Unit 3 Summary 3 (My cards) Flashcards
Enzymes
Protein molecules that are the catalysts in biochemical reactions
or
Protein that catalyses (increases the rate of) chemical reactions in living organisms. An enzyme is specific for a particular chemical reaction and may be used over and over again
Catalyst
Chemical substances that speed up reactions without being used up themselves, they do so by lowering activation energy by providing an alternative reaction pathway. they bind to reactants and weaken their chemical bonds
Substrate
Chemical substances that speed up reactions without being used up themselves, they do so by lowering activation energy by providing an alternative reaction pathway. they bind to reactants and weaken their chemical bonds
Enzyme-substrate complex
The intermediate formed when a substrate molecule interacts with the active site of an enzyme.
Active site
Region of an enzyme where a substrate binds and catalysis takes place
Activation energy
The energy barrier that must be reached in order for a chemical reaction to begin
Enzyme naming
-ase
Affinity
Attraction of enzyme and substrate to each other
Measure of the ease with which an enzyme binds with its substrate
Lock and key model
Exact fit of substrate to active site
Induced fit hypothesis
Shape of active site changes when it binds to substrate
Biochemical pathway
When substrate is converted into product by the first enzyme in the pathway and the product of the first reaction then becomes the substrate for the next reaction etc etc until the initial substrate is converted into the final product through the series of steps of the pathway.
Anabolism
Buildup/endergonic/endothermic
Anabolic reactions involve the building up of larger molecules from small ones (they are endergonic); e.g. protein synthesis
Catabolism
break down (Sometimes cats make me break down)/exergonic/exothermic Catabolic reactions involve the breakdown of molecules into smaller molecules (they are exergonic); e.g. digestion
Endergonic
Requires energy
Endergonic reactions absorb energy overall.
Exergonic
Releases energy
Exergonic reactions have an overall release of energy.
