Energy & Enzymes Flashcards
What is Energy? What are the 2 basic forms of energy?
Energy is the capacity to cause change (to change/rearrange matter)
- Kinetic: energy in motion
- Potential: static energy that can be converted to kinetic
What are the 2 primary laws of Thermodynamics? What is Entropy?
- Energy cannot be created or destroyed (it simply transforms into different states)
- Energy is “lost” (cannot be used) during conversion
- The energy that is “lost” can be describes as Entropy=> molecular disorder
T/F When energy is used, some portion is converted to a state that cannot be used by organisms.
True
What is Metabolism?
The total chemical reactions of an organism. (the conversion of matter from one state to the next)
T/F Each chemical reaction leaves slightly more energy in the products that follow.
How does it (gain/lose) slightly (more/less) energy?
False: Each reaction leaves slightly less energy in the products that follow.
Much of the energy that is lost is because of heat.
What are the 2 different pathways for Energetic Reactions? Explain them.
- Catabolic Pathways
Results in the release of energy via breaking down of molecules (Digestion) - Anabolic Pathways
Consume energy by building complex molecules from simpler molecules (Organisms growth & reproduction)
What is Free Energy (G)?
What is Delta G (∆G)?
Free Energy: the amount or the proportion of energy in a system that can be used to do work.
Delta G: the change in free energy.
What is the formula for Energetic Reactions within a system?
∆G= Gfinal - Ginitial
The change in free energy = Free energy at the end of a reaction - Free energy you start with
What happens if ∆G is negative?
What happens if ∆G is positive?
If ∆G is negative => Spontaneous reaction = more stable at the end => less energy available to do work
If ∆G is positive => Reaction requires energy input => less stable at the end => greater chance to do work
What are Exergonic & Endergonic Reactions?
Exergonic Reaction: net release of free energy=> negative ∆G
- Occur spontaneously
- The greater the ∆G the more energy released during the reaction
Endergonic Reaction: net storage of free energy=> positive ∆G
- Not spontaneous b/c reaction requires energy
What are Enzymes? How do they function?
Enzymes are macromolecules that speed up reactions. (catalyst)
- They are not consumed/broken down in reactions
- Most are proteins, some are RNA molecules
To speed up reactions enzymes lower the amount of energy that’s needed to get a particular reaction going. They lower the Activation Energy=> EA.
- Often in the form of heat energy
How and where do Enzymes lower the EA of reactions?
Bind reactants (substrates) to produce products
- The site where the reactants bind to an enzyme is called the Active Site.
Enzymes are highly specific to reactants
They help speed up reactions without increasing the heat energy.
- Too much heat can be bad (giant hornets)
What is Activation Energy EA?
EA is the minimum amount of extra energy required by a reaction molecule to get converted into a product.
Why is regulating enzymatic activity important for metabolism?
It’s important because it prevents certain reactions from continuing unchecked.
An organism may regulate its enzymatic activity through:
- Gene activation/deactivation
- Production of regulatory molecules (Allosteric Molecules)
- Feedback inhibition
