Enzymes Flashcards
Enzymes in Chemical Reactions
Enzymes are catalysts of chemical reactions in cells and are necessary in all cell chemical reactions.
Enzymes and Activation Energy
Enzymes lower the amount of energy needed for the chemical reaction– they lower energy of activation.
Lock And Key model
Enzymes are highly specific to a certain substrate. Only lactase can break down lactose for example, sucrase cannot perform this function. A specific substrate is the lock, the specific enzyme is the key that can only fit this specific lock.
Substrate
What is being altered in a chemical reaction, what the enzyme is acting upon
Active Site
Where The substrate binds on the enzyme
Enzyme-Substrate Complex
A temporary molecule that forms when a substrate and enzyme make perfect contact. It causes a shape change which can force two molecules together or split molecules into smaller parts. Once the substrate is changed it can no longer bind to the enzyme, and a new substrate will bind.
The enzyme-substrate complex reduces…
reduces the amount of energy needed for chemical reactions to occur, making the process faster
Cofactors + examples
Cofactors are non-protein chemical compounds (often minerals) that certain enzymes need to function as catalysts. EX: DNA Polymerase requires a 2+ charge cation magnesium to function because nucleotides are negatively charged they attract eachother
Coenzyme
Coenzymes are non-protein organic compounds (often synthesized from vitamins) that some enzymes need to function as catalysts.
Biochemical Pathway
Biochemical reactions that happen one after another that leads to a certain product or change in the cell.
Negative Feedback Loop in Biochemical Pathways
When a product of a biochemical pathway inhibits a previous enzyme in a pathway. This happens because there is enough product, which saves energy and manages resources.
Denature Definition
Enzymes are broken apart and return to being singular, unbonded amino acids. This happens in certain environmental conditions such as suboptimal pH or Temperature (which differs between enzymes, but most prefer moderate conditions)
How Substrate Concentration influences enzyme reactions
The rate of enzymatic reaction increases with an increased level of substrates, until the point of saturation is reached. At this point, so much substrate is present that all enzyme active sites are inhabited, meaning that the excess substrates have nowhere to bind.
How Enzyme Concentration affects enzyme reactions
When the enzyme concentration is significantly lower than substrate concentration, less reactions take place. The reaction rate increases as the concentration of the enzyme increases.
Competitive Inhibition
Inhibitors bind to active site of enzyme before the substrate, blocking the ability for chemical reactions to take place. Must have a higher concentration of inhibitors than substrates for effect.
