T01 - Introduction to Metabolism Flashcards
Metabolism consists of what two primary energy processes?
catabolism; anabolism
Catabolism is primary responsible for
energy production
Anabolism is primarily responsible for
the synthesis of macromolecules
Draw a diagram that illustrates the consumption and regeneration of electron carriers in catabolism and anabolism.
What are the two factors that determine energy need requirements?
basal energy expenditure (BEE)
body mass index (BMI)
What is the First Law of Thermodynamics?
energy can neither be created nor destroyed, but can be converted from one form to another
Draw an energy diagram that shows the stepwise oxidation of sugar in cells.
Draw an energy diagram that shows the direct burning of sugar in cells.
Write out the chemical reaction showing hydrolysis of ATP into ADP and Pi. What is the ΔG°’ of this reaction?
ATP + H2O → ADP + Pi
ΔG°’ = -7.3 kcal/mol
Write out the chemical reaction showing hydrolysis of ATP into AMP and PPi. What is the ΔG°’ of this reaction?
ATP + H2O → AMP + PPi
ΔG°’ = -10.9 kcal/mol
Describe the energy “composition” of a typical 70 kg man.
1,600 kcal in glycogen
24,000 kcal in mobilizable protein
135,000 kcal in fat
What molecule is, by far, the largest fuel source in mammals?
fat
What is the metabolic energy equivalent for carbohydrates?
4 kcal/g
What is the metabolic energy equivalent for protein?
4 kcal/g
What is the metabolic energy equivalent for fat?
9 kcal/g
What molecule serves as the primary carbohydrate/metabolic fuel in mammals?
glucose
Outline the path of glucose as a metabolic fuel. (7)
glucose → [glycolysis] → pyruvate → acetyl-CoA → [TCA coupled to reduction of NAD+ and FAD to NADH and FADH2] → [electron transport chain] → [ox phos] → ~36 ATP
Give two major (alternative) energy sources in mammal (other than glucose).
fatty acids
amino acids
Outline the pathway of fatty acids as a metabolic fuel. (2)
palmitate → [complete oxidation] → ~129 ATP
Outline the two pathways of amino acids as a metabolic fuel.
AA → [transaminase] → keto-acid → [feed into TCA or glycolysis]
AA → [feed into gluconeogenesis]
What two hormones are the primary regulators of metabolism?
insulin and glucagon
Insulin promotes
storage of simple monomeric fuels in polymeric form
Glucagon promotes
oxidation of polymeric storage depots to yield monomeric units for fuel
Describe the relative activities of insulin and glucagon in anabolism.
insulin activity increased
glucagon activity decreased
Describe the relative activities of insulin and glucagon in catabolism.
insulin activity decreased
glucagon activity increased
What is fuel source in anabolism?
diet
What is fuel source in catabolism?
storage depots
Basal energy expenditure results from what two actions?
heat production
keeping the brain alive
Write out the equation to calculate BMI.
What are the BMI intervals and their associated weight statuses?
below 18.5 = underweight
- 5 - 24.9 = normal
- 0 - 29.9 = overweight
>30.0 = obese
Rank carbohydrates, amino acids, and fats in terms of ease of metabolism.
carbohydrates > amino acids > fats
What are the symptoms of metabolic syndrome? (4)
increased blood pressure
high blood glucose
body fat around the wait
abnormal cholesterol or triglyceride levels
What are the risk factors for metabolic syndrome? (3)
age
race
obesity
What is the pathology of metabolic syndrome?
diabetes
cardiovascular disease
Rank methane, methanol, formaldehyde, formic acid, and carbon dioxide in terms of ΔG°, going from most negative to least negative.
more C-H bonds in small molecules = more energy
oxidation of methane is most favorable (most negative ΔG° value)
What are the high-energy bonds within ATP?
the bond between alpha and beta, and the bond between beta and gamma
the bond between the ribose and alpha phosphate is low energy
The conversion of ATP to ADP is associated with what processes? (4)
motion
active transport
biosyntheses
signal amplification
The conversion of ADP to ATP is associated with what processes?
oxidation of fuel molecules
photosynthesis
Describe how ATP is used to drive unfavorable reactions, using glutamic acid as an example.
phosphate transferred from ATP to glutamic acid to form high-energy intermediate
phosphate (Pi) released and NH3 added to form glutamine
therefore, products of ATP hydrolysis are ADP and Pi
Draw a diagram that shows the relationship between NADP+, NADPH, catabolism, and anabolism.
Glycolysis occurs in what cellular structure?
cytosol
Insulin is produced by
the beta cells of pancreatic islets
Glucagon is synthesized by
alpha cells of the pancreas
