Tag: enzymes

A competitive inhibitor is a reversible inhibition where the inhibitor competes with the substrate for the active site of an enzyme. While the inhibitor occupies the active site it prevents binding of the substrate to the enzyme. Many competitive inhibitors are compounds that resemble the substrate and combine with the enzyme to form an enzyme inhibitor complex, but without leading to catalysis. Even fleeting combinations of this type will reduce the efficiency of the enzyme. By taking into account the molecular geometry of inhibitors that resemble the substrate, we can reach conclusions about which parts of the normal substrate bind to the enzyme. Competitive inhibition can be analyzed quantitatively by steady-state kinetics.

Competitive inhibitors of enzymes compete with the active site of enzyme making them unavailable for the originally desired substrate. 

Succinate was placed in one of the most important cyclic pathways in metabolism, a collecting pool of catabolic and a starting point of many anabolic processes. Succinate is a product of substrate-level phosphorylation materialized in the citric acid cycle. It is involved in a macrophage-specific metabolic pathway generating and is also a downstream product of the α-ketoglutarate dehydrogenase complex, a heavily regulated multi-subunit complex.

The vitamins act as part of coenzymes, small molecules that combine with an enzyme to make it active.

Enzymes are biocatalyst. These are proteinaceous substances that are capable of catalysing chemical reactions of biological systems without themselves undergoing any change. The term enzymes were first used by Kuhne in 1877.

Amylase is a protein-based enzyme that is secreted by the salivary glands of mouth and is involved in the breakdown of starch. It functions in a neutral pH (pH 7). Renin is also a protein enzyme secreted in the stomach and involved in the coagulation of milk. It functions in a acidic pH. Trypsin is also a protein enzyme that is produced in the small intestine and is a proteolytic enzyme. It also functions in acidic pH. So, the correct answer is 'These are all proteins'.

The activity of an enzyme can be affected by a change in the conditions which can alter the tertiary structure of the protein. These include temperature, pH, change in substrate concentration or binding of specific chemicals that regulate its activity. Enzymes generally function in a narrow range of temperature and pH. Each enzyme shows its highest activity at a particular temperature and pH called the optimum temperature and optimum pH. Activity declines both below and above the optimum value. Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat. At boiling temperature all proteins including enzymes are denatured.

All proteins are not enzymes. Proteins are most versatile biochemicals fulfilling a diverse set of structural and functional roles. For example, haemoglobin, keratin, albumin, etc., are all proteins but are not enzymes. Similarly, all enzymes are not proteins. In fact, most of the enzymes, are proteinaceous in nature. But ribozymes are not proteins in nature, they are catalytic RNAs.

Enzymes are the specialized proteins which are capable of catalyzing reactions in the living cells.