Metabolism Flashcards
Catabolic pathways
Oxidize complex molecules, generating smaller molecule. Release energy in process
Anabolic pathways
Synthesize complex molecules from smaller molecules and require energy input
What are the two metabolic pathways?
Catabolic and Anabolic
What are the major macronutrients?
Fat
Carbohydrate
Protein
What is the fed state?
Your diet
What is included in the fasting state?
Carbohydrate released from glycogen deposits and synthesized from amino acids
Fat released from triacylglyceride stores
Protein from catabolism of muscle protein, releasing free amino acids
What is the acceptable macronutrient distribution range for carbs?
45%-65%
How many calories in 1 g of carbohydrates?
4 kcal
What are digestible carbs and what do they degrade to?
Mostly starch and degraded to glucose, which is needed by red blood cells, brain, and many tissues
What is the acceptable macronutrient distribution range for fat?
20%-35%
How many calories in 1g of fat?
9 kcal - energy dense
What is the major fat source, what does it degrade to, and what is it important for?
Triacylglycerols
Degraded to fatty acids that are important energy source for skeletal and cardiac muscle, used by liver, but NOT the brain
What is the acceptable macronutrient distribution range of protein?
10%-35%
How many calories in 1g of protein?
4 kcal
What is protein degraded to and where is it abosorbed?
Amino acids.
Absorbed by various tissues for protein synthehsis and oxidation of energy
Partial oxidation occurs in the liver when used for gluconeogenesis or lipogenesis
What is the “other” source of calories?
Alcohol. Produces 7 kcal per 1g of ethanol.
What is the driving net force of a reaction?
Gibbs free energy change
What does it mean when Gibbs free energy change is negative?
Spontaneous reaction. Products have less free energy than reactants
What does Gibbs Free Energy equal at equilibrium?
0
Does Gibbs Free Energy tells us about rate of a reaction?
no!!!
What are standard conditions for free energy change? What does it allow?
concentration of reactant and product = 1M
Pressure of 1 atm
Temperature of 25 degrees Celsius
pH of 7
Change in Gibbs Free Energy is constant
*Allows reactions to be compared under identical conditions
What does Gibbs free energy change rely on?
Depends on relative concentration of products and reactants
How does metabolism relate to Gibbs Free Energy change?
Products often removed during metabolism which changes the concentration of products and then changes gibbs free energy change
Reaction coupling. What is the overall free energy change?
Two reactions can be coupled together if they share common intermediates. Overall free energy change for a couples series is equal to the sum of the free energy changes of the individual steps.
