Enzymes Flashcards
What are enzymes?
Large, globular proteins which act as Catalysts in metabolism
What 2 theories are used to explain how enzymes work?
Lock and key
Induced fit
What does induced fit suggest about the active site of an enzymes?
The active site alters its shape to be complement to the substrate
What is an enzyme substrate complex?
When the tertiary structure of the active site successfully binds to the substrate
How many reactions can an enzyme catalise and why?
Many as they are not permenantly damaged
What are intracellular enzymes? Give an example
Enzymes that work inside cells.
Catalase breaks down into hydrogen peroxide and water in the liver
What are extra cellular enzymes? Give an example
Enzymes that work outside of cells.
Trypsin breaks down proteins in the small intestine
How does temperature effect enzyme reactivity?
Enzymes and substrates gain kinetic energy and so collide more creating more enzyme substrate complexes
What happens if the temperature is above optimum on enzymes?
The enzymes tertiary structure denatures
What is the temperature coefficient and what is the equation?
The increase in rate of reaction as a result of increasing the temperature by 10 degrees celsius.
Q10 = R2 ÷ R1
What graph shape is made during enzyme reactions?
Bell curve
Describe the effect of PH on enzyme reactivity
Any movement away from optimum PH causes their to be an unbalanced level of H+ ions which causes the tertiary structure of the active site to denature
What is the PH of HCl
1 or 2
What does pepsin break down?
Large proteins in the stomach
What does pancreatic juice contain?
Trypsin madd in the gall bladder is alkali of 7.8
What is a limiting factor?
Something which prevents a reaction from continuing
What does inhibition mean?
Stop / prevent
What does inhibition mean?
Stop / prevent
What is a competitive inhibitor?
Something that is also complementary to the active site but is not the substrate. They slow reactions but eventually reach v-max
What is a non competitive inhibitor?
Something which binds to an alloseric site on the enzyme altering the shape of the active site so it is no longer complementary to the substrate. Doesn’t reach v-max
What is end product inhibition?
When the product can stop or enhance production based on how much has already been produced
What is a cofactor, coenzyme and prosthetic group?
Cofactor: inorganic protein bound to substrate
Coenzyme: organic protein bound to substrate
Prosthetic group: can be co factors or co enzymes
What is a holoenzyme?
An enzyme containing a co factor or co enzymes
What is a holoenzyme?
An enzyme containing a co factor or co enzymes
