Week 3 Flashcards
(47 cards)
Define Metabolism
the complete set of chemical reactions that can be performed in an organism. It is arranged as metabolic pathways, that can be intersecting, linear, etc.
What is catabolic and anabolic?
Catabolic is breakdown, while anabolic is build up.
What are the forms of energy?
Kinetic, thermal, potential, and chemical.
Define thermodynamics
the study of energy and its transformations
What is the difference between a system and surroundings?
A system refers to what is being studied, and the surroundings is everything else.
Define the first and second law of thermodynamics.
First: energy cannot be created or destroyed
Second: every energy transfer increases the entropy within the universe (disorder)
What is gibbs free energy? What is the equation.
It is the part of the system’s energy that can preform work.
G=H-T
What is Activation Energy
Energy required to start a chemical reaction, and determines the rate of a reaction. The more activation energy, the slower the reaction.
Transition state definition
molecules in an unstable condition, have enough energy to break and reform new bonds.
What are enzymes?
they are macromolecules that act as biological catalysts. Cells can contain large numbers of them, and we will focus on protein ones. Are found within specific organelles (ex. mitochondira).
Contains an active site where reactants of an enzyme bind.
Could require cofactors (inorganic) or coenzymes (organic).
What is a catalyst?
Speeds up a chemical reaction, but is not consumed during the reaction. Decreases the activation energy, without affecting gibbs free energy.
What is a substrate?
The reactant an enzyme acts on.
What is substrate speceficity?
Enzyme can only reckognize a certain number of substrates which is determined by the shape of the enzyme (active site)
What is the active site
Where the substrate binds and where the reaction occurs. Has a complementary size and charge for specefic substrates.
What is induced fit?
Changes in the active site to really “fit” the substrate once it has binded.
How can an enzymes activity be influenced?
Temperature and pH.
Explains why body temperature has to be highly regulated, or it can result in the denaturing of stuff, while blocks metabolism.
What is a multi-enzyme complex?
They carry out all of the steps of a metabolic pathway. Contains everything you need. If it was not organized like this, would slow down the metabolic processes that need to occur, makes this much more efficient.
What are the two types of inhibitors?
Competitive and non competitve inhibitors
Define competitive inhibitors
block the active site by directly binding to them.
Define non competitive inhibitors
interacts with an enzyme away from the active site, but changes the site of the active site in the process, meaning the substrate can no longer bind.
What is allosteric regulation?
it is the binding of a regulatory molecule to a protein at one site that affects the function at a different site.
It can activate or inhibit an enzyme.
Feedback inhibition is a type of allosteric regulation.
Define feedback inhibition
Where the regulatory molecule is the end product of the same metabolic pathway. This is a good way of controlling the concentration of a metabolite in the cell. Something would bind to the enzyme to change what is being produced, and whats produced is the regulatory molecule.
What are the three kinds of work that a cell does?
Chemical, transport, and mechanical
How is work accomplished within the cell? Explain.
Done through energy coupling.
The energy released from an exergonic reaction is used to power an endergonic one.
Generally mediated through ATP, as the energy generated from exergonic reactions is sued to synthesize ATP from ADP and inorganic molecules, and this releases energy that is used for cellular work, while also remaking ADP and phosphates.
