Bioenergetics and enzymes Flashcards
what does metabolism consist of ?
catabolic and anabolic pathways
what is a catabolic pathway?
release energy by breaking down complex molecules into simpler molecules
what is a anabolic pathway?
consumes energy by using simple molecules to build more complex molecules
what is free energy?
is the energy thatis avalible to do work (contrast to increasing the random motions of particles which is caused by heat)
reactions that release free energy are called what?
exergonic ; they can occur spontaneouslu
reactions that absorb free energy are called what?
endergonic, they do not occur spontaneously and in order to happen they must be coupled to an exergonic reaction
What do enzymes do?
they are molecules that catalyze biochmical reactions, increasing the reaction rate enormously, Most are proteins
How do enzymes make reactions go faster?
make them go faster by reducing their activation energy
What do enzymes not change when catalyzing a reaction?
they do not change the thermodynamic favorability (delta G) of reactions
how do cells control what reactions happen inside the cells?
they alter the identity and amount of the enzymes they produce
Enzymes are highly what to a few substrates?
specific to one or a few substrates
Enzymes have what for binding?
active sites at which the substate binds
what does substrate binding cause?
it causes a change in the shape of the active sites -INDUCED FIT
the active site and the enzyme as a whole are what during a reaction?
both are regenerated during reaction with no new change, and therefore can undertake further catalytic cycles
what are the factors that affect enzyme activity?
substrate concentration
temp
PH
Cofacotrs
Inhibitors and activators
What does the term saturable mean in terms of enzymes?
there are only so many active sites and they can process substrates at some maximun rate
What are cofactors?
cofactos are small non proteinaceous molecules required by some enzymes for their catalytic activity
How do enzymes act in regulated metablic pathways?
sequentially
What is an example of a control circuit?
the product of a pathway inhibits the first enzyme of the pathway (feedback inhibition)
What is Oxidation?
it is the loss of electrons; reduction is the gain of electorns
What is a reduction reaction?
gain of a electron
what is the most common form of electron transfer?
H atoms
Electron transfer may absord or release what?
free energy therefore oxidation-reduction reactions are important in the energy economy of the cell
What are some common Electro carries?
NADH, NADPH, FADH2
