Enzymes Flashcards
Biological Molecules
Lipids
Carbohydrates
Proteins
Nucleic Acid
diverse group of water-insoluble
biological molecules: Fats, Phospholipid and sterols
Lipids
Energy stores
Fats
major
components of membrane.
Phospholipids and sterols
polyhydroxy aldehydes
and ketones with the
general formula of
(CH2O)n.
Carbohydrates
most complex and most abundant
organic molecules containing at least one
carboxyl group and one amino group.
Proteins
DNA carries coded information,
arranged into genes, that is passed from each
cell to its daughter cells and from one
generation to the next; RNA instrumental in
translating the coded message of DNA into
sequences of amino acids during synthesis of
protein molecules
Nucleic Acid
The process of increasing the rate of
reaction with the use of a catalyst.
Catalysis
any substance that increases rate
of reaction upon addition to a certain
reaction .
Catalyst
catalyst of biochemical reactions (biological
catalysts)
Enzymes
lowers
the activation
energy
Enzymes hastens the reaction
protein
hydrolysing) hydrolyses any
peptide bond in which the
carbonyl group belongs to a
phenylalanine, tyrosine, or
tryptophan residue.
chymotrypsin (proteolytic
enzyme present in the
intestine)
- highly specific nature of most enzymes arises
from the close and complementary fit between
enzymes and substrate in a special portion of the
enzyme surface - where the substrate can fit like a lock-and-key
mechanism
Active site
catalytic potency
of an enzyme
Enzyme activity
number of
reactions catalyzed per second by the
enzyme
Turnover number
small organic molecules that
act as cofactors
coenzymes
enzyme minus its cofactor;
cannot function without its
cofactor/coenzyme
apoenzyme
covalently attached
cofactors, part of the enzyme molecule
vitamins
Cofactor (coenzyme, prosthetic group or metal ion) +
apoenzyme =
holoenzyme
- used in the living cell as a means of
controlling enzymatic reactions - discovered important features of the active
sites and of the mechanisms of enzyme action - enzymes can be irreversibly (toxins) or
reversibly inhibited
enzyme inhibition
2 types of enzyme inhibition
competative and noncompetative
- caused by molecules
that react directly with
the active site of the
enzyme - can be reversed by
an increase in
substrate
concentration
-most competitive
inhibitors are
substrate analogs
Competative inhibition
- caused by molecules that bind to a region(s)
of the enzyme outside the active site - reversed by dilution or removal of the
inhibitor - chemical structure of noncompetitive
inhibitors typically differs from that of the
substrate.
Noncompetitive inhibition
alters the tertiary structure
of the enzyme thus changing the
conformation of the active site
Allosteric site
interaction of the end
product occurs in the
allosteric site, making
the end product an _______
Allosteric inhibitor
Two kinds of energy yielding metabolic
pathways in animal
tissues:
Aerobic metabolis and Anaerobic metabolism
food molecules are
completely oxidized to
carbon dioxide and
water by molecular
oxygen; energy yield is
far greater
Aerobic metabolism
food molecules are
oxidized incompletely
to lactic acid (lactate);
- absence of
oxygen
Anaerobic metabolism
