3 enzymes Flashcards
define enzymes
enzymes are the most important group of proteins which are biologically active
active site
the catalytic activity of an enzyme is restricted to a small portion of the structure of enzyme called active site.
it consist of few amino acids ,while the rest of the bulk of the amino acids maintains the globular structure of enzyme.
substrate
the substance which react with enzyme is called substrate.
substrate attach to the active site of the enzyme which is composed of only few amino acids , while the rest of the bulk of amino acids maintain the globular structure of protein
co.factor
some enzymes also have the non protein part known as co factor .
co factor is essential for the proper functioning of enzyme.
acts as a bridge between enzyme and substrate
sometimes co factor provides the activation energy requires to derive the chemical reaction which would be impossible or difficult other wise.
types of co factors
activator [detachable]
prosthetic group [ covalent bond ]
co enzyme [loosely bonded]
example of activator
mg 2 [p],
fe 2 [p],
cu 2 [p]
zn 2 [p]
example of prosthetic group
FAD[ falvin adenine dinucleotide ]
FMN [Falvin mono nucleotide]
example of co enzyme
NAD [p] nicotimamide adenine dinucleotide
NADP[P] nicotinamide denine dinunleotide phosphate
activator
the non protein part which detaches from the protein part after the completion of its function is called activator
OR
the detachable co factor is called activator
some enzymes use metal ions as co factor is known as activator if it is an inorganic ion
prosthetic group
when non protein part is covalently bonded to the enzyme that part is known as prosthetic group.
co enzyme
when non protein part is loosely attached to the protein part of the enzyme then it is called co enzyme .
many are vitamins or derivatives of vitamins
apoenzyme
enzyme without protein part is called apoenzyme
it is an inactive form of enzyme
holoenzyme
complete enzyme with a co factor is called holo enzyme
it is the active form of enzyme.
enzyme distribution in cell
dissolve in the cytoplasm
some are tightly bound to organelles
in chloroplast
in mitochondria [kreb cycle ]
ribosome
characteristics of enzymes
1 globular protein
2 increase the rate of reaction
3 does not effect the nature of product
4 small amount can bring a large amount of change
5 highly specific in action
6 sensitive to ph ,tem
7 some require co factor
8 lower the activation energy
9can be inhibited
10 obtain at the end remain unreacted
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