells.
Why is the ETC referred to as a chain?
the electron carriers embedded in the membrane make a
sequential system to keep passing along the electrons.
How does ETC work as a chain?
NADH and FADH2 donate their electrons to the ETC carriers.
In doing so, they become oxidized to NAD+ and FAD and can
pick up new electrons being generated by glycolysis and the
Krebs cycle.
What happens as the electrons in ETC move through the chain?
energy is released pumping H+ across the membrane building a
gradient with a higher concentration of H+ on one side of the
membrane.
What is the gradient in the ETC called?
Proton motive force
What type of energy does the proton motive force gradient
have?
Potential energy
What is the final electron acceptor in the chain?
Oxygen