Metabolic Processes Flashcards
What is metabolism?
Metabolism refers to all of the chemical reactions that occur in a cell to transfer matter and energy. These reactions take place by step-by-step sequences called metabolic pathways where the product of one reaction becomes the reactant of the next reaction. Each of these reactions is catalyzed by an enzyme.
What two types of reactions play an important role in metabolism?
Metabolism= anabolism + catabolism
Metabolism represents the sum of all reactions in a living system/organism and consists of 2 processes that are constantly occurring simultaneously; catabolism and anabolism.
What is catabolism?
Catabolism is the process by which complex molecules are broken down into smaller, simpler molecules and stored energy is released.
examples: combustion/redox reactions
cellular respiration
What is anabolism?
Anabolism is the process by which complex molecules are synthesized from simpler ones. Requires energy input, energy is stored in the form of chemical bonds.
example: protein synthesis from amino acids
What 3 possibilities result from the interaction of anabolism+catabolism?
- When anabolism exceeds catabolism: growth or weight gain occurs, more energy is stored than released
- When catabolism exceeds anabolism: weight loss occurs, more energy is released than stored
- When catabolism and anabolism occur at the same rate a state of dynamic equilibrium occurs. Although the break down and building of molecules is still occuring, there is no net change.
What is the difference between kinetic and potential energy?
All forms of energy can be classified as kinetic or potential energy.
Kinetic Energy: energy possessed by moving objects (ex: heart muscles contracting), many forms of kinetic energy (includes thermal/heat/mechanical/electromagnetic energy)
Potential Energy: stored energy
(forms include gravitational/chemical/mechanical energy)
What is the 1st law of thermodynamics?
1st law of thermodynamics is aka the law of conservation of energy
Energy cannot be created or destroyed, but it can be converted from one form to another.
What is the 2nd law of thermodynamics?
When energy is transferred some energy becomes unusable and entropy increases. This increases the disorder of the universe.
What is the difference between entropy and free energy
Entropy= a measure of disorder (S)
Free Energy= ability to do work (Gibbs free energy (G))
**easier to create disorder than order: easy to increase S since energy is released (energy output, no energy input)
Gibbs free energy:
+G: endergonic change, non-spontaneous, cannot occur without energy input
-G: exergonic change, spontaneous, apart from activation energy requires no energy input, releases energy, energy output
What is an exothermic/exergonic reaction?
A chemical reaction that releases energy (forming bonds), energy output, spontaneous reaction, G<0, products have less energy than reactants, exergonic reactions
ex: combustion reaction
What is an endothermic/endergonic reaction
A chemical reaction that requires energy (breaking bonds), energy input, products have more energy than reactants, energy is absorbed, G>0, endergonic reactions
What determines the overall input or output of energy in a reaction?
The difference between input and output of energy.
What is an example of unusable energy?
Thermal energy/heat
What is energy coupling?
Energy coupling is when energy released from catabolic pathways is used to drive anabolic pathways.
