Medical Biochemistry: Enzymes Chemistry

Oxidoreductases catalyze the reactions of oxidation and ______

The mechanism of oxidation is either by removal of hydrogen (dehydrogenases) or by addition of ______

Transferases catalyze the transfer of groups other than hydrogen from one substrate to another. They are further classified according to the group they transfer e.g. phosphotransferases (kinases), transaminases, transketolases, ______

Isomerases catalyze the ______ reactions

The ______ group of enzymes catalyze the reactions of oxidation and reduction

Enzymes are powerful and highly specific biological catalysts (The difference between ______ and un______ reactions_

General properties of enzymes 1. They are mostly protein in nature. NOT ALL enzymes are protein but there are some ribozymes (rRNA in nature) 2. They act within a moderate pH and temperature range. 3. They are highly specific that catalyze only one type of chemical reaction.

There are different types of specificity:  Optical specificity (stereospecificity): Enzymes act only one of 2 ______ e.g. maltase acts on α-glycosides but not β-glycosides.

There are different types of specificity:  Group specificity: Enzymes act on a specific group or linkage e.g. pepsin acts on peptide bonds.  Absolute specificity: Enzyme acts only one ______ e.g. urease enzyme acts on urea.

General properties of enzymes Enzymes Extra______ular Intra______ular They are secreted from the They are formed inside the ______ where they function. As, ______ where they function.

Enzyme Classification

Oxidoreductases are enzymes that catalyze oxidation and reduction reactions.
The oxidation mechanism involves either the removal of hydrogen or the addition of oxygen.
Transferases facilitate the transfer of various functional groups (excluding hydrogen) between substrates.
Types of transferases include phosphotransferases (kinases), transaminases, and transketolases.
Isomerases catalyze structural changes within molecules, facilitating isomerization reactions.

General Properties of Enzymes

Enzymes are primarily proteins, though some (ribozymes) are made of ribonucleic acid (rRNA).
They operate effectively within specific temperature and pH ranges.
Enzymes are highly specific, each catalyzing a particular type of chemical reaction.
Optical specificity refers to the ability of enzymes to act on one of two stereoisomers; for example, maltase specifically catalyzes α-glycosides, not β-glycosides.
Group specificity denotes the action of enzymes on specific functional groups, such as pepsin which targets peptide bonds.
Absolute specificity means an enzyme acts on a single substrate only, exemplified by urease, which specifically acts on urea.

Cellular Locations of Enzymes

Extracellular enzymes are secreted from cells and function outside of them.
Intracellular enzymes are produced and operate within the cells where they were formed.

Test your knowledge of enzymes' powerful and highly specific biological catalysts in medical biochemistry. Explore the differences between catalyzed and uncatalyzed reactions, and learn about the general properties of enzymes, including their mostly protein nature.