BIOL 2010 Exam 3

Ch. 8,9, and 10

What makes cellular activity possible? (two things)

Energy and enzymes

______ directs which reactions occur and when?

enzymes

What works to help cells acquire and use energy?

Enzymes

What is described as an ordered series of chemical reactions that build up or break down molecules?

metabolic pathways

What is defined as the energy of motion?

kinetic energy

What is defined as stored energy?

potential energy

What is defined as energy stored in chemical bonds?

chemical energy

The amount of potential energy in covalent bonds depends on _______ and ______ of shared electrons

configuration and position

Longer, weaker bonds with equally shared electrons have ________ _______ energy

high potential

Shorter, stronger bonds with unequally shared electrons have _____ _____ energy

low potential

What makes a bio molecule organic?

C-C and C-H bonds

In _________ chemical reactions products that are formed have ____, stronger covalent bonds than reactants

exothermic shorter

In exothermic chemical reactions, the potential energy in bonds ________

decreases

In _________ chemical reactions products that are formed have ____, weaker covalent bonds than reactants

endothermic longer

In endothermic chemical reactions, the potential energy in bonds ________

increase

Energy from bonds can convert to ____ or ____ energy

thermal light

What is the first law of thermodynamics?

energy cannot be created or destroyed only transferred

Delta H describes the change in ______

enthalpy

The change is delta H is described by the equation……

products minus substrates

Enthalpy includes the _____ _____ in bonds of molecules

potential energy

What type of reaction is described as the release of heat?

Exothermic

In an exothermic reaction delta H is _______

negative

In an exothermic reaction, products have ______ potential energy than the substrates

less

What type of reaction absorbs the energy of heat?

endothermic

In an endothermic reaction, delta H is ______

positive

In an endothermic reaction, products have ______ potential energy that the reactants

more

What measures the amount of disorder?

entropy (s)

A positive delta S means _____ order

less

What type of reaction is an example of a positive delta S?

Catabolic

A negative delta S means there is _____ order

more

What type of reaction is an example of a negative delta S?

anabolic

What law explains that the total entropy always increases in a system?

second law of thermodynamics

What determines whether a reaction is spontaneous or requires added energy to proceed?

Gibbs free energy (G)

If a reaction is spontaneous it requires _____ energy

no

A non-spontaneous reaction ______ energy

requires

The standard free energy change equation is Delta G=………

Delta H minus T times delta S

When delta G is less than zero the reaction is _______

spontaneous

When delta G is less than zero, the reaction is spontaneous and is called _______

exergonic

When delta G is greater than zero the reaction is _______

nonspontaneous

When delta G is greater than zero, the reaction is nonspontaneous and is called ________

endergonic

When delta G is equal to zero, the reaction is at _______

equilibrium

T/F: All spontaneous reactions happen quickly.

F

For most reactions to happen, higher _____ is needed to increase the number of collisions

concentrations

For most reactions to happen, higher ______ is needed to increase the reaction rate

temperature

For most reactions to happen one or more chemical bonds have to _______

break

If you have a -ΔH and a +ΔS, the reaction will be spontaneous at ________ temperatures

all

If you have a +ΔH and a -ΔS, the reaction will be spontaneous at _______ temperatures

no

If you have a +ΔH and a +ΔS, the reaction will be spontaneous at _______ temperatures

higher

If you have a -ΔH and a -ΔS, the reaction will be spontaneous at ________ temperatures

low

For most reactions to proceed, other chemical bonds have to ______

form

For most reactions to proceed, substrates must collide in a specific ________

orientation

What is it called when the chemical energy released from one reaction drives another reaction?

Energetic coupling

Energetic coupling occurs by transferring ______ or ______ ______

electrons phosphate groups

Chemical reactions that involve electron transfer is called ________

Redox Reactions

What is described as the loss of an electron(s)?

oxidation

What is described as the gain of electron(s)?

Reduction

T/F: Reduction-oxidation reactions always occur together.

T

Oxidation represent the first half of energetic coupling reactions by being ______

exergonic

Reduction represents the second half of energetic coupling reactions by being ______

endergonic

During redox reactions, electrons may be gained or lost by changing the number of electrons in the ______ _____ of the atom

valence shell

During redox reactions, electrons may be gained or lost by transferring electrons to a new _____ _____

covalent bond

Electrons can be transferred from electron _____ to electron ______

donor acceptor

Most electrons acceptors gain ______ ______ as they are reduced

potential energy

Electrons are usually accompanied by a ______

proton

Reduction often ______ a proton

adds

Oxidation often _____ a proton

removes

What is the name of FAD?

Flavin adenine dinucleotide

FAD accepts _____ electrons and _____ protons to form FADH2

two two

What is the name of NAD+?

Nicotinamide Adenine Dinucelotide

NAD+ accepts ______ electrons and _____ protons

two one

T/F: ATP doesn’t have a lot of potential energy

F

ATP transfer energy via it’s ______

phosphate

Where is the potential energy stored in ATP?

Between the three negatively charged phosphates

The negative charges of the phosphate groups _____ each other

repel

ATP reacts with water during the _______ reaction

hydrolysis

Hydrolysis reactions involving ATP, breaks the bond between the ______ and _____ phosphate groups

second third

What is the result of ATP being hydrolyzed?

ADP

ATP being hydrolyzes is a highly ______ reaction

exergonic

During the hydrolysis of ATP how much total energy is released per mole of ATP?

7.3 kcal

What describes the addition of a phosphate group to a target molecule?

Phosphorylation

The energy released by hydrolyzing ATP is used for _____ _____

cellular activity

Adding a phosphate group ______ the potential energy of a reactant

increases

T/F: Phosphorylation can couple exergonic and endergonic reactions

T

For a reaction to happen, enough _____ ______ is needed to get over the activation hill and reach the transition state

kinetic energy

What describes the intermediate point between breaking old bonds and forming new ones?

Transition State

What is symbol describes the amount of free energy released that is available to do useful work?

ΔG

For a reaction to happen, molecules must ____ in a precise orientation

precise

Enzymes are ______

catalysts

T/F: An enzyme can be used for all types of reactions

F

Reactants that undergo chemical reactions by binding to an enzyme is called ______

substrates

Substrates bind to an enzyme’s _____ _____

active site

____ _____ binding breaks bonds and form to make products

Active site

Active site binding helps ______ collide in precise orientations

substrates

T/F: Enzymes don’t undergo conformational change.

F

When the substrate is binding to the active site, the enzyme may change _____.

shape

What is it called when an enzyme changes its shape to fit the substrate better?

Induced fit

Substrates that enter the active site are held in place by _____ bonding

hydrogen

Substrates that enter the active site are held in place by weak interactions with _____ _____ residues in the active site

amino acid

When the substrates enter the active site the bonds in the substrate are ______ to form the transition state

destabilized

Enzymes _______ activation energy required for the reaction to proceed

decrease