BackMetabolism and Energy Regulation: Anatomy & Physiology Study Guidance
Study Guide - Smart Notes
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Q1. Within a living cell, the oxidation of one molecule is always coupled with the simultaneous _________ of another molecule.
Background
Topic: Redox Reactions in Cellular Metabolism
This question tests your understanding of oxidation-reduction (redox) reactions, which are fundamental to energy transfer in cells.
Key Terms and Concepts:
Oxidation: Loss of electrons from a molecule.
Reduction: Gain of electrons by a molecule.
Redox reactions always occur in pairs: when one molecule is oxidized, another is reduced.
Step-by-Step Guidance
Recall that in metabolism, energy is transferred via electrons.
When a molecule loses electrons (is oxidized), those electrons must be accepted by another molecule.
Think about what process is the opposite of oxidation in these reactions.
Fill in the blank with the term that describes the gain of electrons.
Try solving on your own before revealing the answer!
Final Answer: reduction
In redox reactions, oxidation is always coupled with reduction. When one molecule is oxidized, another is reduced by accepting the electrons.
Q2. In the transitional step between glycolysis and the Krebs cycle, _____________________ occurs.
Background
Topic: Cellular Respiration Pathways
This question focuses on the metabolic step that links glycolysis to the Krebs (citric acid) cycle.
Key Terms and Concepts:
Glycolysis: The breakdown of glucose to pyruvate in the cytoplasm.
Krebs Cycle: A series of reactions in the mitochondria that further oxidize products of glycolysis.
The transitional step involves converting pyruvate into a molecule that can enter the Krebs cycle.
Step-by-Step Guidance
Recall what happens to pyruvate after glycolysis, before it enters the Krebs cycle.
Think about the name of the process that removes a carbon from pyruvate and forms a two-carbon molecule.
Consider what molecule is produced that can combine with coenzyme A.
Fill in the blank with the name of this process or the product formed.
Try solving on your own before revealing the answer!
Final Answer: formation of acetyl-CoA (pyruvate decarboxylation)
Pyruvate is converted to acetyl-CoA in the mitochondria, releasing CO2 and producing NADH. This is known as the transitional or link reaction.
Q3. Essential amino acids are those that ______________________
Background
Topic: Protein and Amino Acid Metabolism
This question tests your knowledge of the difference between essential and non-essential amino acids.
Key Terms:
Essential amino acids: Amino acids that cannot be synthesized by the body and must be obtained from the diet.
Non-essential amino acids: Amino acids that the body can synthesize.
Step-by-Step Guidance
Recall the definition of essential nutrients in general.
Think about whether the body can make these amino acids or if they must come from food.
Fill in the blank with a phrase that describes their dietary requirement.
Try solving on your own before revealing the answer!
Final Answer: must be obtained from the diet (cannot be synthesized by the body)
Essential amino acids are those that the human body cannot synthesize in sufficient amounts, so they must be supplied by the diet.
Q4. In fatty acid metabolism, which molecule enters the Krebs cycle? ___________________
Background
Topic: Lipid Metabolism
This question is about how fatty acids are broken down and what product of this process enters the Krebs cycle.
Key Terms and Concepts:
Beta-oxidation: The process by which fatty acids are broken down in the mitochondria.
Krebs cycle: The cycle that oxidizes acetyl groups to CO2 and generates NADH and FADH2.
Consider what molecule is produced from beta-oxidation that can enter the Krebs cycle.
Step-by-Step Guidance
Recall the process that breaks down fatty acids into two-carbon units.
Think about the name of the two-carbon molecule produced by beta-oxidation.
Identify which molecule combines with oxaloacetate to enter the Krebs cycle.
Try solving on your own before revealing the answer!
Final Answer: acetyl-CoA
Fatty acids are broken down by beta-oxidation to form acetyl-CoA, which then enters the Krebs cycle.
Q5. A nutrient: (define) _________________________________
Background
Topic: Nutrition and Metabolism
This question asks for the definition of a nutrient in the context of human physiology.
Key Terms:
Nutrient: A substance that provides nourishment essential for growth and the maintenance of life.
Step-by-Step Guidance
Think about what substances are required by the body for energy, growth, and maintenance.
Consider both macronutrients (carbohydrates, proteins, fats) and micronutrients (vitamins, minerals).
Formulate a concise definition that includes these aspects.
Try solving on your own before revealing the answer!
Final Answer: a substance in food that provides energy, promotes growth, and regulates body processes
A nutrient is any chemical substance that an organism needs to sustain life, including energy, growth, and regulation of bodily functions.
Q6. Which hormone stimulates Gluconeogenesis? __________________
Background
Topic: Hormonal Regulation of Metabolism
This question tests your knowledge of hormones that regulate glucose production in the liver.
Key Terms:
Gluconeogenesis: The process of synthesizing glucose from non-carbohydrate sources.
Consider hormones that increase blood glucose levels, especially during fasting.
Step-by-Step Guidance
Recall which hormones are released during low blood sugar or fasting states.
Think about which hormone specifically promotes the formation of new glucose in the liver.
Fill in the blank with the hormone's name.
Try solving on your own before revealing the answer!
Final Answer: glucagon
Glucagon stimulates gluconeogenesis in the liver, increasing blood glucose levels during fasting.
Q7. The electron transport chain is a stepwise release of energy for the generation of ___________________.
Background
Topic: Cellular Respiration – Electron Transport Chain
This question is about the main product generated by the electron transport chain in mitochondria.
Key Terms and Concepts:
Electron Transport Chain (ETC): A series of protein complexes in the inner mitochondrial membrane.
The ETC uses electrons from NADH and FADH2 to create a proton gradient.
This gradient is used to synthesize a key energy molecule.
Step-by-Step Guidance
Recall what molecule is the main energy currency of the cell.
Think about how the ETC uses the proton gradient to drive the synthesis of this molecule.
Fill in the blank with the name of the molecule produced.
Try solving on your own before revealing the answer!
Final Answer: ATP (adenosine triphosphate)
The electron transport chain generates ATP by oxidative phosphorylation, using the energy from electrons transferred through the chain.
Q8. Body temperature is ultimately regulated by the _____________.
Background
Topic: Thermoregulation
This question tests your knowledge of the body's temperature control center.
Key Terms:
Thermoregulation: The process of maintaining core body temperature.
Consider which part of the brain acts as the body's thermostat.
Step-by-Step Guidance
Recall which brain structure monitors blood temperature and initiates responses to heat or cold.
Think about the name of the region in the diencephalon responsible for homeostasis.
Fill in the blank with the correct anatomical term.
Try solving on your own before revealing the answer!
Final Answer: hypothalamus
The hypothalamus acts as the body's thermostat, regulating core temperature through various mechanisms.
Q9. The energy for metabolism is primarily transferred by molecules for the purpose of ____________________.
Background
Topic: Energy Transfer in Cells
This question is about the role of energy-carrying molecules in metabolism.
Key Terms:
ATP: The main energy currency of the cell.
Energy is transferred to perform cellular work, such as muscle contraction, active transport, and biosynthesis.
Step-by-Step Guidance
Think about what cells use energy for at the molecular level.
Consider the types of work that require energy input in the cell.
Fill in the blank with a phrase describing the main purpose of energy transfer.
Try solving on your own before revealing the answer!
Final Answer: cellular work (such as synthesis, movement, and transport)
Energy is transferred by molecules like ATP to power cellular processes, including biosynthesis, movement, and active transport.
Q10. Which of the following are minerals that function as coenzymes? _________________
Background
Topic: Vitamins, Minerals, and Enzyme Function
This question asks you to identify minerals that act as cofactors or coenzymes in metabolic reactions.
Key Terms:
Coenzyme: An organic molecule or mineral that assists enzymes in catalyzing reactions.
Some minerals serve as cofactors, which are essential for enzyme activity.
Step-by-Step Guidance
Recall which minerals are commonly required for enzyme function (e.g., magnesium, zinc, iron).
Think about examples of minerals that are essential for metabolic pathways.
List at least two minerals that serve this role.
Try solving on your own before revealing the answer!
Final Answer: magnesium, zinc, iron, copper, selenium
These minerals act as cofactors for various enzymes, enabling metabolic reactions to proceed.
Q11. The function of HDL’s is to : __________________________________________
Background
Topic: Lipoproteins and Cholesterol Transport
This question is about the role of high-density lipoproteins (HDL) in the body.
Key Terms:
HDL (High-Density Lipoprotein): Known as "good cholesterol" because of its beneficial effects.
HDL is involved in cholesterol transport and removal from tissues.
Step-by-Step Guidance
Recall the main function of HDL in lipid metabolism.
Think about whether HDL delivers cholesterol to tissues or removes it.
Fill in the blank with a phrase describing HDL's role in cholesterol transport.
Try solving on your own before revealing the answer!
Final Answer: transport cholesterol from tissues to the liver for excretion
HDL removes excess cholesterol from peripheral tissues and carries it to the liver for disposal, reducing the risk of atherosclerosis.
Q12. Vit. D deficiency causes: _____________________________
Background
Topic: Vitamins and Deficiency Diseases
This question tests your knowledge of the consequences of vitamin D deficiency.
Key Terms:
Vitamin D: Essential for calcium absorption and bone health.
Deficiency leads to bone disorders.
Step-by-Step Guidance
Recall the role of vitamin D in calcium metabolism and bone formation.
Think about the diseases associated with poor bone mineralization.
Fill in the blank with the name of the condition(s) caused by deficiency.
Try solving on your own before revealing the answer!
Final Answer: rickets (in children) and osteomalacia (in adults)
Vitamin D deficiency impairs calcium absorption, leading to soft, weak bones (rickets in children, osteomalacia in adults).
Q13. Each gram of fat yields about _____ kcal.
Background
Topic: Energy Content of Nutrients
This question is about the caloric value of macronutrients, specifically fats.
Key Terms:
Calorie (kcal): A unit of energy.
Fats provide more energy per gram than carbohydrates or proteins.
Step-by-Step Guidance
Recall the standard energy values for macronutrients: carbohydrates, proteins, and fats.
Think about which macronutrient provides the most energy per gram.
Fill in the blank with the correct number of kilocalories per gram of fat.
Try solving on your own before revealing the answer!
Final Answer: 9 kcal
Each gram of fat yields about 9 kilocalories, which is more than carbohydrates (4 kcal/g) or proteins (4 kcal/g).
Q14. The hunger and satiety centers for the regulation of food intake are located in the ________________.
Background
Topic: Regulation of Appetite
This question is about the brain region responsible for controlling hunger and fullness.
Key Terms:
Satiety center: Area that signals fullness.
Hunger center: Area that signals the need to eat.
Both are located in a specific part of the brain.
Step-by-Step Guidance
Recall which brain structure is involved in homeostatic regulation, including appetite.
Think about the same structure that regulates body temperature and other autonomic functions.
Fill in the blank with the correct anatomical term.
Try solving on your own before revealing the answer!
Final Answer: hypothalamus
The hypothalamus contains the centers that regulate hunger and satiety.
Q15. An example of anabolism is the ________________________________.
Background
Topic: Metabolic Pathways – Anabolism vs. Catabolism
This question asks for an example of a biosynthetic (anabolic) process.
Key Terms:
Anabolism: The synthesis of complex molecules from simpler ones, requiring energy.
Examples include protein synthesis, glycogen synthesis, and DNA replication.
Step-by-Step Guidance
Recall the definition of anabolism and think of processes that build up molecules.
Consider examples such as the formation of proteins from amino acids or glycogen from glucose.
Fill in the blank with a specific anabolic process.
Try solving on your own before revealing the answer!
Final Answer: synthesis of proteins from amino acids
Protein synthesis is a classic example of an anabolic process, building complex molecules from simpler ones.
Q16. The amount of energy from food transferred to ATP and available for cellular functions equals about ______%
Background
Topic: Energy Efficiency in Metabolism
This question is about the efficiency of energy transfer from food to usable ATP.
Key Terms:
Not all energy from food is captured as ATP; some is lost as heat.
Only a certain percentage is available for cellular work.
Step-by-Step Guidance
Recall the approximate efficiency of cellular respiration in converting food energy to ATP.
Think about the percentage of energy lost as heat versus captured as ATP.
Fill in the blank with the correct percentage.
Try solving on your own before revealing the answer!
Final Answer: 40%
About 40% of the energy from food is transferred to ATP; the rest is lost as heat.
Q17. The major regulator of BMR is _______________.
Background
Topic: Basal Metabolic Rate (BMR) Regulation
This question is about the main factor controlling the body's resting energy expenditure.
Key Terms:
BMR (Basal Metabolic Rate): The rate at which the body uses energy at rest.
Hormones, especially from the thyroid gland, play a key role.
Step-by-Step Guidance
Recall which hormones increase metabolic rate in most tissues.
Think about the gland that produces these hormones.
Fill in the blank with the hormone or gland responsible.
Try solving on your own before revealing the answer!
Final Answer: thyroid hormones (especially thyroxine)
Thyroid hormones are the primary regulators of BMR, increasing the rate of energy expenditure in cells.
Q18. Too high a core body temperature can be fatal because it causes __________________.
Background
Topic: Effects of Hyperthermia
This question is about the dangers of elevated body temperature.
Key Terms:
Hyperthermia: Abnormally high body temperature.
High temperatures can disrupt protein structure and function.
Step-by-Step Guidance
Recall what happens to enzymes and proteins at high temperatures.
Think about the term for the loss of protein structure and function.
Fill in the blank with the process that leads to cell and organ failure.
Try solving on your own before revealing the answer!
Final Answer: denaturation of proteins (and enzyme inactivation)
High core body temperature can denature proteins, leading to loss of enzyme function and potentially fatal organ failure.
Q19. In a negative feedback mechanism of body temperature regulation, in response to a decrease of body temperature, the hypothalamus releases _________________.
Background
Topic: Thermoregulation and Feedback Mechanisms
This question is about how the hypothalamus responds to cold to restore normal body temperature.
Key Terms:
Negative feedback: A control mechanism that opposes changes from a set point.
In response to cold, the body initiates heat-generating mechanisms.
Step-by-Step Guidance
Recall what hormones or signals are released to increase heat production.
Think about the role of the hypothalamus in stimulating the thyroid and adrenal glands.
Fill in the blank with the hormone or signal released.
Try solving on your own before revealing the answer!
Final Answer: thyrotropin-releasing hormone (TRH)
The hypothalamus releases TRH, which stimulates the pituitary to release TSH, increasing thyroid hormone production and metabolic heat.
Q20. When you touch a cool object, you lose heat by ______________.
Background
Topic: Mechanisms of Heat Transfer
This question is about the physical process by which heat is transferred from the body to a cooler object.
Key Terms:
Conduction: Direct transfer of heat between objects in contact.
Other mechanisms include convection, radiation, and evaporation.
Step-by-Step Guidance
Recall the four main mechanisms of heat loss from the body.
Think about which mechanism involves direct contact with another object.
Fill in the blank with the correct term.
Try solving on your own before revealing the answer!
Final Answer: conduction
Heat is lost by conduction when the body is in direct contact with a cooler object.
Q21. When, as a result of pyrogens, the body thermostat is set to a higher temperature, you will experience __________.
Background
Topic: Fever and Pyrogens
This question is about the physiological response to fever-inducing substances (pyrogens).
Key Terms:
Pyrogens: Substances that cause fever by raising the hypothalamic set point.
When the set point increases, the body responds to reach the new temperature.
Step-by-Step Guidance
Recall what happens when the hypothalamic set point is raised.
Think about the symptoms experienced as the body tries to reach the new set point.
Fill in the blank with the term for this experience.
Try solving on your own before revealing the answer!
Final Answer: chills (shivering)
When the set point is raised, you feel cold and shiver as the body generates heat to reach the new temperature.
Q22. A coupled chemical reaction that directly transfers a high energy phosphate group from a substrate to ADP, producing ATP is called ______________________________.
Background
Topic: ATP Synthesis Mechanisms
This question is about the process of ATP formation during glycolysis and the Krebs cycle.
Key Terms:
Substrate-level phosphorylation: Direct transfer of a phosphate group to ADP from a phosphorylated substrate.
Contrast with oxidative phosphorylation, which uses the electron transport chain.
Step-by-Step Guidance
Recall the two main ways ATP is generated in cells.
Think about which process occurs directly in glycolysis and the Krebs cycle.
Fill in the blank with the correct term.
Try solving on your own before revealing the answer!
Final Answer: substrate-level phosphorylation
This process directly transfers a phosphate group from a substrate to ADP, forming ATP.
Q23. As a result of glycolysis, there is a net gain of _______ ATP molecules?
Background
Topic: Glycolysis – Energy Yield
This question is about the net ATP produced during glycolysis from one molecule of glucose.
Key Terms and Formula:
Glycolysis: The breakdown of glucose to pyruvate, producing ATP and NADH.
ATP is both consumed and produced during glycolysis.
Step-by-Step Guidance
Recall how many ATP molecules are used in the early steps of glycolysis.
Recall how many ATP molecules are produced in the later steps.
Subtract the ATP used from the ATP produced to find the net gain.
Try solving on your own before revealing the answer!
Final Answer: 2 ATP
Glycolysis produces 4 ATP but uses 2 ATP, resulting in a net gain of 2 ATP per glucose molecule.
Q24. For every glucose molecule metabolized, how many CO2 molecules are produced?
Background
Topic: Cellular Respiration – Carbon Dioxide Production
This question is about the total CO2 generated from complete aerobic metabolism of one glucose molecule.
Key Terms and Formula:
Glycolysis: No CO2 produced.
Pyruvate decarboxylation: Each pyruvate produces 1 CO2 (2 per glucose).
Krebs cycle: Each acetyl-CoA produces 2 CO2 (4 per glucose).
Step-by-Step Guidance
Calculate the number of CO2 molecules produced during the conversion of pyruvate to acetyl-CoA.
Calculate the number of CO2 molecules produced during the Krebs cycle.
Add the totals to find the overall number of CO2 molecules per glucose.
Try solving on your own before revealing the answer!
Final Answer: 6 CO2 molecules
Each glucose yields 2 pyruvate (2 CO2 from decarboxylation) and 4 CO2 from the Krebs cycle, totaling 6 CO2.
Q25. In which cellular component does glycolysis occur? ______________
Background
Topic: Cellular Compartmentalization of Metabolic Pathways
This question is about the location of glycolysis within the cell.
Key Terms:
Glycolysis: The breakdown of glucose to pyruvate.
Occurs in a specific part of the cell, not in the mitochondria.
Step-by-Step Guidance
Recall the difference between cytoplasm and mitochondria in terms of metabolic pathways.
Think about where glycolysis takes place before pyruvate enters the mitochondria.
Fill in the blank with the correct cellular location.
Try solving on your own before revealing the answer!
Final Answer: cytoplasm (cytosol)
Glycolysis occurs in the cytoplasm of the cell.
Q26. The majority of fat in the body is stored in fat cells located ________________
Background
Topic: Lipid Storage
This question is about the anatomical location of fat storage in the body.
Key Terms:
Adipose tissue: Specialized connective tissue for fat storage.
Fat cells are called adipocytes.
Step-by-Step Guidance
Recall the name of the tissue where fat is stored.
Think about the distribution of this tissue in the body.
Fill in the blank with the correct anatomical term.
Try solving on your own before revealing the answer!
Final Answer: in adipose tissue (subcutaneous and visceral fat)
Most body fat is stored in adipose tissue, especially under the skin and around internal organs.
Q27. Acetone, acetoacetic acid and beta-hydroxybutyric acid are: ______________.
Background
Topic: Ketone Bodies and Ketosis
This question is about the products of fatty acid metabolism during fasting or diabetes.
Key Terms:
Ketone bodies: Water-soluble molecules produced in the liver from fatty acids.
Formed during periods of low carbohydrate availability.
Step-by-Step Guidance
Recall the names of the three main ketone bodies.
Think about the metabolic state in which they are produced.
Fill in the blank with the collective term for these molecules.
Try solving on your own before revealing the answer!
Final Answer: ketone bodies
Acetone, acetoacetic acid, and beta-hydroxybutyric acid are the three main ketone bodies.
Q28. An increase in urea in the blood would indicate an increase in the breakdown of ____________.
Background
Topic: Protein Metabolism and Nitrogen Excretion
This question is about the metabolic process that leads to increased urea production.
Key Terms:
Urea: The main nitrogenous waste product in urine.
Formed from the breakdown of amino acids.
Step-by-Step Guidance
Recall what macronutrient contains nitrogen in its structure.
Think about what happens to amino acids during catabolism.
Fill in the blank with the correct macronutrient.
Try solving on your own before revealing the answer!
Final Answer: proteins (amino acids)
Increased urea indicates increased protein breakdown, as amino groups are converted to urea in the liver.
Q29. Before amino acids can enter the Krebs cycle, they must undergo ____________.
Background
Topic: Amino Acid Catabolism
This question is about the process that removes the amino group from amino acids before they can be used for energy.
Key Terms:
Deamination: Removal of the amino group from amino acids.
This process produces ammonia, which is converted to urea.
Step-by-Step Guidance
Recall what must be removed from amino acids before they can be used in the Krebs cycle.
Think about the name of the process that removes the amino group.
Fill in the blank with the correct term.
Try solving on your own before revealing the answer!
Final Answer: deamination
Amino acids must be deaminated before their carbon skeletons can enter the Krebs cycle.
Q30. What structure is formed immediately after glucose enters the cell? _______________
Background
Topic: Glycolysis – First Step
This question is about the first chemical change that happens to glucose inside the cell.
Key Terms and Formula:
Glucose phosphorylation: The addition of a phosphate group to glucose.
The product is a phosphorylated glucose molecule.
Step-by-Step Guidance
Recall the enzyme that acts on glucose as soon as it enters the cell.
Think about the name of the product formed after phosphorylation.
Fill in the blank with the correct chemical name.
Try solving on your own before revealing the answer!
Final Answer: glucose-6-phosphate
Glucose is immediately phosphorylated to glucose-6-phosphate upon entering the cell.
Q31. Which structure will undergo different reactions, depending on whether oxygen is plentiful, or in short supply? ____________.
Background
Topic: Aerobic vs. Anaerobic Metabolism
This question is about the metabolic fate of a key glycolytic intermediate under different oxygen conditions.
Key Terms:
Pyruvate: The end product of glycolysis.
In the presence of oxygen, pyruvate enters the mitochondria; without oxygen, it is converted to lactate.
Step-by-Step Guidance
Recall the fate of pyruvate under aerobic and anaerobic conditions.
Think about which molecule is the branching point for these pathways.
Fill in the blank with the correct structure.
Try solving on your own before revealing the answer!
Final Answer: pyruvate
Pyruvate can be converted to acetyl-CoA (aerobic) or lactate (anaerobic), depending on oxygen availability.
Q32. The main hormones that are active in the absorptive state are: __________ _________
Background
Topic: Hormonal Regulation of Nutrient Storage
This question is about the hormones that promote nutrient storage after eating.
Key Terms:
Absorptive state: The period after a meal when nutrients are being absorbed and stored.
Insulin is the main hormone; others may also play a role.
Step-by-Step Guidance
Recall which hormone is released in response to high blood glucose.
Think about any other hormones that may be active during this state.
Fill in the blanks with the main hormone(s).
Try solving on your own before revealing the answer!
Final Answer: insulin (and to a lesser extent, growth hormone)
Insulin is the primary hormone active in the absorptive state, promoting glucose uptake and storage.
Q33. During the absorptive state, amino acids are used by most cells for ______________.
Background
Topic: Protein Synthesis in the Absorptive State
This question is about the fate of amino acids after a meal.
Key Terms:
Absorptive state: Period of nutrient absorption and storage.
Amino acids are primarily used for building proteins.
Step-by-Step Guidance
Recall the main anabolic process involving amino acids after eating.
Think about the role of amino acids in cell growth and repair.
Fill in the blank with the main use of amino acids in this state.
Try solving on your own before revealing the answer!
Final Answer: protein synthesis
During the absorptive state, amino acids are mainly used for synthesizing new proteins.
Q34. During the postabsorptive state, when we exercise, the anaerobically produced lactic acid is carried to the liver for ____________________________________________.
Background
Topic: Cori Cycle and Lactic Acid Metabolism
This question is about the fate of lactic acid produced during anaerobic exercise.
Key Terms:
Lactic acid: Produced by anaerobic glycolysis in muscles.
Cori cycle: The process by which lactic acid is converted back to glucose in the liver.
Step-by-Step Guidance
Recall what happens to lactic acid after it is produced in muscles.
Think about the metabolic pathway in the liver that converts lactic acid to another molecule.
Fill in the blank with the name of this process or its result.
Try solving on your own before revealing the answer!
Final Answer: conversion to glucose (gluconeogenesis)
Lactic acid is transported to the liver, where it is converted back to glucose via the Cori cycle.
Q35. Which of the series in the cellular respiration processes uses oxygen in the last reaction of the series? ____________.
Background
Topic: Cellular Respiration – Oxygen Utilization
This question is about the stage of cellular respiration where oxygen acts as the final electron acceptor.
Key Terms:
Electron Transport Chain (ETC): The final stage of aerobic respiration.
Oxygen is required to accept electrons and form water.
Step-by-Step Guidance
Recall the three main stages of cellular respiration: glycolysis, Krebs cycle, and electron transport chain.
Think about which stage directly uses oxygen as a reactant.
Fill in the blank with the correct stage.
Try solving on your own before revealing the answer!
Final Answer: electron transport chain
The electron transport chain uses oxygen as the final electron acceptor, forming water in the last step.
