Chapter 8 Flashcards
First Law of Thermodynamics
energy can neither be created nor destroyed. It may change from one form to another, but the energy in a closed system remains constant.
Entropy
Measure of disorder in a closed system.
Second Law of Thermodynamics
when energy is transferred, there will be less energy available at the end of the transfer process than at the beginning.
Define Metabolism
The chemical reactions that occur in cells that are responsible for actions of organisms.
Define Metabolites
The chemicals that take part in metabolism’s chemical reactions.
Exergonic Reactions
Energy is released to the surroundings as the reaction forms new bonds. The bonds being formed are
stronger than the bonds being broken. Energy Level is lower than the start of the reaction.
Endergonic Reaction
Energy is absorbed from the surroundings. The bonds being formed are
weaker than the bonds being broken. Energy Level is higher than the start of the reaction.
What occurs in all chemical reactions?
chemical bonds in the reacting molecules are broken; this takes in energy
then,
new chemical bonds form to make the products; this gives out energy.
The final energy level determines whether the reaction was exergonic or endergonic.
Anabolic Reactions
Anabolic reactions use up energy. They are endergonic. In an anabolic reaction small molecules join
to make larger ones.
Catabolic Reactions
Catabolic reactions give out energy. They are exergonic. In a catabolic reaction large molecules are
broken down into smaller ones.
Kinetic Energy
Energy at work, being used. Bowling Ball moving down a ramp.
Potential Energy
Stored Energy, Energy not actively in use. Bowling Ball at the top of a ramp.
Activated Complexes
The substance formed in the middle of a chemical reaction, between reactant and product. Cannot be obtained/viewed. Always results in an endergonic reaction.
Activation Energy
The amount of energy required to bring molecules together in the correction orientation in the formation of an Activated Complex.
Reaction Intermediate
The material formed in between steps of a chemical reaction.
How can you determine if a reaction is spontaneous?
If the ΔG is negative.
What is an ATP molecule made up of?
3 Phosphate groups
1 Ribose Sugar
1 Adenine
What causes which bond to break in ATP
Hydrolysis will break the bond between the last and the middle phosphate groups.
Is energy released or absorbed when the terminal phosphate bond is broken?
Energy is released
ATP when broken forms which two molecules?
ADP and Pi
Define Energy Coupling.
Energy coupling is a critical concept in cellular biology that refers to the linkage of energy-releasing reactions (exergonic
reactions) to energy-consuming reactions (endergonic reactions) within a cell. This process ensures that the energy
released from one reaction is immediately used to drive another reaction that requires energy input, thus maintaining
efficiency and continuity in metabolic processes.
What is the function of enzymes?
They are catalysts that increase the rate of a chemical reaction by lowering the activation energy, the energy required to start a reaction.
What are substrates?
A biological molecule that an enzyme works on.
What is an active site?
A specially shaped area of an enzyme that fits around a substrate.
What is catalysis
When a substrate is changed in an enzyme’s active site, either broken down or combined with another molecule to create something new.
What is a product?
It is what the substrate turns into after catalysis with an enzyme.
What is Denaturing
When a control changes an enzymes shape. Can be caused by temperature, activators, pH levels and inhibitors.
Activators
Materials that cause enzymes to work harder and faster. They can help the enzyme bind to the substrate.
Inhibitors
Something that slows down or stops the activity of an enzyme. Competitive inhibitors block the active site and Allosteric Inhibitors bond to another spot, changing the shape of the enzyme.
Feedback
A situation when the output or response of a loop impacts or influences the input or stimulus.
Positive Feedback loops
When an increase of something leads to the increased production of it.
Negative Feedback loops
When an increased in something leads to a decreased production of it.
What is a cofactor
A non-protein chemical compound that is bound to a protein and is required for the protein’s biological activity. The proteins are commonly enzymes.
What is a coenzyme
An organic molecule that binds to the active sites of certain enzymes to assist in the catalysis of the reaction.
What is cooperatively
A phenomenon in which the shape of one subunit of an enzyme consisting of several subunits is altered by the substrate, or some other molecule as to change the shape of a neighboring subunit.
Allosteric Regulation
A widespread mechanism of control protein function.
