Bio 101 Exam 2

Chapter 6,7,8,9, and 10

activation energy 

energy necessary for reactions to occur

active site

enzyme's specific region to which the substrate binds

allosteric inhibition

The inhibitor binds somewhere other than the active site, changes the enzyme’s shape, and makes it harder for the substrate to bind.

anabolic 

pathways that require an energy input to synthesize complex molecules from simpler ones

ATP 

adenosine triphosphate, the cell’s energy currency

bioenergetics 

study of energy flowing through living systems

catabolic

pathways in which complex molecules break down into simpler ones

chemical energy 

potential energy in chemical bonds that releases when those bonds are broken

coenzyme

A small organic molecule, like a vitamin, that helps an enzyme work better.

cofactor

An inorganic ion, like iron or magnesium, that helps an enzyme work properly.

competitive inhibition 

A type of inhibition in which the inhibitor competes with the substrate for binding to the enzyme’s active site.

denature

process that changes a subtance's natural

properties, causing it to not function properly.

endergonic

describes chemical reactions that require energy input

enthalpy

a system's total energy

entropy (S) 

measure of randomness or disorder within a system

exergonic 

describes chemical reactions that release free energy

feedback inhibition

when the final product of a reaction pathway slows down its own production by inhibiting the first enzyme in the pathway.

Inhibit

to slow down, reduce, or stop an activity or process.

free energy 

Gibbs free energy is the usable energy, or energy that is available to do work

heat

energy transferred from one system to another that is not work (energy of the molecules' motion or particles)

heat energy 

total bond energy of reactants or products in a chemical reaction

induced fit 

when the enzyme and substrate change shape slightly so they fit together better

kinetic energy 

energy type that takes place with objects or particles in motion

metabolism

all the chemical reactions that take place inside cells, including anabolism and catabolism

phosphoanhydride bond 

bond that connects phosphates in an ATP molecule

potential energy 

energy type that has the potential to do work; stored energy

substrate 

the molecule that an enzyme acts on

thermodynamics

study of energy and energy transfer involving physical matter

transition state 

the high-energy, unstable form between the substrate and the final product during a chemical reaction

enzyme

a protein that speeds up a chemical reaction without being used up

Glucose synthesis

the process of making glucose

energy coupling

when energy released by an exergonic reaction is used to drive an endergonic reaction.

________ reactions' products have a higher energy state than the reactants

Endergonic

_____ reactions’ products have less energy than their reactants

Exergonic

Positive ∆G =

endergonic reaction

Negative ∆G =

Exergonic reaction

Catalyst

a chemical substance, metal, or protein that helps a reaction happen faster

______ are chemical catalysts that accelerate chemical rxns at physiological temperatures by lowering their activation energy.

Enzymes

Enzymes are usually proteins consisting of one or more __________ chains.

polypeptide

In living organisms, most catalysts are __________ made by cells.

enzymes

When an enzyme and substrate slightly change shape so they fit together better, this is called __________ __________

induced fit

The high-energy, unstable form between the substrate and the final product is called the __________ __________

transition state

When a protein loses its normal shape and stops working properly, it has become __________.

denatured

A type of inhibition in which the inhibitor competes with the substrate for the active site is called __________ inhibition.

competitive

When an inhibitor binds somewhere other than the active site and changes the enzyme’s shape, this is called __________ inhibition.

noncompetitive

When the final product of a pathway inhibits the first enzyme and slows its own production, this is called __________ inhibition.

feedback

The process of making glucose is called glucose __________

synthesis

When energy released by an exergonic reaction is used to drive an endergonic reaction, this is called energy __________.

coupling

Enzymes bind to substrates and catalyze reactions in ____ different ways

four

• Bring substrates together in the correct position

• Weaken substrate bonds so they break more easily

• Provide the best environmental conditions for the reaction

• Form temporary covalent bonds with substrates to help the reaction occur

are the four different ways …

enzymes bind to substrates and catalyze reactions

Enzymes are regulated by _______ and through their _________

cellular respirations ( temperature and pH)

location within a cell

Noncompetitive inhibitors are usually ___________

allosteric

Activators can also enhance enzyme function

allosterically

Name two different cellular functions that require energy that parallel human energy-requiring functions

cell movement and building molecules

Cilia moving

tiny hair-like structures on cells use energy to move substances across the cell’s surface