Period 4 11/17/16
Energy, Enzymes, and Metabolism Chapter 8: Vocabulary Vocabulary
Definition
1) Enzyme
A catalytic protein that speeds up biochemical reactions
2) Energy
The capacity to work or to create change
3) Metabolism
The total of all chemical reactions carried out by an organism
4) Catalyst
A chemical agent that speeds up a reaction without being consumed by the reaction
5) Coenzymes
Organic Cofactor (i.e. vitamins)
6) Cofactors
Nonprotein helpers bound permanently to the enzyme or loosely and reversibly along with the substrate that many enzymes require for catalytic activity
Picture
7) Exergonic Reaction
A reaction that proceeds with a net release of free energy (Change in G is negative, is spontaneous)
8) Endergonic Reaction
A reaction that absorbs free energy from its surroundings (Change in G is positive, not spontaneous)
9) Activation Energy
The initial investment of energy for starting a reaction, the energy required to contort the reactant molecules so the bonds can change; same as free energy of activation
10) Substrate
The reactant an enzyme acts on
11) Active site
A pocket or groove on an enzyme and the region the substrate binds to. The active site changes its shape slightly as the substrate enters the active site to create an induced fit
12) Induced fit model
Brings chemical groups of the active site into positions that enhance their ability to catalyze the chemical reaction
13) Competitive inhibition
Mimics of the substrate that reduce productivity of enzymes by blocking substrates from entering active sites. Can be overcome by increasing the concentration of the substrate
14) Noncompetitive inhibition
Inhibitors that impede enzyme activity by binding to another part of the enzyme and causing the enzyme to change its shape
15) Allosteric inhibition
Any case in which a protein's function at one site is affected by the binding of a regulatory molecule to a separate site, may inhibit or stimulate enzyme activity
16) Cooperativity
The mechanism that amplifies the response of enzymes to substrates; one substrate molecule primes an enzyme to accept additional substrate molecules more readily
17)Enzyme-substrate complex
A complex formed when an enzyme binds to its substrate(s); When they're joined, the catalytic action of the enzyme converts the substrate(s) to the product(s)
18) Adenosine Triphosphate (ATP)
A nucleic acid consisting of ribose, nitrogenous base adenine, and chain of three phosphate groups; Hydrolysis of the phosphate bonds releases energy
19) Anabolic reactions
Pathway that consumes energy to build complex molecules from simpler ones
20) Catabolic reactions
Pathway that releases energy by breaking down complex molecules into simpler ones
21) Free energy (G)
Measures the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system
22) First law of thermodynamics
The energy of the universe is constant, energy can be transferred and transferred but not created or destroyed (Principle of conservation of energy)
23) Second law of thermodynamics
Every energy transfer or transformation increases the entropy of the universe