F4 B5 ENZYME Flashcards
What is the meaning of metabolism?
- all chemical reactions that occur in a living organisms
What are the 2 types of metabolism? Explain
- Catabolism
- Process of breaking down complex substance into simple substances
- Anabolism
- Process of synthesising complex molecule from simple molecule.
What are enzymes?
- organic catalyst made up if proteins
- produced by living cell organisms
What substances is needed for an enzyme reaction?
- substrates
What are the general characteristics of enzymes?`
- act rapidly
- only required in small quantities, are reusable
- structure remain unchanged after a reaction
- reaction are specific
- most reactions are reversible
- enzymes activities can be slow down by enzyme inhibitors
- some need cofactors to work efficiently
- some are biochemical catalysts that speed up biochemical reactions.
What is the definition of intracellular enzymes?
enzymes that are synthesized in a cell for its own use
What is extracellular enzymes?
enzymes that are secreted outside the cell
How are extracellular enzymes produced?
- ribosome synthesise protein
- protein enter lumen of RER and are transported through it
- reaches the end, membrane buds off to form transport vesicle
- transport vesicle moves to golgi apparatus and fuses with it
- in GA, proteins are modified into enzymes and secreted in secretory vesicle formed from tip of GA
- secretory vesicle move towards plasma membrane and fuse with it
- secrete extracellular enzymes
What is the mechanism of enzyme reactions?
the lock and key hypothesis
Explain the lock and key hypothesis?
- specific substrate approaches the enzyme
- substrate combines with active site to form enzyme-substrate complex
- a reaction occurs, a product created, product leaves active site
What is activation energy?
energy needed to break the bond in the substrate molecule before reaction can occur
Whats the optimal temperature of enzyme?
37 *c
Whats the optimal pH for enzyme to react most effectively?
between pH 6 and 8
