Chapter 3 Study Questions (Part 1) Flashcards
what is free energy?
energy that can be extracted from a molecule to do work
what can free energy tell you about a chemical reaction?
exergonic or endergonic
what does exergonic reaction mean? (3)
exergonic. free energy is negative. reactants greater than products. catabolic.
what does endergonic reaction mean? (3)
free energy is positive. endergonic. products greater than reactants. anabolic.
what does free energy is positive mean? (3)
free energy is positive. endergonic. products greater than reactants. anabolic.
what does free energy is negative mean? (3)
exergonic. free energy is negative. reactants greater than products. catabolic.
what does reactants greater than products mean? (3)
exergonic. free energy is negative. reactants greater than products. catabolic.
what does products greater than reactants mean? (3)
free energy is positive. endergonic. products greater than reactants. anabolic.
what does anabolic mean? (3)
free energy is positive. endergonic. products greater than reactants. anabolic.
what does catabolic mean? (3)
exergonic. free energy is negative. reactants greater than products. catabolic.
when do exergonic reactions proceed spontaneously?
when the activation energy barrier is overcome.
why is it a good thing that we only extract ~1/3 of the energy from glucose?
you have to burn glucose to get all the energy out of it and that would be lethal to us.
define mass action
increasing reactants moves the reaction to the right. increasing products moves the reaction to the left.
if ATP is the energy currency of the cell, why doesn’t a cell store chemical energy as ATP?
we can’t! ATP spontaneously hydrolyzes over time
define hydrolyze
break down
what does ATP hydrolyze into?
ADP and AMP
what is the induced fit model of enzyme catalysis, and how does it explain that an enzyme can break a chemical bond without requiring an input of energy? (3)
- enzyme catalytic site has a shape complementary to its substrate
- interaction between substrate and catalytic site causes a conformational (shape) change in the catalytic site that breaks bonds
- substrate is converted into the product and is released from the catalytic site
what is the difference between a substrate and a ligand?
S: the reactant, binds to an enzyme
L: interact with receptors, bind to stuff, reversible reaction
what is gluconeogenesis?
the creation of new glucose
what type of reaction is gluconeogenesis?
reactants lower than products, free energy is positive, endergonic, anabolic.
why is the activation barrier a good thing?
otherwise it would be all product, no reactants, and that would be bad
are covalent bonds involved with ligands?
no!
what is the role of enzymes?
lower the activation energy barrier so that a chemical reaction can occur
what is a redox reaction?
involves a transfer of electrons
