Enzymes Flashcards
What are enzymes ?
They are proteins which reduce the activation energy and increase the rate of reaction without being consumed .
They also don’t change free energy realised or required
Enzymes required for most biological reactions .
They control reaction of life.
Highly specific
What happens without enzymes ?
Metabolic /signalling reactions would be slow
What are some key features /Properties of enzymes ?
Reaction specific :
Each enzyme works with a specific subreate chemical fits because active site/subrate by hydrogen bonds /ionic bonds.
Enzymes themselves are not consumed in the reaction , but a single enzyme molecule can catalyse a thousands or more reactions per second
Enzymes are unaffected by the reaction .
Affected by cellular conditions any conditions that affect proteins structures including temperature .
How does Temperature affect enzyme ?
At a optimum temperature , more kinetic energy of enzymes , substrate increases causing more collisions between the enzyme /substrate .
An increase in temperature beyond the optimum level causes the enzymes active site to be denatured .Meaning it looses its important shape/no longer forms enzymes substrate complex leading to a decrease in enzyme activity .
pH is another factor how does that affect the enzyme ?
Causes the enzyme active site to become denatured loosing its important shape .Adding /removing h+ disrupts bonds as well as 3D shape
Disrupts attraction between charged amino acids affecting 2 and 3 structure
Pepsin is an enzyme found in stomach degrades food proteins into peptides .
Trypsin found in pancreas and in small intestines and works in a neutral environment .pH 8
Whereas, pepsin works in an acidic environment in the stomach of pH 2-3 .
How can enzyme concentration affect the enzyme ?
Affect the enzyme concentration
The higher the enzyme concentration the more enzymes there are to form enzyme substrate complexes Leading to an increase in enzyme activity .
Towards, the end substrate becomes a limiting factor as not all enzymes molecules can find a substrate .
How does the Salinity affect the enzyme concentration ?
Changes in the salt concentration can affect the enzyme function .
Due to the removal of cations /anions which can affect the secondary and tertiary structure
Increasing the salinity means increasing the amount of ions in a solution .These ions could disrupt the electrostatic interaction between amino acids which hold the tertiary structure together .
If the salinity is too high/low the interaction between side chains /charged groups are blocked causing enzymes to change shape.
Extreme salinity can cause the enzyme to denature and no longer function
How can hot and cold and heat affect enzymes ?
This part comes under temperature
Heat can disrupt bonds between enzyme/substrate causing it too loose 3D shape/tertiary structure .
Cold temperature , temperatures decrease with the molecules moving slower , decreasing collisions between enzyme/substrate .
What are the compounds which help enzymes ?
Coefactors:
Non -proteins , small inorganic
Compounds and ions
Mg, K, Ca, Zn, Fe, Cu
Bound within enzymes molecules
Coe enzymes :
Non-protein ,organic molecules
Bind temporality/permanently to enzymes near active .
Many vitamins
NAD(niacin B3)
FAD(Riboflavin;B2)
Coeenzyme A
What is excergonic reaction ?
Energy is released from the surroundings , the bonds being formed are stronger than the bonds being formed .
Energy is released known as Gibbs energy.
Energy is digested
Energy of reactant greater than products
Spontaneity of reactions , a reaction is feasible reactions will happen.
Run from left to right
Negative because the reaction looses
Catabolism : Breaking down/Atp is released
Refer to changes in enthalpy . As well as refers to changes in the Gibbs free energy ability to do work .
What is the Endergonic Reaction ?
Energy is absorbed to the surroundings
The bonds being formed are weaker than the bonds being broken .
Building polymers, more organisation higher energy state .
Positive energy must be supplied .
Refer to changes in the enthalpy . As well as changes in Gibbs free energy
Anabolism building up
Reaction use up energy
