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Chapter 8-An Introduction to Metabolism - Coggle Diagram
Chapter 8-An Introduction to Metabolism
Thermodynamics
2nd law-The conversion of energy to thermal energy released as heat by living things
1st law-energy can be transferred or transformed but not created or destroyed
every energy transfer or transformation increases the entropy of the universe
metabolism
totality of an organism's chemical reactions
metabolic pathways
specific molecule is altered in a series of steps to produce a product
catabolic pathways
releases energy by breaking down complex molecules into simpler compounds (downhill)
example
cellular respiration
anabolic pathways
consume energy to build complex molecules from simpler ones (uphill)
Bioenergetics
study of how energy flows through living organisms
downhill reactions don't require much energy while uphill reactions require more energy
Enzyme inhibitors- certain chemicals selectively inhibit the action of specific enzymes
competitive inhibitors- closely resemble the substrate, can bind to the enzyme's active site
noncompetitive inhibitors- bind to another part of the enzyme, away from the active site
forms of energy
energy-the capacity to cause change, can be used to do work
kinetic energy
energy associated with motion
thermal energy
is the kinetic energy associated with random movement of atoms
heat is the thermal energy in transfer from one object to another
Potential energy
energy that matters possesses because of its location or structure; potential to do something or have motion
chemical energy
potential energy available for release in a chemical reaction
thermodynamics
study of energy transformations in a collection of matter
isolated systems-air tight/ no interaction with surrounding
open systems-energy and matter can be transferred between the system and its surrounding
spontaneous processes
occur when no additional energy is needed
free-energy change
free energy is the portion of a systems energy that can work when temperature and pressure are uniform throughout the system
ΔG=change in free energy, ΔH=change in enthalpy, ΔS=change in entropy, T=temperature in Kelvin (K); negative=spontaneous (less stable), positive=nonspontaneous, 0= equilibrium
catalyst- chemical agent that speeds up a reaction without being consumed by the reaction
enzyme- macromolecule (typically protein) that acts as a catalyst to speed up a specific reaction
The reactant of an enzyme is called a substrate, the enzyme binds to the substrate forming an enzyme-substrate complex. which then converts into a product
allosteric regulation- occurs when a regulatory molecule binds to a protein function at one site and affects the function at another site
cooperativity- substrate binding to one active site triggers shape change in the enzyme and stabilizes the active form for all other sites
ATP
Energy coupling- the use of an exergonic process to drive an endergonic
exergonic reaction (energy outward)- proceeds with a net release of free energy to the surroundings
endergonic reaction (energy inward)- absorbs free energy from the surroundings
composed of ribose (a sugar), adenine (a nitrogenous base), and three phosphate groups
Phosphorylation
transfer of a phosphate group from ATP to another molecule
phosphorylated intermediate is more reactive (less stable, with more free energy)
free energy needed to phosphorylate ADP comes from exergonic breakdown reactions (catabolism)