An Introduction To Metabolism Flashcards
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What is metabolism?
The totality if an organism’s chemical reactions
Definition of matabolic pathway
A series of connected chemical reactions that feed one another
Def of catabolic pathways
Involves the break down of complex molecules into simpler ones
Energy is released by breaking down complex molecules into simpler compounds
Cellular respiration definition
The breakdown of glucose in the presence of oxygen
This is an example of a pathway of Catabolism
What is kinetic energy?
Associated with motion
What is heat/thermal energy
Kinetic energy associated with random movement of atoms or molecules
Potential energy definition
Energy that matter possesses because of its location or structure
Chemical energy definition
Potential energy available for release in a chemical reaction
Additional
What is thermodynamics?
The study of energy transformations
What is the first law of thermodynamics?
Energy can be transferred and transformed but it cannot be created or destroyed
What does the 2nd law of thermodynamics state?
During every energy transfer or transformation some energy is unusable and is often lost as heat
What are spontaneous reactions?
They occur without energy input
Can occur quickly or slowly
For a process to occur without energy input, it must increase the entropy of the universe
Define the free energy of a living system
∆G
Energy that can do work when temperature and pressure are uniform( constant)
∆G=G (final state) - G (initial state)
What is another equation for ∆G?
∆G= ∆H - T×∆S
∆S= entropy
What is the change is free energy for spontaneous reactions?
Only processes with a negative ∆G are spontaneous
And/or
T∆S must be positive
Definition of Free Energy
A measure of a system’s instability
How does free energy change during a spontaneous change?
Free energy decreases and the stability of a system
When can a process perform work ?
When it moving toward equilibrium
What is an Exergonic Reaction in metabolism?
Proceeds with a net release of FREE ENERGY and is SPONTANEOUS.
What is an Endergonic reaction in metabolism?
Absorbs free energy from its surroundings and is non-spontaneous
What is a fact about reactions in a closed system?
Reactions in a closed system eventually reach equilibrium and the do not work
CELLS ARE NOT IN EQUILIBRIUM–THEY ARE OPEN SYSTEMS
Does metabolism ever reach Equilibrium?
No
What are the 3 kinds of work a cell does?
Chemical
Transport
Mechanical
How do cells do work?
They manage energy resources by energy coupling, the use of an exergonic process to drive an Endergonic one