AP Bio 3.6 Cellular Respiration Glycolysis Krebs ETC
36 flashcards covering AP Bio 3.6 Cellular Respiration Glycolysis Krebs ETC for the AP-BIOLOGY Unit 3 section.
Cellular respiration is a critical biological process that encompasses glycolysis, the Krebs cycle, and the electron transport chain (ETC). According to the College Board's AP Biology Curriculum Framework, this topic is essential for understanding how cells convert glucose into usable energy in the form of ATP. Each phase of cellular respiration plays a unique role in energy production and is interconnected, making it vital for students to grasp these concepts thoroughly.
On practice exams, questions related to cellular respiration often require students to explain the steps and outcomes of each phase, analyze diagrams, or apply their knowledge to specific scenarios. A common pitfall is misunderstanding the role of oxygen in the ETC, leading to confusion about aerobic versus anaerobic processes. Students may also misinterpret the energy yield from glycolysis compared to the Krebs cycle, which can affect their overall understanding of cellular efficiency.
Remember, a practical tip is to focus on the significance of ATP yield in different conditions, as this often comes up in real-world applications and assessments.
Terms (36)
- 01
What is glycolysis?
Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing a net gain of two ATP molecules and two NADH molecules. It occurs in the cytoplasm of the cell (College Board AP CED).
- 02
How many ATP molecules are produced in glycolysis?
Glycolysis produces a net gain of two ATP molecules per glucose molecule. This process also generates two NADH molecules (College Board AP CED).
- 03
What is the primary purpose of the Krebs cycle?
The primary purpose of the Krebs cycle is to oxidize acetyl-CoA to produce NADH and FADH2, which are used in the electron transport chain to generate ATP (College Board AP CED).
- 04
Where does the Krebs cycle occur in eukaryotic cells?
The Krebs cycle occurs in the mitochondrial matrix of eukaryotic cells (College Board AP CED).
- 05
What is the main product of the Krebs cycle?
The main products of the Krebs cycle include NADH, FADH2, ATP (or GTP), and carbon dioxide as a waste product (College Board AP CED).
- 06
How many NADH molecules are produced per turn of the Krebs cycle?
Three NADH molecules are produced per turn of the Krebs cycle (College Board AP CED).
- 07
What role do NADH and FADH2 play in cellular respiration?
NADH and FADH2 serve as electron carriers that donate electrons to the electron transport chain, leading to ATP production (College Board AP CED).
- 08
What is the electron transport chain?
The electron transport chain is a series of protein complexes located in the inner mitochondrial membrane that transfer electrons from NADH and FADH2 to oxygen, creating a proton gradient for ATP synthesis (College Board AP CED).
- 09
What is oxidative phosphorylation?
Oxidative phosphorylation is the process by which ATP is produced using the energy released from the electron transport chain and the proton gradient generated across the inner mitochondrial membrane (College Board AP CED).
- 10
What is the final electron acceptor in the electron transport chain?
The final electron acceptor in the electron transport chain is oxygen, which combines with electrons and protons to form water (College Board AP CED).
- 11
What is fermentation, and when does it occur?
Fermentation is an anaerobic process that occurs when oxygen is not available, allowing cells to regenerate NAD+ from NADH to continue glycolysis (College Board AP CED).
- 12
What are the two types of fermentation?
The two types of fermentation are alcoholic fermentation and lactic acid fermentation. Alcoholic fermentation produces ethanol and carbon dioxide, while lactic acid fermentation produces lactic acid (College Board AP CED).
- 13
How many ATP are produced during aerobic respiration from one glucose molecule?
A total of approximately 30 to 32 ATP molecules can be produced from one glucose molecule during aerobic respiration, depending on the efficiency of the electron transport chain (College Board AP CED).
- 14
What is substrate-level phosphorylation?
Substrate-level phosphorylation is the direct transfer of a phosphate group to ADP from a phosphorylated intermediate, occurring in glycolysis and the Krebs cycle (College Board AP CED).
- 15
What is the role of coenzyme A in cellular respiration?
Coenzyme A is involved in the transport of acetyl groups into the Krebs cycle, where it combines with oxaloacetate to form citrate (College Board AP CED).
- 16
What is chemiosmosis?
Chemiosmosis is the movement of protons across a membrane, driving the synthesis of ATP via ATP synthase during oxidative phosphorylation (College Board AP CED).
- 17
What is the purpose of the proton gradient in the electron transport chain?
The proton gradient created by the electron transport chain is used to drive ATP synthesis as protons flow back into the mitochondrial matrix through ATP synthase (College Board AP CED).
- 18
What happens to pyruvate before it enters the Krebs cycle?
Before entering the Krebs cycle, pyruvate is converted into acetyl-CoA by the enzyme pyruvate dehydrogenase, releasing carbon dioxide and producing NADH (College Board AP CED).
- 19
What is the role of oxygen in cellular respiration?
Oxygen acts as the final electron acceptor in the electron transport chain, allowing for the continuation of aerobic respiration and preventing the backup of electrons (College Board AP CED).
- 20
What is the significance of the citric acid cycle?
The citric acid cycle, or Krebs cycle, is significant as it generates high-energy electron carriers (NADH and FADH2) and ATP, which are essential for energy production in aerobic respiration (College Board AP CED).
- 21
What is the difference between aerobic and anaerobic respiration?
Aerobic respiration requires oxygen and produces significantly more ATP than anaerobic respiration, which occurs without oxygen and results in less ATP production (College Board AP CED).
- 22
What is the role of ATP synthase?
ATP synthase is an enzyme that synthesizes ATP from ADP and inorganic phosphate, using the energy from the proton gradient established by the electron transport chain (College Board AP CED).
- 23
What are the end products of glycolysis?
The end products of glycolysis are two pyruvate molecules, two ATP molecules (net), and two NADH molecules (College Board AP CED).
- 24
How does lactic acid fermentation differ from alcoholic fermentation?
Lactic acid fermentation produces lactic acid and occurs in muscle cells, while alcoholic fermentation produces ethanol and carbon dioxide and occurs in yeast (College Board AP CED).
- 25
What is the role of FAD in cellular respiration?
FAD acts as an electron carrier similar to NAD+, accepting electrons during the Krebs cycle to form FADH2, which then donates electrons to the electron transport chain (College Board AP CED).
- 26
What is the function of the inner mitochondrial membrane?
The inner mitochondrial membrane houses the electron transport chain and ATP synthase, facilitating ATP production through oxidative phosphorylation (College Board AP CED).
- 27
What is the importance of the Krebs cycle in metabolism?
The Krebs cycle is crucial for metabolizing carbohydrates, fats, and proteins, providing intermediates for biosynthesis and energy production (College Board AP CED).
- 28
What is the role of NAD+ in glycolysis?
NAD+ serves as an electron acceptor in glycolysis, being reduced to NADH, which is essential for the continuation of the glycolytic pathway (College Board AP CED).
- 29
What occurs during the transition reaction between glycolysis and the Krebs cycle?
During the transition reaction, pyruvate is decarboxylated, producing acetyl-CoA and releasing carbon dioxide, while also generating NADH (College Board AP CED).
- 30
How does the electron transport chain generate a proton gradient?
The electron transport chain generates a proton gradient by pumping protons from the mitochondrial matrix into the intermembrane space as electrons are transferred through the complexes (College Board AP CED).
- 31
What is the effect of cyanide on cellular respiration?
Cyanide inhibits cytochrome c oxidase in the electron transport chain, preventing electron transfer to oxygen and halting ATP production (College Board AP CED).
- 32
What is the role of oxygen in the Krebs cycle?
Oxygen is not directly involved in the Krebs cycle; however, it is essential for the electron transport chain, which relies on the products of the Krebs cycle (College Board AP CED).
- 33
What is the significance of carbon dioxide production in cellular respiration?
Carbon dioxide is a byproduct of the Krebs cycle and is significant as it indicates the complete oxidation of glucose during cellular respiration (College Board AP CED).
- 34
What is the role of glycolysis in both aerobic and anaerobic respiration?
Glycolysis is the first step in both aerobic and anaerobic respiration, breaking down glucose into pyruvate, regardless of oxygen availability (College Board AP CED).
- 35
How does ATP yield differ between aerobic and anaerobic respiration?
Aerobic respiration yields approximately 30-32 ATP per glucose molecule, while anaerobic respiration yields only 2 ATP from glycolysis (College Board AP CED).
- 36
What is the significance of the electron transport chain in energy production?
The electron transport chain is significant as it produces the majority of ATP during cellular respiration through oxidative phosphorylation and the establishment of a proton gradient (College Board AP CED).