Match the choice on the left with the correct choice on the right. double-reciprocal feedback inhibition covalent modification proteolytic cleavage ribozymes prosthetic group induced-fit model
a. zinc
b. rna
c. protein kinases do. lineweaver—burk plot
e. end-product inhibition f. distortion of substrate and enzyme g. trypsin

1. Double-reciprocal pairs with d. Lineweaver-Burk plot. A double-reciprocal plot, also known as Lineweaver-Burk plot, is a biochemical term which refers to the graphical representation of enzyme kinetics. It is used to calculate important terms of enzymatic kinetics, such as Vmax (the maximum reaction velocity) and Km (the Michaelis-Menten constant).

2. Feedback inhibition pairs with e. end-product inhibition. Feedback inhibition is again an important term of Biochemistry. The term describes the process by which the action of an enzyme is blocked by the product of the enzyme's action. More specifically, an enzyme catalyzes a reaction and as a result, a product is formed. When the product reaches the desired concentration, the product acts on the enzyme and inhibits its action. 

3. Covalent modification pairs with protein kinases.Covalent modification is a term which describes the modification of an enzyme as an effort to regulate its activity. The most common covalent modification is the phosphorylation, which is a reaction catalyzed by protein kinases. Phosphorylation is a reversible modification and consists of the transfer of phosphoryl groups to organic molecules.

4. Proteolytic cleavage pairs with trypsin.The term proteolytic cleavage describes the process of breaking the peptide bonds between amino acids in proteins. This process is achieved through the action of specialized enzymes called proteases or peptidases. Proteases are enzymes that break down proteins into smaller molecules, a process called proteolysis. Trypsin is a protease which breaks down proteins by adding water molecules (hydrolysis) and is found in the digestive system.

5. Ribozymes pairs with b. RNA
Ribozymes, also known as ribonucleic acid enzymes, are RNA molecules which are capable of enzymatic action. They are characteristic for their double nature, they are genetic material and they catalyze biochemical reactions. Their most common actions are to cleave RNA and DNA molecules and to form bonds between peptides. 
6. Prosthetic group pairs with zinc.There are some enzymes which need the presence of other enzymes or molecules in order to get activated. There are three types of molecules which can help the action of an enzyme; the cofactors, the coenzyme and the prosthetic groups. A prosthetic group is a molecule which increases the rate of the enzymatic reaction (cofactors) and is tightly bound to the enzyme. Metal ions, such as zinc, are common prosthetic groups.

7. Induced-fit model pairs with distortion of substrate and enzymeTwo theories have been proposed as to how enzymes bind to the substrate and catalyze a reaction. One of them is the lock-and-key model and the other one is the induced-fit model (which is the more widely accepted). According to the induced-fit model, the shape of the enzyme changes in accordance to the substrate. On the contrary, the lock-and-key model suggests that the active site of the enzyme and the substrate are exact matches.