Cellular Respiration Khan Academy Q
Which of the following occur during the Krebs cycle?
-NAD+ is reduced to form NADH. -Acetyl-CoA combines with oxaloacetate to form citrate.
What is the net production of ATP, pyruvate, and NADH when one molecule of glucose undergoes glycolysis?
2 ATP, 2 NADH, 2 pyruvate
ATP is an important biological molecule that transports chemical energy within cells and powers many biochemical reactions.
ATP contains a 5-carbon sugar, three phosphate groups, and an adenine base. Energy is released when the bond between the second phosphate group and third phosphate group is broken.
Which product of pyruvate oxidation enters the Krebs cycle?
Acetyl-CoA
Which of the following is true of electron carriers NADH and FADH2?
All of the electrons that enter the transport chain (ETC) come from NADH and FADH2 molecules which are produced during earlier phases of cellular respiration.
What equations accurately represents cellular respiration?
C6H12O6 (glucose) +6O2 (oxygen) ⟶6CO2 (carbon dioxide) +6H2O (water) + energy
What is the main transformation that occurs during glycolysis?
Glycolysis produces ATP, pyruvate, and NADH by oxidizing glucose.
During step 3 of the Krebs cycle, the enzyme isocitrate dehydrogenase (IDH) catalyzes the conversion of isocitrate to \alphaαalpha-ketoglutarate. IDH is allosterically activated by ADP at high concentrations. Which of the following best describes how this interaction helps regulate the Krebs cycle?
High levels of ADP stimulate the Krebs cycle, leading to the increased conversion of ADP to ATP during oxidative phosphorylation.
Dinitrophenol (DNP) is a chemical that acts as an uncoupling agent, making the inner mitochondrial membrane leaky to protons. It was used until 1938 as a weight-loss drug. How would DNP affect the amount of ATP produced in cellular respiration? Why do you think it is now off the market?*
It would decrease ATP production, but could also cause dangerously high body temperature
In what part of the cell does the Krebs cycle take place?
Mitochondria
What is true of NAD in cellular respiration?
NAD carries and transfers electrons and H+ ions.
In mitochondria, the rate of ATP synthesis during oxidative phosphorylation is tightly coupled to the movement of electrons through the electron transport chain (ETC). When ADP levels rise and the demand for ATP synthesis increases, electron flow through the ETC also increases. Based on the information above, which of the following best describes an effect of rising ADP levels in mitochondria?
Oxygen consumption will increase.
Unlike most other cells in the human body, mature red blood cells (RBCs) do not contain a nucleus or mitochondria. This allows RBCs to carry more hemoglobin, and therefore oxygen, through the bloodstream. Based on the information above, which of the following is most likely true about RBCs?
RBCs generate lactate as a waste product.
Identify each of the following molecules as reactants or products of the Krebs cycle.
Reactants: Acetyl CoA, NAD+, FAD Product: CO2, NADH, FADH2
Cellular respiration is a type of oxidation-reduction (redox) reaction. What is getting oxidized and reduced during cellular respiration?
The carbon atoms in glucose are oxidized, and oxygen is reduced. In cellular respiration, the carbon atoms in glucose are oxidized because they lose H atoms. Oxygen is reduced because it gains H atoms.
Cyanide acts as a poison because it inhibits complex IV, making it unable to transport electrons. How would cyanide poisoning affect 1) the electron transport chain and 2) the proton gradient across the inner mitochondrial membrane?
The electron transport chain would stop, and the gradient would decrease
Chemiosmosis is a part of oxidative phosphorylation, the final step in cellular respiration. Which of the following is true regarding chemiosmosis?
The energy from a proton gradient is used to make ATP.
The electron transport chain (ETC) is one part in oxidative phosphorylation, which is the last step in cellular respiration. Which of the following is true of the ETC?
The movement of electrons down the ETC drives the formation of a proton gradient.
Which of the following is true regarding the yield of ATP during aerobic cellular respiration?
The theoretical yield of ATP from aerobic cellular respiration is 38 ATP, but often times the actual yield is lower.
Which of the following statements about the Krebs cycle is most accurate?
not all living things engage in Krebs cycle
