Chapter 5 Flashcards
metabolism
the buildup and breakdown of nutrients within a cell
metabolism chemical reactions provide energy and create substances that
sustain life
catabolic pathways
break down macromolecules into simple component parts
catabolic pathways release or use ATP?
release
anabolic pathways
build up macromolecules by combining simpler moleules
anabolic pathways release or use ATP?
use
anabolic and catabolic pathways are linked by
energy
catabolic reactions provide ________ needed for anabolic reactions
energy
although microbial metabolism can cause disease and food spoilage many pathways are
beneficial rather than pathogenic
is catabolism exergonic or endergonic
exergonic
is anabolism exergonic or endergonic
endergonic
metabolic pathways are sequences of
enzymatically catalyzed reactions in a cell
metabolic pathways are determined by
enzymes
enzymes are encoded
genes
how is ATP an intermediate between catabolism and anabolism
because catabolism reactions release the energy needed to undergo anabolism reactions
collision theory
chemical reactions occur when atoms, ions and moleules collide
activation energy
collision energy required for a chemical reaction to occur
reaction rate
frequency of collisions containing enough energy to bring about a reaction
reaction rate can be increased by
enzymes, increasing temp, pressure or concetration
catalysts
speed up chemical reactions with out being altered
enzymes are biological
catalysts
enzymes act on a specific ________ and lower the ________ ______
substrate, activation energy
substrate contacts the enzymes active site to form an ________ _______ ______
substrate is transformed and rearranged into _______, which are released from the enzyme
enzyme substrate complex, products
enzymes are ______ after the chemical reaction
unchanged
enzymes have _______ for a particular substrate
specificity
___________ _____ is the number of substrate moleules an enzyme converts to product per second
turnover number
names of enzymes usually end in ___
ase
enzymes are grouped based on the
reaction they catalyze
oxidoreductase
oxidation reduction reactions
transferase
transfer function groups
hydrolase
hydrolysis
lyase
removal of atoms without hydrolysis
isomerase
rearrangement of atoms
ligase
joining of molecules uses ATP
some enzymes consist entirely of
proteins
most enzymes consist of
apoenzyme and cofactor
apoenzyme
protein portion (inactive when alone)
apoenzyme must be activated by
cofactor
cofactor
nonprotein component
if the cofactor is organic then it is known as
coenzyme
holoenzyme
apoenzyme plus cofactor (whole active enzyme form)
assist enzymes by being electron carriers
nicotinamide adenine dinucleotide (NAD+)
nicotinamide adenine dinucleotude phosphate (NADP+)
flavin adenine dinucleotide (FAD)
coenzyme A (CoA)
many coenzymes are derived from
vitamins
2 most important enzyme components
NAD+ and NADP+
NAD+ is primarily involved in
catabolic
NADP+ is primarily involved in
anabolic
NAD+ and NADP+ both contain derivatives of B vitamin ____ and both function as _________ ___
niacin, electron carriers
FAD is a derivative of the b vitamin ______ and functions as a _________
riboflavin, electron carrier
CoA is a derivative of the b vitamin _______ and this functions as
Pantothenic acid, synthesis and breakdown of fats and is in the Krebs cycle
as the temp increases the chemical reactions
increase
high temp and extreme pH can
denature proteins
if the concentration of substrate is high the enzyme catalyzes at is
maximum rate
inhibitors can either be
competitive or noncompetitive
competitive inhibitors
fill the active site of an enzyme and compete with the substrate
inhibitors can be
reversible or irreversible
competitive inhibitors chemical make up is similar to
normal substrate
competitive inhibitors go or do not go under reaction?
DO NOT
noncompetitive inhibitors
interact with another part of the enzyme rather than the active site
noncompetitive inhibitors bind with the
allosteric site
noncompetitive inhibitors undergo allosteric _______
inhibtion
noncompetitive inhibitors indirectly change the shape of the
active site, rendering the enzyme nonfunctional
feedback inhibition
end product of a reaction allosterically inhibits enzymes from earlier in the pathway
feedback inhibition stops the cell from making more of a substance than it needs and keeps it from wasting
chemical resources
ribozymes
RNA that functions as catalysts by binding to substrates and acting upon them
ribozymes are or are not used up in the reaction?
not used up
ribozymes are frequently used in cells to
cut and splice RNA
ribozymes are also involved in
protein synthesis in ribosomes
