enzymes Flashcards
what are enzymes made of
-large globular proteins
when is energy released
-when large molecules undergo catabolic reactions in metabolic pathways
what is the matabolism
-the sum of all the different anabolic and catabolic reactions and reaction pathways in a cell/organism as a result of enzymes
what type of reactions do enzymes catalyse
-anabolic
-catabolic
examples of anabolic reactions
-triglyceride synthesis
-protein synthesis
-photosynthesis
examples of catabolic reactions
-respiration
-glycolysis
-lipolysis
-hydrolysis of ATP
-breakdown of polysaccharides like starch and glycogen into monosaccharides like glucose
example of reaction that would not happen without an enzyme
-DNA replication, photosynthesis
demo of temperature on enzymes
-Liver demo
describe the liver demo
-in mammals, catalase is an intracellular enzyme produced primarily in the liver
-it breaks down toxic build up of hydrogen peroxide
-when liver is boiled and then laced into hydrogen peroxide, doesn’t react as the enzyme catalase has been denatured, it cant break down hydrogen peroxide into water and oxygen
what are reactants in an intracellular enzyme known as
-metabolites
catabolic vs anabolic
-catabolic breaks down
-anabolic synthesises larger molecules
facts abt enzymes
-more specific than chemical catalysts
-don’t produce unwanted by products
-rarely make mistakes
ways to increase rate of reaction
-increase pressure, temp, surface area, concentration
-use enzyme to lower activation energy
example of a reaction that doesnt require enzymes
-peptide bond hydrolysis would happen anyway without an enzyme
active site of an enzyme
-highly specific
-complementary to the shape of the corresponding substrate molecule
what are the stages of enzymes
-enzyme + substrate
-enzyme substrate complex
-enzyme product complex
-enzyme + products
how does the lock and key model work
-the substrate is held in a fixed position (causing R groups to interact) which pouts the atom groups close enough to react
-the R-groups in the active site interact with the substrate forming temporary bonds
-these bonds put strain on the substrate
how does the induced fit model work
-initial weak interactions between the substrate and active site changes the tertiary structure of the enzyme, putting strain on the bonds in the substrate molecule
-the weakened bonds in the substrate are more likely to break causing a reaction to happen
in the lock and key model what puts strain on the substrate
the position the substrate is held in
in the induced fit model what puts strain on the substrate
-bonds formed as the substrate is approaching the active site
what do bonds form between when the substrate binds to an enzyme?
-the substrate and the amino acids on surface of active site (R- Groups)
what made scientists previously think the lock and key model was how enzymes worked?
-they thought the tertiary structure was fixed and the substrate slotted perfectly into it
why wasn’t the lock and key model correct?
- as the substrate approaches and starts to form bonds w AA’s the tertiary structure of the active site changes and moulds to fit the substrate
why can different substrates not bond to an enzyme
-they cant form the correct bonds w the AA’s on the active site and tertiary structure doesn’t change to fit it
