Chapter 3: Internal Membranes and Enzymes Flashcards
What is the mitochondrial mix?
The gel-like substance enclosed by the inner membrane of a mitochondrion
What is the purpose of the mitochondrial mix?
Contains enzymes in solution that are responsible for reactions in another stage of cellular respiration
What are catalysts?
A substance that speeds up a chemical reaction without being used up in the reaction
Why are enzymes called the organic catalysts?
They act as catalysts and speed up the reactions within a cell
What is cellular metabolism?
All of the chemical processes occurring in a living cell
What are intracellular enzymes?
An enzyme that functions inside the cell that produces it, to speed up and control metabolic reactions
What are extracellular enzymes?
An enzyme that is produced by cells but functions outside of the cells. E.g. digestive enzymes that break down food
What is activation energy?
The energy required to initiate a reaction
What are biochemical pathways?
Chemical reactions in cells that occur in a series of enzyme-regulated steps
What is a substrate?
A substance that enters a reaction, also called reactant or precursor
What is an enzyme-substrate complex?
A substance formed when an enzyme and a substrate molecule join
What is an activation site?
The place on the surface of an enzyme molecule where substrate molecules attach
What is the lock-and-key model?
A model suggesting that the shape of a substrate molecule is an exact fir to the shape of an enzyme’s active site
What is the induced-fit model?
A model to explain that the shape of an enzyme’s activation site undergoes specific changes, induced by the substrate to achieve a high degree of specificity with the substrate
What is one of the fastest acting enzymes?
Catalase
Do enzymes reduce or increase activation anergy?
Reduce
What are equilibrium reactions?
A chemical reaction in which the forward and reverse reactions occur at equal rates
What are enzymes sensitive to?
Change in temperature, pH, substrate and product concentrations
What temperatures do enzymes have an optimal range at?
The temperature of the environment they are found in
What are psychrophiles?
An organism that can grow and reproduce at low temperatures, ranging from -20ºC to 10º C
What is denaturation?
The process by which the structure of a protein is changed by factors such as pH and temperature, the change in structure often destroys the shape of the active site of the molecule and results in a loss of function
What is the optimal pH for an enzyme?
The pH of the environment it is found in
What is a non-competitive inhibitor?
A molecule that binds to an enzyme at a site other than the active site, this changes the shape of the enzyme so that the substrate can no longer bing to the active site
What is a competitive inhibitor?
A substance that competes with a substrate for an enzyme’s active site
What are cofactors?
A small inorganic substance that is required in addition to an enzyme to catalyse a certain reaction
What are coenzymes?
A small non-protein organic substance that is required in addition to an enzyme to catalyse a certain reaction
