Read the below statements about enzymes and choose the correct option: 1. Enzymes increase the activation energy of a reaction. Which of the above statements are correct?
2. Enzymes are specific to substrates due to active site configuration.
3. Enzyme activity is affected by pH and temperature.
Only 2 and 3 are correct
Statement 1: Incorrect. Enzymes lower the activation energy of a reaction, providing an alternative pathway with a lower energy barrier and thereby speeding up the reaction.
Statement 2: Correct. Each enzyme has a specifically shaped active site that fits only certain substrates (the lock-and-key / induced-fit model). This is why an enzyme typically catalyses one reaction or a small group of related reactions.
Statement 3: Correct. Enzyme activity peaks at an optimum pH and temperature; outside that range, the protein denatures or its ionisation state changes, reducing or stopping activity.
Hence only statements 2 and 3 are correct.
Identify the animal that does NOT have bilateral symmetry.
Which of the following statements is FALSE?
What happens to the guard cells when water flows into them?
Colloidal systems – such as gum, starch, proteins, cellulose, agar, and gelatine – when placed in water, will absorb a large volume of water and swell up. These substances are called _________.
_______ is a branch of biology that studies fungi.
Which of the following is a natural flame retardant?
Which component performs the task of capturing oxygen in the blood?
Select the correct option about Kwashiorkor.
Statement A: It is a form of malnutrition caused by a lack of fat in the diet.
Statement B: Children who develop Kwashiorkor may not grow or develop properly and may remain stunted for the rest of their lives.
Match the columns.
Column-A (Enzyme/Protein) | Column-B (Role in DNA replication) | ||
i. | Helicase | a. | Joins the 3' end of the new DNA fragment to the 5' end of the previous one |
ii. | RNA primase | b. | Nucleotide polymerisation |
iii. | DNA polymerase | c. | RNA primer synthesis |
iv. | DNA ligase | d. | Opens up the DNA double helix |
Which cells, also called neurilemma cells, are the main glial cells in the PNS and play an essential role in the survival and functions of neurons?
Which of the following statements about living and non-living being is/are correct?
1. While living being can demonstrate growth and repair, non-living being cannot.
2. While living being demonstrates metabolic processes, non-living being does not.
Movement of materials to different parts of cytoplasm and nucleus is generally carried out by
Which one of the following cell organelles may play a role in expelling excess water and wastes in case of unicellular organisms?
Transformation of meristematic cells into specific permanent tissues occurs by the process of
If human blood is placed in a 2% detergent solution, what will happen to the RBC?