Chapter 8 - Metabolism Flashcards Preview

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Flashcards in Chapter 8 - Metabolism Deck (44):

Define: Metabolism

It is the totality of an organisms chemical reactions.


What is a catabolic pathway?

Pathway that breaks down complex molecules into simpler compounds.

Ex. In cellular respiration where a glucose molecule is broken down in the presence of carbon dioxide and water


What is an anabolic pathway?

It consumes energy to build complicated molecules from more simpler ones

Ex. Synthesis of Amino acids and the also the synthesis of proteins from Amino acids.


What is energy?

Capacity to cause change



What is kinetic energy?

It is energy associated with movement.


What is thermal energy?

Thermal energy is a type of kinetic energy that is associated with the random movements of atoms or molecules.


What is potential energy?

Potential energy is that is not kinetic. Stored energy. Energy that matter possesses because of its location or structure.


What is chemical energy?

Molecules posses energy because of the arrangement of electrons in the bonds between atoms.

Available energy that can be released when needed.


What is the first law of thermodynamics?

Energy can be transferred and transformed, but it cannot be created or destroyed.

Principle of conservation energy.


What is the second law of thermodynamics?

Every energy transfer or transformation increases the entropy of the universe.


What is entropy?

Disorder or randomness

A measure of disorder.


Explain a spontaneous process

Happens on its own
Not necessarily immediate
Explosion vs. rust


Define Free Energy.

Energy that can perform work
When temperature and pressure are uniform (stays the same) throughout system


What is enthalpy?

Often considered by biologists at the total amount of energy


What is entropy?

The energy list to surroundings.


What is the Gibbs free energy equation?



What does ΔG stand for in the Gibbs free energy equation?

Change in free energy


What does the ΔH stand for in the Gibbs free energy equation?

Change in the systems enthalpy (total energy)


What does ΔS stand for in the Gibbs free energy equation?

Change in systems entropy


What does the T stand for in the Gibbs free energy equation?

Absolute temperature in Kelvin (K=Celsius + 273)


What happens when the change in free energy (ΔG) is less than zero?

It is an exergonic reaction


What happens when the change in free energy (ΔG) is greater than 0?

It is an endergonic reaction


What is an exergonic reaction?

When a reactant goes through a process and the energy is released. The product is usually less than the reactant.

Usually a spontaneous reaction.


What is an endergonic reaction?

The reactants go through a process and the energy is brought into the end products.

There is more products than the reactants that started.


What is ATP and what does it stand for?

Adenosine Triphosphate

Organisms use ATP as a source of energy

Made up of:
Three phosphate groups


What is the hydrolysis process of ATP?

ATP will have a water molecule brought into the structure and a phosphate will leave and energy is realeased.


What is ADP?

The form of in which with the addition of a phosphate will turn to ATP

Basically ATP without the energy. It has already been released.


What does ATP do in a chemical aspect?

It will speed up or push the endergonic reactions that would not occur spontaneously

Ex. Synthesis of polymers from Monomers


What does ATP do in a transporting aspect?

It will help pump substances across membranes that are going against the directions of spontaneous movement.


What does ATP do in the mechanical aspect?

Help contraction of the muscle cells, help in the movement of chromosomes during cellular reproduction.


What are enzymes?

It is a macromolecule that acts as a catalyst, it is a chemical agent that speeds up a reaction without being effected itself. It makes substrates into products.

Ex. Sugar will sit for years without breaking down but when you add sucrase (enzyme) it will brake down in seconds.


What is activation energy?

Energy needed to contort the reactant molecules so the bonds can break.


How does a substrate turn into a product?

A substrate is bound into a enzyme (in the little pocket that enzymes have) it will then become an enzyme-substrate complex where the substrate will form weak bonds with the enzyme and will change its shape.

With the hanged shape it can then make more weak bonds and hold it in place.


Why does enzymatic activity increase in higher temperatures?

Because the substrates will collide with the enzymes that have active sites more frequently since the molecules are moving faster.


What do most enzymes in the human body work better in pH of 6-8?

Because the more acidic environment the more it will denature the enzymes.

Exceptions are pepsin which are made for that kind of environment.

Trypsin is in more of the alkaline environment in the human intestine.


What is a cofactor?

They are enzymes "helpers" many enzymes require cofactors to function, often inorganic such as zinc, copper, or iron


What is a coenzyme?

It is a cofactor that is an organic molecule; usually comes from vitamins.


What are inhibitors and how many types are there? What are thy?

Certain chemicals that will inhibit the action of enzymes.

2 types:


What do competitive inhibitors do?

They will reduce the productivity of an enzyme by blocking the active sites where the substrates cannot bond with.


What do noncompetitive inhibitors do?

They slow down the break down processes that enzymes have by binding to a different part of an enzyme. It will cause a reaction that will change the shape of enzymes where the active site then has a harder time breaking things down.


What is the allosteric regulation?

A term used to describe any case in which a protein's function at one site is affected by the binding of a regulatory molecule to a separate site.

It may activate the site
Or it may inhibit the site


What does an allosteric activator do?

The binding of an activator to a regulatory site stabilizes the shape that has functional active sites. When an enzyme is inactive it makes it active and produce a ton more products.


What do allosteric inhibitors do?

They will stabilize the inactive form of the enzyme.


What is cooperativity?

Binding one active site locks all subunits to inactive confirmation.

Amplifies the response of enzymes to substrates.