47 Questions
What is the term used to describe the interconversion of chemical compounds in the body?
Metabolism
Which of the following is NOT a normal adaptation of metabolism?
Poisoning
What percentage of metabolic fuels comes from carbohydrates?
40-60%
Which of the following is an example of an anabolic pathway?
Synthesis of protein from amino acids
What is the relationship between anabolic pathways and energy?
Anabolic pathways are endothermic.
What is the third category of metabolic pathways mentioned in the text?
Amphibolic pathways
What is the primary fate of muscle glycogen breakdown?
Glucose-6-phosphate used to produce energy in the muscle
What is the primary fate of liver glycogen breakdown?
Glucose released into the circulation
What is the primary fate of triacylglycerol breakdown?
Fatty acids produced for oxidation in the mitochondria and glycerol used for gluconeogenesis
What is the primary fate of protein breakdown when glycogen stores are depleted?
Amino acids used for gluconeogenesis or directly catabolized in the TCA cycle
What is the common product that all digested products (glucose, fatty acids, glycerol, and amino acids) are metabolized to?
Acetyl-CoA
What is the primary energy source for erythrocytes (red blood cells)?
Glucose
What is the main characteristic of catabolic pathways?
They produce reducing equivalents
What is the primary function of amphibolic pathways in metabolism?
To act as links between anabolic and catabolic pathways
During the fed state, what molecules are oxidized for energy production?
Carbohydrates, lipids, and proteins
What happens in the body when the intake of metabolic fuels consistently exceeds energy expenditure?
Storage of surplus as triacylglycerol
Which hormone is dominant in the fasting state?
Glucagon
What does the citric acid cycle do within metabolism?
Acts as a link between anabolic and catabolic pathways
What is the process called when glucose is broken down in the cytoplasm to produce pyruvate?
Aerobic glycolysis
In which cellular process is lactate produced from glucose?
Anaerobic glycolysis
What is the process called when glucose is synthesized from non-carbohydrate precursors?
Gluconeogenesis
Which pathway produces NADPH for fatty acid synthesis?
Pentose phosphate pathway
What is the precursor for cholesterol and steroid synthesis?
Acetyl-CoA
Which metabolic process oxidizes acetyl-CoA to carbon dioxide and water?
Citric acid cycle
What is the main function of Adenylyl Kinase in cells?
Acting as a metabolic signal to increase catabolic reactions
How long does it take for creatine phosphate stores to be depleted during intense exercise?
30-50 seconds
What is the importance of Adenylyl Kinase for energy homeostasis in cells?
Enables the use of ADP in ATP synthesis
In the context of energy production, what role does Adenylyl Kinase play?
Increasing AMP concentration during ATP depletion
Which enzyme catalyzes the group transfer potential in ADP for ATP synthesis?
Adenylyl Kinase
What type of bond connects the phosphate groups in ATP?
Phosphodiester bond
Which of the following is a characteristic of the hydrolysis of ATP?
It is an exergonic reaction
Which of the following is NOT an example of a "high-energy compound" mentioned in the text?
Nicotinamide adenine dinucleotide (NAD)
Which of the following is a function of phosphagens?
To act as storage forms of group transfer potential (high energy phosphate)
Which of the following is an example of a phosphagen?
Creatine phosphate
What is the primary function of GTP in the context of the text?
To act as a substrate for substrate-level phosphorylation
If the free energy change (ΔG) of a reaction is positive, what does it indicate?
The reaction is endergonic and requires energy input to proceed
What is the term used for the breakdown or oxidation of fuel molecules, which are exergonic processes?
Catabolism
Which of the following statements about ATP is correct?
ATP is a nucleotide consisting of adenine, ribose, and three phosphate groups
What is the term used for the synthetic reactions that build up substances, which are endergonic processes?
Anabolism
If the free energy change (ΔG) of a reaction is zero, what does it indicate about the system?
The system is at equilibrium, and no net change occurs
What is the term used for the combined catabolic and anabolic processes in living organisms?
Metabolism
Which of the following statements about the first law of thermodynamics is correct?
The total energy of a system, including its surroundings, remains constant.
What is the relationship between entropy and a spontaneous process according to the second law of thermodynamics?
The total entropy of a system must increase for a process to occur spontaneously.
What is the significance of a negative value for the change in Gibbs free energy (ΔG) in a chemical reaction?
The reaction proceeds spontaneously with a loss of free energy, and is exergonic.
In an exothermic chemical reaction, what is the relationship between the enthalpy of the reactants and the enthalpy of the products?
The enthalpy of the reactants is greater than the enthalpy of the products.
What is the term used to describe reacting systems that take up heat from their surroundings?
Endothermic
What is the significance of a large negative value for the change in Gibbs free energy (ΔG) in a chemical reaction?
The reaction proceeds spontaneously and goes to completion, being essentially irreversible.
Learn about the interconversion of chemical compounds in the body, the pathways taken by individual molecules, their interrelationships, and the mechanisms that regulate the flow of metabolites through the pathways. Explore topics such as adaptation to fasting, starvation, exercise, pregnancy, and lactation in metabolism.
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