Chapter 6 & 7
In cellular respiration, glucose is oxidized when it ___________electrons in hydrogen atoms, and oxygen is reduced as it ____________ electrons in hydrogen atoms.
loses , gains
A molecule that functions as the electron donor in a redox reaction __________.
loses electrons and becomes oxidized
Most ATP in eukaryotic cells is produced in the:
mitochondria
Each glucose molecule yields __________ molecule(s) of ATP during the citric acid cycle.
2
The net result of the breakdown of glucose in glycolysis and fermentation is the production of:
2 ATP
Each turn of the citric acid cycle generates one ATP molecule as well as which energy-rich molecules?
3 NADH and 1 FADH2
About how much ATP is produced by the metabolism of one molecule of glucose in cellular respiration?
32 molecules This is the number of molecules of ATP that are produced by glycolysis, the citric acid cycle, and oxidative phosphorylation.
In aerobic respiration, the energy in 1 mole of glucose is capable of producing how many ATP molecules:
38 x (6.02 x 1023) molecules of ATP
A person's basal metabolic rate (BMR) is equal to about __________.
1,300-1,500 Calories/day
Given the relatively modest number of calories burned by any but the most vigorous activities, why can most people consume more than 2,000 kilocalories per day yet maintain a healthy body weight?
A large proportion of the energy consumed in food is needed to maintain the body's functions, so only a fraction of food energy needs to be burned in exercise.
In glycolysis, the activation of glucose is accomplished by:
ATP
As protons flow through the ______, energy is released and exploited to combine ADP and inorganic phosphate to form ATP.
ATP synthase
Which of the following statements about glycolysis is correct?
ATP to make ATP
In aerobic respiration carbohydrates are ultimately broken down into:
CO2
Cellular respiration is a series of chemical reactions that harvest energy in the form of ATP from glucose and other organic molecules. What else is released?
CO2 and water are also released.
Which of the following statements regarding the reduction of CO2 to sugar during photosynthesis is correct?
Electrons (with accompanying protons) from water are transferred to CO2 during photosynthesis.
Why are wine barrels and beer fermentation vats designed to keep air out?
Facultative anaerobes prefer aerobic pathways.
Which of the following statements about glycolysis is INCORRECT?
Glycolysis became a universal cellular process about the time that significant levels of O2 appeared in the atmosphere. (Glycolysis is anaerobic and, hence, did not require oxygen.)
What is the role of the dehydrogenase enzyme at the beginning of the electron transport chain in cellular respiration?
It transfers two electrons from the glucose molecule to NAD+, reducing it to NADH.
Which stage of aerobic respiration produces ATP and NADH and releases CO2?
Krebs cycle
During fermentation, __________ that was produced during glycolysis is converted back to __________.
NADH; NAD+
The light reactions of photosynthesis yield __________. The Calvin cycle produces __________.
O2, ATP, NADPH; sugar, ADP, NADP+
Scientists used isotopes to identify the source of oxygen released during photosynthesis. What did they discover?
The O2 comes from water, not CO2
Applying/Analyzing 6.10 Evidence suggests that heat-generating brown fat is most active in __________.
babies and lean people exposed to cold temperatures
Oxidation and reduction always go together, as electron transfer requires
both a donor and an acceptor.
Let's look at the big picture here: Fueled by the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle, such as pyruvate and acetyl CoA, are siphoned off and used to __________.
build proteins, fats, and carbohydrates
Products of the Krebs cycle include:
carbon dioxide, NADH, FADH2
Most ATP produced in aerobic respiration occurs in the process of:
chemiosmosis
The reduction of NADP+ to NADPH in the light reactions occurs with the assistance of __________.
electrons from water and energy from sunlight
What process regulates the rate of cellular respiration?
feedback inhibition
In the presence of oxygen, all cells synthesize ATP via the process of glycolysis. Many cells also can metabolize pyruvate if oxygen is not present, via the process of:
fermentation
Which stage of aerobic respiration requires ATP?
glycolysis
Sunlight is essential for the varied life on Earth because it provides __________.
he energy necessary to power the rearrangement of chemical bonds in H2O and CO2 (conversion of water and carbon dioxide to sugars.)
At what point in cellular respiration is the first molecule of CO2 produced?
in the reaction that creates acetyl CoA (coenzyme A) from pyruvate
Several _________________ are formed in a series of redox reactions, each of which is catalyzed by a different enzyme.
intermediates
Which of the following are photoautotrophs?
kelp, a large sea alga
Which stage of aerobic respiration requires CO2?
none of the above (glycolysis, Krebs cycle, electron transport chain, fermentation)
Glycolysis begins with __________ and ends with __________.
one molecule of glucose, two molecules of pyruvate
An electron "donor" donates (loses) electrons, thereby becoming __________________
oxidized
The final electron acceptor in aerobic respiration is:
oxygen
The high concentration of protons in the inner mitochondrial space relative to the mitochondrial matrix represents:
potential energy
What is the most important function of carotenoid pigments in plants?
protect cells from excess sunlight
In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to __________.
pump protons (H+) across the mitochondrial membrane
In glycolysis the most reduced compound formed is:
pyruvate
Products of glycolysis include:
pyruvate, ATP, and NADH
Which of the following organelles can open or close? Thylakoids are found in the __________ of the chloroplast.
stomata; stroma
What "powers" ATP synthase, allowing it to catalyze the conversion of ADP to ATP in the presence of phosphate?
the flow of H+ ions down their concentration gradient.
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.
Which of the following is the role of cellular respiration?
to harvest energy from organic molecules
Fat is the most efficient fuel molecule because __________.
with their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons
