Biology week 3
Week 3 Vocab for Bio 212 with Professor Mayfield.
Terms
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- Free energy
- The portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system.
- Exergonic reaction
- A spontaneous chemical reaction in which there is a net release of free energy.
- Endergonic reaction
- A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings.
- Catalyst
- A chemical agent that changes the rate of a reaction without being consumed by the reaction
- Enzyme
- A protein serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction
- Equilibrium constant
- A value that describes the relationship among the concentrations of the substances present in a system of equilibrium. The numerator is obtained by multiplying the concentrations of the substances on the product side of the equation, each raised to a power equal to its coefficient in the chemical equation. The denominator similarly contains the concentrations of the substances on the reactant side of the equation.
- Reactants
- Starting materials in a chemical reation.
- Products
- Ending materials in a chemical reaction.
- Intermediate
- In a coupled reaction, the compound that is both produced in the first reaction and is consumed in the second.
- Activation energy
- The amount of energy that reactants must absorb before a chemical reaction will start.
- Substrate
- The reactant on which an enzyme works.
- Competitive inhibition
- The process of a substance reducing the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.
- Allosteric enzyme
- of, relating to, or being a change in the shape and activity of a protein (as an enzyme) that results from combination with another substance at a point other than the chemically active site.
- Non-competitive inhibition
- The process of a substance reducing the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.
- Feedback inhibition
- A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.
- Catabolism
- The process of breaking down complex molecules to simpler compounds and releasing energy in the process.
- Anabolism
- The process that synthesizes a complex molecule from simpler compounds, thus requiring energy.
- Oxidation
- The loss of electrons from a substance involved in a redox reaction.
- Reduction
- The addition of electrons to a substance involved in a redox reaction.
- Redox
- A chemical reaction involving the transfer of one or more electrons from one reactant to another: also called oxidation-reduction reaction.
- Inner mitochondrial membrane
- The membrane of the mitochondria that is the site of electron transport and chemiosmosis.
- Outer mitochondrial membrane
- The outer membrane of the mitochondria.
- Matrix (mitochondria)
- The compartment of the mitochondria enclosed by the inner membrane and containing enzymes and substrates of the Kreb's Cycle.
- Cytosol
- The semi-fluid portion of the cytoplasm.
- Glycolysis
- The splitting of glucose into pyruvate. This is the one metabolic pathway that occurs in all living cells, serving as the starting point for fermentation or aerobic respiration.
- Glucose
- The "reactant" of glycolysis
- Pyruvate
- The end result of glycolysis.
- Coenzyme A (Co-A)
- A type of coenzyme that is an organic molecule serving as a cofactor. Most vitamins function as enzymes in important metabolic reactions.
- Kreb's Cycle
- A chemical cycle involving 8 steps that completes the metabolic breakdown of glucose molecules to carbon dioxide: occurs within the mitochondrian: the second major stage in cellular respiration (citric acid cycle.)
- Electron transport chain
- A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
- Hydrogen ion gradient
- During oxidation phosphorylation, hydrogen ions go down through an enzyme from higher concentration to lower concentration and across this, making ATP.
- Oxidation phosphorylation
- The production of ATP using energy derived from the redox reactions of an electron transport chain.
- ATP synthase
- A cluster of several membrane proteins found in the mitochondrial crista (and bacterial membrane) because that function in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion concentration gradient to make ATP. This provides a port through which hydrogen ions diffuse into the matrix of a mitochondrian.
- Product inhibition
- When too many products are formed in a reaction, the product attaches itself to an allosteric site on the enzyme and shuts down the enzyme. This helps maintain equilibrium.
- Competitive inhibition
- The process in which a different substrate goes into the active site of an enzyme, thus shutting down the enzyme and not allowing it to function
- Fermentation
- A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product.