Chapter 8
For every glucose molecule entering respiration, ____ ATP are produced
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What are the products of glycolysis?
4 ATP, 2 pyruvate, 2 NADH
Which stage of respiration is anaerobic?
glycolysis
_____ joins with acetyl-CoA to form citric acid in the Krebs cycle
oxaloacetic acid
As high-energy electrons are passed from carrier to carrier along the electron transport system in cellular respiration, the electrons lose energy. Some of that energy is directly used to __________.
pump hydrogen ions across a membrane
ATP consists of a ____ sugar, a ____ base and three phosphates
ribose, nitrogenous
Where does the Krebs cycle occur?
the mitochondrion
During which chemical reactions is ATP made during glycolysis?
1,3-bisphosphate to 3-phosphoglycerate & 2-phosphoenolpyruvate(PEP) to pyruvate
What are the three stages of cellular respiration?
1.) glycolysis 2.) Krebs cycle 3.) Electron transport chain
What do you have to put into glycolysis to get the products?
2 ATP
(Per 2 pyruvate entering) what are the products of the Krebs cycle?
2 ATP, 10 NADH, 2FADH2
The ETC produces ____ ATP
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What chemical pathway extracts energy from sugars?
Glycolysis and cellular respiration
Suppose that the reactions of mitochondria of a green plant were completely inhibited. What process would immediately be reduced?
If the reactions of mitochondria of a green plant were completely inhibited ATP production would be immediately reduced. The end product of glycolysis is further broken down during cellular respiration in mitochondria, supplying far greater amounts of energy in ATP.
Which molecules are produced in glycolysis and used in fermentation?
Pyruvate and NADH
In eukaryotic cells, pyruvate produced by glycolysis is transported into the mitochondrial matrix, where __________.
cytoplasm; mitochondria
Where does the electron transport chain of cellular respiration take place?
the cristae (folds) of the mitochondrion
Where does glycolysis take place?
the cytoplasm
Photosynthesis and glucose metabolism are related because __________.
the products of photosynthesis are the raw materials for glucose metabolism, and the products of glucose metabolism are the raw materials for photosynthesis
______ allows protons to cross membranes during the ETC, providing the energy needed to phosphorylate ADP into ATP
ATP synthase
What is the net yield of ATP from glycolysis?
2ATP
Each NADH molecule from the Krebs cycle produces ___ ATP
3
What is the net gain of ATP molecules that can be produced from the breakdown of glucose?
36
What is the role of coenzyme A (CoA) in cellular respiration?
A carrier molecule for an acetyl group
____ is how we derive energy from the food we eat
Cellular respiration
Where are the six CO2 molecules created that were derived from glucose?
During the conversions of pyruvate to an acetyl group, isocitrate to alpha-ketoglutarate, and to alpha-ketoglutarate to succinate
Why is it necessary to invest two ATP molecules during the first stage of Glycolysis?
Energy from ATP is used to break a six carbon sugar into two three carbon ones.
In aerobic organisms growing in the presence of oxygen, the NADH produced by glycolysis ultimately donates its high-energy electrons to __________.
In aerobic organisms growing in the presence of oxygen, the NADH produced by glycolysis ultimately donates its high-energy electrons to electron transport chains in the mitochondria.
In eukaryotes, during the process of chemiosmosis, ATP is produced as hydrogen ions move from __________ to __________, passing through __________.
In eukaryotes, during the process of chemiosmosis, ATP is produced as hydrogen ions move from the intermembrane compartment to the matrix, passing through an ATP synthase. The hydrogen ions flow down their concentration gradient from the intermembrane space and into the matrix through ATP synthase channels, generating ATP from ADP and phosphate.
What is the role of NAD+ in glycolysis
NAD+ molecules accept high energy electrons and carry for energy extraction.
What products of the Krebs cycle feed the electron transport chain?
NADH and FADH2
What is the net gain of ATP from Glycolysis?
The net gain of ATP from Glycolysis is 2. During glycolysis, two ATP are generated from each G3P, for a total of four ATP per glucose molecule. Because two ATP were used up to form fructose bisphosphate, there is a net gain of only two ATP per glucose molecule.
In cellular respiration, the final electron acceptor is ____
an oxygen atom
In eukaryotic cells, the enzymes for the Krebs cycle are located in the __________, and those for the electron transport system are located in the __________.
mitochondrial matrix; inner mitochondrial membrane
When glucose goes through glycolysis and all the way through the Krebs cycle, what is the fate of the six carbon molecules of glucose?
they become carbon dioxide
How much ATP does a person produce and regenerate every day?
Approximately equivalent to their body weight.
The overall equation for glucose metabolism is C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP and heat. The carbon atoms in the CO2 molecules in this equation come from __________ during reactions of __________.
C6H12O6; the Krebs cycle
What is the product of the fermentation of sugar by yeast in bread dough that is essential for the rising of the dough?
CO2
What are the by-products of cellular respiration?
6CO2 + 6H2O + energy
What goes into cellular respiration?
C6H12O6 + 6O2
How is most of the energy extracted from the molecules going through the Krebs Cycle?
Through high energy electrons attaching to NAD+ and FAD
How do cells recycle NADH back to NAD+ during fermentation?
by converting pyruvate to lactic acid or to ethanol and carbon dioxide.
Glycolysis can be broken down into what two parts?
energy-investing and energy-harvesting
Which pathway produces the most ATP per glucose molecule?
Cellular respiration results in 32 ATP made from a molecule of glucose. Fermentation makes no ATP itself, but allows glycolysis to continue, which has a net gain of two ATP. The Krebs cycle makes one ATP each time it cycles, which is twice for each original molecule of glucose, so it makes two ATPs.
How do we create fat for storage?
During the conversions of pyruvate to an acetyl group, isocitrate to alpha-ketoglutarate, and to alpha-ketoglutarate to succinate
If glucose provides the major source of energy burned through glycolysis and cellular respiration, how do we use fats as an energy source?
Fatty acids combine with Coenzyme A to form many Acetyl-CoA compounds.
How many ATP are produced each time the Kreb cycle works?
One ATP is produced each time the Kreb cycle works.
What is the final fate of oxygen that is breathed in during respiration and used in cellular respiration?
Oxygen is converted to H2O ( One water molecule is produced for every two electrons that traverse the ETC.)
What role is played by the electron transport chain during cellular respiration?
The electron transport system takes energy from the high-energy electrons brought by electron carriers (NADH) and uses it to pump hydrogen ions against their concentration gradients from the matrix into the intermembrane compartment.
The energy-harvesting reactions of glycolysis produce four molecules of __________, two molecules of __________, and two molecules of __________.
The energy-harvesting reactions of glycolysis produce four molecules of ATP, two molecules of NADH, and two molecules of pyruvate. During the energy harvesting stage, the two G3P molecules are converted into two molecules of pyruvate, generating a total of four ATP molecules and two NADH molecules. Glycolysis has a net energy yield of two ATP molecules and two NADH molecules.
The overall equation for glucose metabolism is C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP and heat. The carbon atoms in the CO2 molecules in this equation come from __________ during reactions of __________
The overall equation for glucose metabolism is C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP and heat. The carbon atoms in the CO2 molecules in this equation come from C6H12O6 during reactions of the Krebs cycle. The Krebs cycle breaks down the two pyruvate molecules (produced from glucose during glycolysis) into six carbon dioxide molecules and six water molecules.
The production of what molecule marks the end of glycolysis and the beginning of cellular respiration?
The production of pyruvate marks the end of glycolysis and the beginning of cellular respiration. Pyruvate, the end product of glycolysis, is synthesized in the cytosol. Before cellular respiration can occur, the pyruvate is actively transported from the cytosol into the mitochondrial matrix, where cellular respiration begins.
In eukaryotic cells, pyruvate produced by glycolysis is transported into the mitochondrial matrix, where __________.
enzymes for the Krebs cycle break down the pyruvate, producing CO2 as a waste product
What is chemiosmosis?
it is the process by which energy is used to generate a concentration gradient of H+
