Chapter 8 An intro to metabolism

From where do cells extract their energy? Where do they apply it?

From where do cells extract their energy? Where do they apply it?

Sugars and other fuels. The energy is applied to work.

Some organisms are able to convert their energy to what?

light (example: bioluminescence)

An organism’s metabolism transforms ____ and ____, subject to the laws of ____.

matter, energy, thermodynamics

Metabolism accounts for all the organism’s what?

chemical reactions

Metabolism is an emergent property of ____ that arises from orderly ____ between ____.

life, interactions, molecules

A metabolic ____ starts within a specific ____ and ends up with a ____.

pathway, molecule, product

Each step of metabolism is catalyzed (caused or accelerated) by a one specific ____.

enzyme

Catabolic pathways release energy by break down ____ molecules into ____ compounds.

complex, simpler

Cellular respiration is the breakdown of ____ in the presence of ____ and is an example of ____.

glucose, oxygen, catabolism

Anabolic pathways consume energy to:

build complex molecules from simpler ones.

Synthesis (creation) of protein from amino acids is an example of what?

anabolism

Bioenergetics is the study of how ____ ____ through living organism.

energy flows

Energy is the capacity to cause a ____.

change

Energy exists in numerous ways, some of which are capable of performing ____.

work

Kinetic energy is the type of energy related to ____.

motion

Heat (thermal energy) is ____ energy associated with ____ ____ of atoms or molecules.

kinetic, random movement

Potential energy is energy that matter has due to its ____ or ____.

location or structure

Chemical energy is ____ energy available for ____ in a chemical reaction.

potential, release

Energy can be converted to ____ ____.

different forms

Thermodynamics

study of energy transformations

In an isolated system is unable to ____ ____ or ____ with its surroundings. An example of this would be coffee in a thermos.

exchange energy, matter

An open system allows ____ and ____ to be transferred between the system and its surroundings. ____ are technically open systems.

energy, matter, Organisms

According to the first law of thermodynamics, energy of the universe is _______; energy can be _______ or _______, but it cannot be _______ nor _______

constant, transferred, transformed, created, destroyed

First law of thermodynamics is also called:

principle of conservation of energy

According to the second law of thermodynamics, every energy transfer or transformation has some ____ form of energy and is often lost as ____.

useless, heat

2nd law of thermodynamics: every energy transfer or transformation increases ____ (____) of the universe.

entropy, disorder

Organisms don’t violate the 2nd law by building order in our cells, but we still increase the overall disorder in the universe. True or false.

True

Living cells unavoidably convert ____ forms of energy to ____.

organized, heat

Spontaneous processes occur ____ ____ ____, it must increase the ____ of the universe.

without energy input, entropy

Cells technically make ____ ____ from less ____ ____.

ordered structures, ordered materials

Organisms also replace ordered forms of _______ and _______ with less ordered _______.

matter, energy, forms

Energy flows into an ____ in the form of ____ and exits in the form of ____.

ecosystem, sunlight, heat (ex. body heat and evaporative cooling)

Does the evolution of more complex organisms does or does not violate the second law of thermodynamics?

They do not violate the law.

The entropy (disorder) may _______ in an organism, but the universe’s ____ ____ increases.

decrease, total entropy

The _______ _______ _______ of a reaction tells us whether or not the reaction occurs spontaneously or not.

free energy change

biologists have to determine the ____ ____ that occur in chemical reactions in order to know which reactions occur ____ and which need an ____ ____.

energy changes, spontaneously, energy input

_____ _____ (delta G, _____ free energy) is a living system’s energy that can do _____ when _____ and _____ are uniform (constant), as in a living cell.

Free energy, Gibbs, work, temperature, pressure

Only the ____ delta G are spontaneous.

negative

Spontaneous processes can be utilized to perform ____.

work

Free energy is a measure of a system’s ____, it tendency to change to a more ____ ____.

instability, stable state

During a spontaneous change, free energy ____ and the stability of a system ____.

decreases, increases

Equilibrium is a state of ____ ____.

maximum stability

A process is only spontaneous and perform work only when its moving ____ ____.

toward equilibrium

An exergonic reaction proceeds with a net ____ of free energy and is ____.

release, spontaneous

An endergonic reaction ____ free energy from its surroundings and is ____.

absorbs, non-spontaneous

3 main kinds of work a cell is capable of:

chemical, transport, mechanical

in order to do work, cells manage energy resources through ____ ____, the use of an ____ process to drive an ____ one.

energy coupling, exergonic, endergonic

Most energy coupling in cells is mediated by ____.

ATP

ATP (adenosine triphosphate) is the cell’s ____ ____.

energy shuttle

ATP is composed of ____ (a ____), ____ (a ____ base), and three ____ ____.

ribose, sugar, adenine, nitrogenous, phosphate groups

Bonds between phosphate groups of ATP’s tail can be broken by ____.

hydrolysis

Energy is released from ____ when the ____ phosphate bond is ____.

ATP, terminal, broken

The release of energy comes from the ____ change to a state of ____ free energy, not from the phosphate bonds themselves.

chemical, lower

The three types of cellular work (mechanical, transport, and chemical) are powered by ____ of ____.

hydrolysis, ATP

Inside a cell, the energy from the ____ reaction of ____ ____ can be used to drive an ____ reaction.

exergonic, ATP hydrolysis, endergonic

Overall, coupled reactions are ____, and there’s a

exergonic

ATP drives endergonic reactions by ____, transferring a phosphate group to some other molecule like a reactant. The recipient molecule is now called a ____ ____.

phosphorylation, phosphorylated intermediate

Transport and mechanical work in the cell are also powered by ____ ____, which leads to a change in protein ____ and ____ ability.

ATP hydrolysis, shape, binding

ATP is a ____ ____ that is regenerated by addition of a ____ group to ____ ____ (ADP).

renewable resource, phosphate, adenosine diphosphate

The energy to ____ ADP comes from ____ ____ in the cell.

phosphorylate, catabolic reactions

The ATP cycle is a revolving door through which energy passes during its transfer from ____ to ____ pathways.

catabolic, anabolic

Photosynthesis does not take the place of cellular respiration in plants. Plant cells also conduct cellular respiration anyways.

No definition

A catalyst is a chemical agent that ____ a reaction without being ____ by the reaction.

accelerates, consumed

An enzyme is a ____ ____.

catalytic protein

Hydrolysis of ____ by the enzyme ____ is an example of an enzyme-catalyzed reaction.

sucrose, sucrase

Enzymes are ____ for the reactions they catalyzed. Their ____ determines what kinds of reactions they will catalyze.

specific, structure

Enzymes ____ the required ____ energy (which is needed to ____ (start or accelerate) a reaction).

lower, activation, catalyze

the initial energy needed to start a chemical reaction is called the ____ ____ of ____ or activation energy (E underscore A).

free energy, activation

Enzymes ______ reactions by lowering the EA barrier

catalyze

Enzymes do not affect the change in free energy (Gibb’s free energy), they only hasten reactions.

No definition

Activation energy is often supplied in the form of ____ ____ that the reactant molecules ____ from their ____.

thermal energy, absorb, surroundings

Reactant that an enzyme acts on is called the enzyme’s ____.

substrate

Enzyme binding to its substrate forms a ____-____ ____.

enzyme substrate complex

Active site is the region on an enzyme where the ____ binds.

substrate

Induced fit of a substrate brings ____ groups of the active site into ____ that enhance their ability to ____ the reaction.

chemical, positions, catalyze

The active site can lower an EA barrier by:

1. ____ substrates correctly

2. ____ substrate ____

3. Providing a ____ ____

4. ____ bonding to the ____

1. orienting

2. straining, bonds

3. favorable microenvironment

4. covalently, susbstrate

An enzyme’s activity can be affected by:

1. Environmental factors like ______ and ______

2. ______ that specifically ______ the enzyme

1. temperature, pH

2. Chemicals, influence

Each enzyme has an ____ ____ and ____ ____ in which it can function.

optimal temperature, optimal pH

Denaturation of an enzyme:

Doesn’t work well or doesn’t work at all

Optimal conditions ____ the most ____ ____ for the enzyme molecule.

favor, active shape

Memorize what enzymes do what in Figure 8.17

Memorize for MCQ

Cofactors are ____ enzyme ____.

nonprotein, helpers

Cofactors can be ____ (like metal or ionic form) or ____.

inorganic, organic

An organic cofactor is called a ____.

coenzyme

Coenzymes can also include ____.

vitamins

Competitive inhibitors bind to the ____ ____ of an enzyme, competing with the ____.

active site, substrate

Noncompetitive inhibitors binds to another part of an enzyme, causing it to ____ ____ and making the active site ____ ____.

change shape, less effective

Examples of inhibitors

toxins, antibiotics, poisons, pesticides (TAPP)

Enzymes are proteins ____ by ____.

encoded, genes

Mutations (_______) in genes lead to changes
in _______ _______ composition of an enzyme

changes, amino acid

Altered amino acids in enzymes may result in novel (new and original) ______ ______ or novel ______ ______ ______. Under new environmental conditions a novel form of an enzyme might be favored.

enzyme activity, altered substrate specificity

Slides 61 and 62 are fun facts not required to know for the exam.

No definition

Chemical chaos would result if a cell’s metabolic pathways weren’t ____ ____. A cell does this by switching _______ or _______ the genes that encode specific _______ or by regulating the _______ of enzymes.

tightly regulated, on, off, enzymes, activity

Allosteric regulation may either ____ or ____ an enzyme’s activity.

inhibit, stimulate

Allosteric regulation occurs when a _______ molecule binds to a protein at one site and affects the protein’s _______ at another site.

regulatory, function

Most allosterically regulated enzymes are made from ____ ____.

polypeptide subunits

Each enzyme has ____ or ____ forms.

active, inactive

The binding of an activator ____ the ____ form of the enzyme.

stabilizes, active

The binding of an inhibitor ____ the ____ form of the enzyme.

stabilizes, inactive

Cooperactivity is a form of ______ regulation that can ____ enzyme activity.

allosteric, amplify