Enzymes
Enzymes: Overview
This topic covers concepts, such as, Enzymes, Nomenclature of Enzymes, Ribozyme & Chemical Reactions etc.
Important Questions on Enzymes
Study the given data and answer the following question.
A sample of an enzyme called lactase was isolated from the intestinal lining of a calf. Assays were undertaken to evaluate the activity of the enzyme sample. The substrate of lactase is the disaccharide lactose. Lactase breaks a lactose molecule in two, producing a glucose molecule and a galactose molecule.
Two assays were carried out.
Assay 1:
| Lactose concentration (% w/v) | 15 | 15 | 15 | 15 | 15 | 15 |
| Concentration of enzyme sample (% v/v) | 0 | 5 | 10 | 15 | 20 | 25 |
| Reaction rate glucose sec-1 mL-1 | 0 | 25 | 50 | 75 | 100 | 125 |
Assay 2:
| Lactose concentration (% w/v) | 0 | 5 | 15 | 20 | 25 | 30 |
| Concentration of enzyme sample (% v/v) | 5 | 5 | 5 | 5 | 5 | 5 |
| Reaction rate glucose sec-1 mL-1 | 0 | 15 | 25 | 35 | 40 | 40 |
Which of the following statements can be concluded from the two assays?
Select the correct option:
Assertion: All proteinaceous enzymes have a three-dimensional structure.
Reason: The secondary structure of a protein is according to amino acids present inside the polypeptide.
Dehydrogenase are mainly responsible for oxidation of its substrates whereas reductase are mainly responsible for reduction of its substrates.
Dehydrogenases catalyze the _____ reaction with the help coenzyme such as NAD+/NADP+ or flavin such as FAD.
Which of the following represents the functions performed by cells?
The breakdown of molecules to obtain energy is called _____.
Explain about the chemical reactions happening in living organisms.
Denaturation of the enzyme is an example of reversible inhibition.
Fill in the blank with the correct answer from the bracket.
_____ inhibition is caused by alteration of confirmation of the enzyme by a chemical that binds to a site other than the active site. (Competitive, Noncompetitive, Reversible)
The enzyme DNA ligase is also known as molecular scissor.
The conversion from glucose-6-phosphate to fructose-6-phosphate is catalysed by the enzyme of group isomerase.
Isomerases catalyse the oxidoreduction between two substrates.
Which group of enzymes catalyses reactions involving a structural rearrangement of a molecule?
