AP BIOLOGYChapter 8

Metabolism

The _____ Law of Thermodynamicsstates that energy can be transformedand transferred by NEVER created or destroyed

Anabolic pathways consume energy to build molecules

release energy by breaking down molecules

The measure of disorder or randomness(symbolized by S)

FIRST

→

entropy

The _______ Law of Thermodynamicsstates that every energy transfer or transformation increases the entropy of the universe.

Chemical reactions with a NEGATIVEfree energy (- Δ G) are ____________

endergonic exergonic

SECOND

exergonic

Chemical reactions with a POSITIVEfree energy (+ Δ G) are ____________

endergonic exergonic

Most enzymes belong to which groupof macromolecules?

Molecules that speed up chemical reactions are called ____________

endergonic

proteins

catalysts

Energy associated with moving objects is called _______ energy

Catabolic pathways consume energy to build molecules

release energy by breaking down molecules

Chemical energy is a form of ___________ energy kinetic potential

kinetic

→

potential

Reactions that release free energyare called ______________

exergonic endergonic

The hydrolysis of ATP is a ________ ΔG reaction.

Catalytic proteins that speed up chemical reactions in living things are called

____________

exergonic

negative

enzymes

Reactions that absorb free energyare called ______________

exergonic endergonic

Chemical reactions with a NEGATIVEfree energy (- Δ G) are ____________

spontaneous nonspontaneous

Region on an enzyme where regulatory molecules can bind = ______________

endergonic

spontaneous

Allosteric site

Chemical reactions with a POSITIVEfree energy (+ Δ G) are ____________

spontaneous nonspontaneous

The initial investment of energy for starting a chemical reaction is called

the _______________

The place on an enzyme where the substrate attaches = _____________

nonspontaneous

Activation energy OREnergy of activation

active site

Chemical reactions with a NEGATIVEfree energy (- Δ G) are ____________

spontaneous nonspontaneous

Which kinds of bonds hold the substrate to the active site of an enzyme?

Nonprotein “helpers” for catalytic activty are called ______________

spontaneous

Weak interactions like hydrogen & ionic bonds

cofactors

If a cofactor is an organic molecule it is called a ____________

Which kind of food molecules oftenact as coenzymes?

A molecule that mimics a substrate, binds to the active site, and reduces the activity of an enzyme is called a(n) _______________ inhibitor.

coenzyme

vitamins

COMPETITIVE

______________ inhibitors slow down enzymatic reactions by binding to a site other than the active site and causing a change in the enzyme’s shape

In ___________ inhibition, a metabolic pathway is switched off by the binding of its end product.

The change in the shape of the active site of an enzyme after the substrate attaches so that it binds more snugly

is called _____________

NONCOMPETITIVE

FEEDBACK

INDUCED FIT

When the binding of one substrate molecule primes an enzyme to accept additional substrate molecules more readily it is called ______________

COOPERATIVITY

The arrow in the diagram is showing the _________________ of this reaction.ACTIVATION ENERGY

The arrow in the diagram is showing the ______________________ of this reaction.CHANGE IN FREE ENERGY (ΔG)

This reaction has a ___ Δ G because the energy of the products is greater then the reactants

+

This reaction has a ___ Δ G because the energy of the products is less then the reactants

-

How would adding an enzyme change the graph of this reaction?

Enzymes lower the activation energy of chemical reactions but don’t change theenergy of the products

Cells manage their energy resources by using the energy from exergonic (-ΔG) reactions to drive endergonic (+ΔG) reactions in a process called

____________________

ADP + Pi → ATP

This is a __ ΔG reaction.Energy coupling

+

Cellular respiration uses glucose, which has a high level of free energy and releases CO2 and H2O which have low levels of free energy.

Is respiration spontaneous or not?

Is it exergonic or endergonic?spontaneous

exergonic

How does the 2nd LAW of thermodynamics help explain the diffusion of a substance across a membrane?

The 2nd Law is the tendency toward randomness. Having equal concentrations on both sides of a membrane is more random than unequal concentrations. Diffusion from high concentration to low INCREASES THE ENTROPY as mandated by the 2nd law

If living things take simpler substances and build them into complicated systems (increase entropy), why does this NOT VIOLATE the 2nd LAW of thermodynamics ?

Living things are OPEN systems and must constantly take in energy and materials

from outside to maintain the increase in entropy