Ch 5 Metabolism Part 1 Flashcards
the sum of all chemical reactions within a living organism
“energy balancing act”
metabolism
enzyme regulated chemical reaction that releases energy (building block for anabolic)
breakdown of complex organic compounds to simpler ones
catabolism
reactions which use water and chemical bonds are broken
hydrolytic
produce more energy than they consume
exergonic
enzyme regulated energy requiring reactions
building up of complex organic molecules from simpler ones
anabolic or biosynthetic
anabolism
reactions that release water
dehydration synthesis
consume more energy than they produce
endergonic
what does ATP do
stores energy derived from catabolic reactions and releases it later to drive anabolic reactions
sequences of chemical reactions that are determined by enzymes
metabolic pathways
all atoms, ions, and molecules are continuously moving and are thus colliding with one another
collision theory
what is collision determined by
velocities of particles, energy and chemical configurations
this is collision energy required for a chemical reaction
also the amount of energy needed to disrupt the stable electronic configuration
activation energy
frequency of collisions containing sufficient energy to bring about a reaction
this can be increased by increasing the temp
reaction rate
when does the number of collisions increase
when pressure increases and the reactants are more concentrated
these speed up a chemical reaction without being permanently altered
catalysts
what serve as biological catalysts
typically accelerate chemical reactions
have an active site
and can exist in both active and inactive forms
enzymes
this is formed by temperature binding of enzyme and reactants enables the collisions to be more efficient
enzyme substrate complex
max number of substrate molecules an enzyme molecule converts to product each second
turnover number
these usually end in ase
consists of both apoenzyme and a cofactor
enzyme
what is a apoenzyme
protein
what is a cofactor
nonprotein
what do the apoenzyme and cofactor together form
holoenzyme
what is the cofactor if it is organic
coenzyme
what is involved in catabolic (energy yielding reactions)
NAD+
what is involved in anabolic (energy requiring reactions)
NADP+
what function as electron carriers
NAD+, NADP+, FAD, FMN, CoA
this has a role in synthesis and breakdown of fats
CoA
what do enzymes lower
the activation energy of chemical reactions
what are the five steps of enzyme action
1) surface of substrate contacts active site
2) temp compound forms
3) substrate molecule is transformed
4) transformed molecules are released from enzyme molecule
5) unchanged enzyme can now react with other substrates
what are the factors that influence enzymatic activity
temperature, pH, substrate concentration, presence/absence of inhibitors
loss of characteristic 3D structure(loses catabolic activity) breakage of hydrogen bonds
denaturation
active site is always occupied by substrate or product molecules
saturation
fill the active site of an enzyme and compete with the normal substrate for the active site
its shape and chemical structure are similar to normal substrate
competitive inhibitors
do not compete with the substrate for the enzyme’s active site
interact with another part of the enzyme
noncompetitive inhibitors
this inhibitor binds to a site of the enzyme other than the substrate’s binding site (enzymes’s activity is reduced)
allosteric inhibition
cyanid and fuloride permanently inactivate enzymes
enzyme poisons
this is also known as end product inhibition
feedback inhibition
what does feedback inhibition do
stops the cell from making more of a substance than it needs
generally acts on the first enzyme in a metabolic pathway
this is a type of RNA
functions as catalysts, have active sites that bind to substrates and are not used up in chemical reactions
act on strands of RNA
ribozyme
what does ATP have
high energy bonds or unstable bonds
can be released quickly and easily
provide the cell with readily available energy for anabolic reactions
this is the removal of electrons from an atom or molecule, often produces energy
oxidation
this occurs when something gains one or more electrons
reudction
what is another name for an oxidation-reduction reaction
redox reaction
loss of hydrogen atoms
dehydrogenation
why do cells use these reactions in catabolism
to extract energy from nutrient molecules
