Chapter 16 Chemistry in Everyday Life Solutions
Question - 11 : - Which forces are involved in holding the drugs to theactive site of enzymes?
Answer - 11 : -
Either of the following forces can be involved in holdingdrugs to the active sites of enzymes.
(i) Ionic bonding
(ii) Hydrogen bonding
(iii) Dipole − dipole interaction
(iv) van der Waals force
Question - 12 : - While antacids and antiallergic drugs interfere with thefunction of histamines, why do these not interfere with the function of eachother?
Answer - 12 : -
Specific drugs affect particular receptors. Antacids andanti-allergic drugs work on different receptors. This is the reason whyantacids and anti-allergic drugs do not interfere with each other’s functions,but interfere with the functions of histamines.
Question - 13 : - Low level of noradrenaline is the cause of depression.What types of drugs are needed to cure this problem? Name two drugs.
Answer - 13 : -
Anti-depressant drugs are needed to counteract the effectof depression. These drugs inhibit enzymes catalysing the degradation of theneurotransmitter, noradrenaline. As a result, the important neurotransmitter isslowly metabolised and then it can activate its receptor for longer periods oftime.
Two anti-depressant drugs are:
(i) Iproniazid
(ii) Phenelzine
Question - 14 : - What is meant by the term ‘broad spectrum antibiotics’?Explain.
Answer - 14 : -
Antibiotics that are effective against a wide range ofgram-positive and gram-negative bacteria are known as broad spectrumantibiotics. Chloramphenicol is a broad spectrum antibiotic.
It can be used for the treatment of typhoid, dysentery,acute fever, pneumonia, meningitis, and certain forms of urinary infections.Two other broad spectrum antibiotics are vancomycin and ofloxacin. Ampicillinand amoxicillin −synthetically modified from penicillin − are also broadspectrum antibiotics.
Question - 15 : - How do antiseptics differ from disinfectants? Give oneexample of each.
Answer - 15 : -
Antiseptics and disinfectants are effective againstmicro-organisms. However, antiseptics are applied to the living tissues such aswounds, cuts, ulcers, and diseased skin surfaces, while disinfectants areapplied to inanimate objects such as floors, drainage system, instruments, etc.Disinfectants are harmful to the living tissues.
Iodine is an example of a strong antiseptic. Tinctureof iodine (2 − 3 percent of solution of iodine in alcohol − water mixture) isapplied to wounds. 1 percent solution of phenol is used as a disinfectant.
Question - 16 : - Why are cimetidine and ranitidine better antacids thansodium hydrogen carbonate or magnesium or aluminium hydroxide?
Answer - 16 : -
Antacids such as sodium hydrogen carbonate, magnesiumhydroxide, and aluminium hydroxide work by neutralising the excess hydrochloricacid present in the stomach. However, the root cause for the release of excessacid remains untreated.
Cimetidine and rantidine are better antacids as theycontrol the root cause of acidity. These drugs prevent the interaction ofhistamine with the receptors present in the stomach walls. Consequently, thereis a decrease in the amount of acid released by the stomach. This is whycimetidine and rantidine are better antacids than sodium hydrogen carbonate,magnesium hydroxide, and aluminium hydroxide.
Question - 17 : - Name a substance which can be used as an antiseptic aswell as disinfectant.
Answer - 17 : -
Phenol can be used as an antiseptic as well as adisinfectant. 0.2 percent solution of phenol is used as an antiseptic, while 1per cent of its solution is used as a disinfectant.
Question - 18 : - What are the main constituents of dettol?
Answer - 18 : -
The main constituents of dettol are chloroxylenol andα-terpineol.
Question - 19 : - What is tincture of iodine? What is its use?
Answer - 19 : -
Tincture of iodine is a 2 − 3 percent solution of iodinein alcohol − water mixture. It is applied to wounds as an antiseptic.
Question - 20 : - What are food preservatives?
Answer - 20 : -
Food preservatives are chemicals thatprevent food from spoilage due to microbial growth. Table salt, sugar,vegetable oil, sodium benzoate (C6H3COONa),and salts of propanoic acid are some examples of food preservatives.