Bio 1313 Chapter 6
Pyruvate
forms at the end of glycolysis
In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as __________. These other stages occur in the __________.
ATP ... mitochondria
During chemiosmosis,
ATP is synthesized when H+ ions move through a channel in ATP synthase.
Structure A is _____.
ATP synthase
The overall equation for the cellular respiration of glucose is
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy.
The O2 required for __________ is supplied by __________.
Cellular Respiration; Breathing
Lungs are to breathing as _____ are to cellular respiration.
Mitochondria
What molecule is indicated by the letter D?
Oxygen
What is the role of oxygen in cellular respiration?
Oxygen accepts high-energy electrons after they are stripped from glucose.
Which of these enters the citric acid cycle (also called the Krebs cycle)?
acetyl CoA
The electron transport chain is, in essence, a series of redox reactions that conclude cellular respiration. During these redox reactions, __________.
electrons are transferred through a series of electron acceptors embedded within the inner mitochondrial membrane
In cellular respiration, glucose _____ electrons, whereas _____ electrons.
loses ... oxygen gains
Primarily, cellular respiration serves to _____.
make ATP to power the cell's activities
The electron transport chain is a series of electron carrier molecules. In eukaryotes, where can this structure be found?
mitochondria
The enzymes of the citric acid cycle are located in the
mitochondrial matrix and inner mitochondrial membrane.
Where do the reactions of the citric acid cycle occur in eukaryotic cells?
mitochondrion
After glycolysis but before the citric acid cycle,
pyruvate is oxidized
Cellular respiration accomplishes two major processes: (1) it breaks glucose down into smaller molecules, and (2) it harvests the chemical energy released and stores it in ATP molecules. By the end of _____, the breakdown of glucose is complete; most ATP molecules are produced during _____.
the Citric Acid cycle ... electron transport
The proximate (immediate) source of energy for oxidative phosphorylation is _____.
kinetic energy that is released as hydrogen ions diffuse down their concentration gradient
A molecule that functions as the electron donor in a redox reaction __________.
loses electrons and becomes oxidized
For each glucose that enters glycolysis, _____ NADH enter the electron transport chain.
total of 10 NADH are produced -- (2 in glycolysis, 2 in acetyl CoA production, and 6 in the citric acid cycle.)
In cellular respiration, which of the following outcomes is the result of electrons moving through the electron transport chain (or its components)?
A proton gradient is formed. (The energy released by the electron transport chain is used to create a proton gradient across the inner mitochondrial membrane. This allows the production of ATP by chemiosmosis.)
In glycolysis, what starts the process of glucose breakdown?
ATP
The energy released from the redox reactions in the electron transport chain is used by the cell to make ___
ATP
best describe the electron transport chain?
Electrons pass from one carrier to another, releasing a little energy at each step.
Which of these is NOT a product of glycolysis?
FADH2
In cellular respiration, organic molecules become oxidized as ____ picks up electrons and H+ and becomes reduced to NADH.
NAD+
At the end of the citric acid cycle, most of the energy remaining from the original glucose is stored in
NADH
During electron transport, energy from _____ is used to pump hydrogen ions into the _____.
NADH and FADH2 ... inter-membrane space
A small amount of ATP is made in glycolysis _____.
by the transfer of a phosphate group from a fragment of glucose to ADP (substrate-level phosphorylation)
By-products of cellular respiration include
carbon dioxide and water
Most NADH molecules generated during cellular respiration are produced during __________.
citric acid cycle
What process occurs in Box B?
citric acid cycle
During cellular respiration, NADH
delivers its electron load to the first electron carrier molecule.
The transfer of ______ from one molecule to another is an oxidation-reduction reaction, or redox reaction.
electrons
Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________.
four; 3 NADH and 1 FADH2
What process occurs in Box A?
glycolysis
We inhale O2 and we exhale CO2. Carbon dioxide is produced __________.
in the reaction that creates acetyl CoA (coenzyme A) from pyruvate
During cellular respiration, energy in glucose
is carried by electrons
In cellular respiration, most ATP molecules are produced by _____.
oxidative phosphorylation
In cellular respiration, glucose becomes ____ to carbon dioxide (CO2) as it loses electrons (in hydrogen atoms).
oxidized
NADH delivers electrons to an electron transport chain, which passes the electrons through carrier molecules in a series of redox reactions to the final electron acceptor. ____
oxygen
In cellular respiration, oxygen becomes ______ to water (H2O) as it gains electrons (in hydrogen atoms) that came from glucose.
reduced
Glycolysis is the only stage of cellular respiration that __________.
requires ATP to make ATP
In glycolysis, ATP molecules are produced by _____.
substrate-level phosphorylation
Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____.
these two stages supply the electrons needed for the electron transport chain
NADH and FADH 2 are important in cellular respiration because they deliver high-energy electrons to the electron transport system. Electron transport produces _____ ATP molecule(s) per NADH molecule and _____ ATP molecules(s) perFADH 2 molecule.
three ... two
In electron transport, high-energy electrons "fall" to oxygen through a series of reactions. The energy released is used to _____.
transport protons into the inter-membrane space of the mitochondria, where they become concentrated. They then flow back out into the the inner compartment (matrix) of the mitochondria. On the way back, protons turn ATP synthase turbines and produce ATP.
How many NADH are produced by glycolysis?
two
In glycolysis there is a net gain of _____ ATP.
two
The energy production per acetyl CoA molecule through the citric acid cycle is __________.
1 ATP, 3 NADH, 1 FADH2
Cellular respiration completely breaks down a glucose molecule through glycolysis and the citric acid cycle. However, these two processes yield only a few ATPs. The majority of the energy the cell derives from glucose is _____.
found in NADH and FADH2
