1What are enzymes?
Tertiary structure proteins
Are a very specific 3D shape
2What are enzymes held together by?
Peptide, hydrogen, ionic and disulphide bonds
3Describe the lock and key theory
Successful collison, substrate fits exactly into AS
Form enzyme-substrate complex
Reaction happens->products formed and AS is unchanged
4Describe the induced fit theory
AS and enzyme arent fully complementary
Substrate forces way into AS
Both change shape slightly
Bonds in substrate weaken and reaction occurs at lower activation energy
5What other enzyme uses the induced fit theory to function?
Lysosome
6What are intracellular enzymes?
Enzymes that work inside cells/are attached to a membrane
7What are extra cellular enzymes?
Secreted, Outside the cell, eg. Amylase, saprophylic fungi and bacteria
8What are competitive inhibitors?
Complementary in shape to the AS
Enters into AS, blocks it
Prevent formation of enzyme-substrate complex
Not perma bonded
9What are non-competitive inhibitors?
Bind to enzyme at allosteric site
Alters shape of active site, no enzyme-substrate complexes can form
Some perma bond, some don’t
10How can the effect of the competitive inhibitor be decreased?
If the concentration of substrate is increased, substrate will collide with AS more often than inhibitor
11How are enzymes catalysts?
They lower the activation energy and stay unchanged after the reaction
12How does temperature affect enzymes?
Low temp->less kinetic energy->few successful collisions
As temp increases->more kinetic energy->more collisions (continues until the optimum temp reached)
13How does substrate concentration affect enzymes?
Reaction relies on collisions, conc of substrate limits ror, conc of substrate increases, not enough AS so enzyme conc limits ror.
14At what temp do enzymes denature at?
60°
15What type of enzyme has an optimum temp of 85°?
Some thermophilic bacteria
16How does pH affect enzymes?
Affects formation of hydrogen and ionic bonds
Enzyme tertiary structure altered by levels above/ below pH 7
Denatures enzyme
17How does enzyme concentration affect reaction?
Increase in enzyme conc increases ror
18What are immobilised enzymes used for?
Biosensors
Creating lactose-free milk
19What are the adv of immobilised enzymes?
Increased stability, denatures at higher temp and wider range of pH
Products are uncontaminated
Enzymes can be reused
Enzymes can be easily added and removed
20What does denatured mean?
Enzyme AS is perma changed
21What does inactivation mean?
Reversible reduction of enzyme activity at low temps, molecules dont have enough kinetic energy to work
22What is activation energy?
Energy needed to start a reaction
23How do you work out rate of reaction?
change/time=ror
24What four things affect the ror of an enzyme controlled reaction?
Substrate conc
Temp
pH
Enzyme conc
25What are anabolic reactions?
Build up molecules
26What are catabolic reactions?
Breaking down molecules
27What is a metabolism?
Combo of anabolic and catabolic reactions, all reactions in body
28What is a catalyst?
Speeds up ror
29What is a metabolic pathway?
Sequence of enzyme controlled reactions
30What is specifity?
Only able to catalyse specific reactions
31What is substrate?
Molecule that the enzyme works on
32What is product?
Molecules produced by enzymes