Bioenergetics, Enzymes And Metabolism Flashcards
Define Transduction
Transformation of energy from one form to another
Define Exothermic
Flow of energy from the systems surroundings (out put of energy)
Define Endothermic
Flow of energy from the systems surroundings (input of energy)
Define system
A sub component of the universe
What are the 2 laws of Thermodynamics?
1st Conservation-energy cannot be created or destroyed only changed
2nd Direction-events move towards states of lower energy and greater disorder (entropy)
What is free energy and what does it tell us?
The measure of energy available to do work
Tells us how much energy is needed, or released by the system
States that are _______ have high energy
Unstable
States that are are stable have ______ energy.
Low
How does Delta G work in a system?
Amount of energy in our system
Delta G=Gb-Ga
Where is the energy Gb and Ga located? (5)
- chemical bonds
- accumulated charges
- ordered system
- intrinsic energy
- measured in calories
Delta G can have 3 values what are they?
Positive
Negative
Zero
A negative Delta G means?
The system releases energy (exergonic)
The reaction is considered spontaneous/favorable
A positive Delta G tells us?
The system requires energy (endergonic)
The reaction is considered non-spontaneous/unfavorable
A Delta G at zero tells us?
The system is at equilibrium
What is coupling?
Ability of an enzyme to link an energy consuming reaction (endergonic) with an energy releasing reaction (exergonic) to allow a reaction to proceed.
What does any enzyme need? (4)
- active site
- substrate
- specificity
- catalytic power
What is an active site?
Binding site in which ligands go to be acted on
How do enzymes increase rates up to a million times?
By controlling the components of the chemical reactions
- stabalizing/inducing charges
- stressing/aligning substrates
- reduce the entropy of the system
What are the 3 types of inhibitors?
- Competitive
- Noncompetitive
- Irreversible
Tell me about competitive inhibition?
- inhibitor looks like a substrate and competes for the active site
- inhibitor cannot be catalyzed by the enzyme
What does competitive inhibition do to the values of Km and Vmax?
Km increases
Vmax does not change
What is Noncompetitive (Allosteric) inhibition?
- inhibitor does not look like substrate
- binds at a different site, not the active site
What do Noncompetitive inhibitors do to the values of Km and Vmax?
Km remains unchanged
Vmax drops
What happens in irreversible inhibition?
Binds very tightly often covalently, decreases all activity of the enzyme