Enzymes and Vitamins Flashcards
are proteins that catalyze the body’s chemical reactions
Enzymes
They can increase the rate of reaction as much as ___ by reducing the activation energy without affecting the equilibrium.
106
Enzymes reducing the ___ energy without affecting the equilibrium.
activation
are made up of amino acids linked together by peptide bonds. The reactant of an enzyme-catalyzed reaction is called a
substrate
The specificity of the enzyme for its substrate is known as
molecular recognition
are organic molecules commonly derived from vitamins.
coenzymes
is a substance that the body cannot normally synthesize, but it is required in small amounts for normal body function
vitamins
example of vitamins
niacin
vitamin B1
vitamin B2
vitamin B6
vitamin B12
vitamin H
vitamin K
allow reactions to occur in the body that would be impossible otherwise
enzymes
the enzyme recognizes its substrate based on its ___ and specific ____
3D shape
electrostatic interactions
enzymatic activity is always ___
stereospecific
enzyme that cleaves lactose
lactase
types of enzymes
hydrolase
lyase
ligase
transferase
isomerase
oxidoreductase
type of enzyme that catalyzes hydrolysis
hydrolase
type of enzyme that cleaves covalent bonds
lyase
enzyme that combines two molecules
ligase
enzyme that transfers functional groups
transferase
enzymes that catalyzes spatial rearrangement
isomerase
enzyme that transfers electrons from one molecule to another
oxidoreductase
Enzymes are generally very specific; they catalyze some specific chemical process; to perform their function, they often need specific substances called
cofactors
If the body does not produce this material, it must be present in the diet; these cofactors are
vitamins
The ____ site of an enzyme is generally hollow on the protein surface where the substrate can bind.
active
is generally bound to amino acids present in the binding site by a variety of interactions such as van der Waals interaction, H-bonding and ionic bonding.
substrate
what interaction can be present in enzyme-substrate complex
van der Waals interaction
H-bonding
ionic bonding
is commonly involved in enzyme-catalyzed reaction mechanisms and will form a covalent bond with the substrate as part of the reaction mechanism
what kind of amino acid
serine
is hydrolyzed by the enzyme acetylcholinesterase
what neurotransmitter
acetylcholine
are drugs that inhibit the catalytic activity of enzymes.
enzyme inhibitors
enzyme inhibitors can be classified as
competitive
non-competitive
compete with the substrate for the active site
competitive inhibitors
do not compete with the substrate to enter the active site. Instead, they bind at a different region of the enzyme and produce an induced fit, which changes the shape of the enzyme such as the active site no longer being available to the substrate. I
noncompetitive inhibitors
The binding site of the noncompetitive inhibitors is known as the
allosteric site
often present in the enzyme at the start of biosynthesis.
noncompetitive inhibitors
the inhibitor binds with the enzyme through intermolecular interactions such as H-bond, ionic bonding, and van der Waals interactions. There will be an equilibrium between the enzyme-inhibitor complex and free enzyme and unbound inhibitor
what kind of inhibitor
reversible inhibitor
the inhibitor may react with the enzyme generating a covalent bond. Such bonds are strong, and the enzyme remains permanently blocked making the inhibition irreversible.
non-reversible inhibitors
enzyme may exist in different forms having a different amino acid composition, but identical catalytic reaction
isozymes
how many vitamins are needed by the body in total
13 vitamins
two types of vitamins
water-soluble
lipid (fat)-soluble
dissolve in water and are able to roam freely in body in the blood
water-soluble vitamins
type of vitamins that is not stored in the body
water-soluble vitamins
need fat in order to be dissolved
require special carrier proteins to be transported in the blood
fat-soluble vitamins
fat soluble vitamins are stored in
fat cells
example of water-soluble vitamins
vitamin B
vitamin C
how many types of vitamin B are there
8
two main functions of vitamin B
make energy from food
make RBC
vitamin B6 and B12 deficiency can lead to
Anemia
deficiency in B1 and B3 lead to
mental confusion
most important function of vitamin C
protect the body from infection
deficency in vitamin C
scurvy
symptoms and signs can include anemia, exhaustion, spontaneous bleeding, limb pain, swelling, and sometimes ulceration of the gums and loss of teeth
scurvy
vitamin C is necessary to produce what kind of protein
collagen
main protein component of tissues
collagen
two fat soluble vitamins
Vitamin A
vitamin D
primary role is maintain and protect vision
vitamin A
protein that detects and absorb light in the eyes
vitamin A
inability to see in lowlight or darkness
Xerophthalmia
also known as sunshine vitamin
vitamin D
works to promote bone growth and bone strength
vitamin D
vitamin D deficiency
rickets or osteomalacia
active form of niacin
Nicotinamide adenine dinucleotide
is a coenzyme that is used by enzymes as an oxidizing agent for biological oxidations
Nicotinamide adenine dinucleotide
Since this is the portion of coenzyme NAD+, it is to be added to the diet so that the body can synthesize NAD+.
niacine
vitamin B2
riboflavin
riboflavin is composed of what
flavin plus ribitol
required to synthesize coenzyme flavin adenine dinucleotide (FAD)
riboflavin
an oxidizing agent in enzyme-catalyzed oxidation reactions
flavin adenine dinucleotide
used by succinate dehydrogenase to oxidize succinate to fumarate
FAD
vitamin B1
Thiamine
required to form the coenzyme thiamine pyrophosphate (TPP)
Thiamine (B1)
is required by enzymes that catalyze the transfer of two carbon fragments from one species to another
Thiamine pyrophosphate
what enzyme requires TPP for the decarboxylation of pyruvate and transfers the remaining two-carbon fragment to a proton to afford acetaldehyde
pyruvate decarboxylase
vitamin H
biotin
synthesized by bacteria that live in the intestines
vitamin H (bitoin)
does not have to be incorporated into the diet and the deficiencies are generally rare
biotin
is the coenzyme required by enzymes that catalyze the carboxylation of a carbon adjacent to a carbonyl group
biotin
The coenzyme pyridoxal phosphate (PLP) is derived from
vitamin B6
Enzymes that catalyze the reactions of amino acids require what coenzyme
pridoxal phosphate (PLP)