Matric Notes Biology Class 10th Ch 18 Pharmacology Long Questions
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Q1. What roles do drugs play in our life?
• It can cause lowering of blood pressure
• Cure infections like Respiratory tract, Urinary tract, Intestine, Middle ear and skin infections
• Used as pain killers like sedative medicines.
• Used to treat bacterial and viral infections like vaccines and antibiotics.
• An antibiotic is a drug that kills or retard the growth of bacteria. These are the chemicals produced or derived from microorganisms like bacteria and fungi i.e. Penicillin
• A material containing weakened or killed pathogens and is used to produce immunity to a disease by stimulating the production of antibodies is called as vaccine i.e. Polio vaccine
Q2. Differentiate between narcotics and drugs. What are the different symptoms of drug addiction?
Ans. Drugs]
- Any substance that, when absorbed into the body of a living organism, alters normal body functions is known as a drug.
Narcotics
- Any substance, illegal or legal that relieves pain but also dulls the senses in large doses cause lack of responsiveness or consciousness.
Symptoms of drug addiction: Different drugs have different physical effects, the symptoms of addiction are similar. Addiction in terms of physical, behavioural and psychological signs are followings:
a) Physical signs of drug abuse:
• Change in appetite or sleep patterns.
• Sudden weight loss or weight gain
• Deterioration of physical appearance
• Unusual smells on breath, body or clothing
• Tremors, slurred speech, or impaired coordination
b) Behavioural signs of drug abuse:
• Unexplained need for money or financial problems. May borrow or steal to get it.
• Engaging in secretive or suspicious behaviours.
• Sudden change in friends and hobbies
• Frequently getting into troubles (fights, accidents, illegal activities)
c) Psychological warning signs of drug abuse:
• Sudden mood swings, irritability, or angry outbursts
• Periods of unusual hyperactivity
• Lack of motivation
• Appears fearful, anxious with no reason.
Q3. What are hallucinogens? Give examples with their sources.
As. • Hallucinogens: These are the drugs that cause hallucination.
Hallucination: Hallucination is change in person perception of reality, thought, emotions and consciousness.
Mode of action: Physiologically, hallucinogens effect on sympathetic nervous system causing
• constriction in some arteries,
• Rise in blood pressure.
• Under the influence of hallucinogens, people see images, hear sounds and feel sensation that seem real but actually do not exist. It disrupt the interaction of nerve cell and chemical messenger in the brain
Examples: Many types of substances are classified as hallucinogens and are illegal to use. Some example are followings:
Marijuana (hashish): It is a hallucinogen which is smoked.
Sources: It is obtained from the flowers, stem and leaves of marijuana plant, Cannabis sativa, cannabis indica.
Loss dosage: Small doses of marijuana results in a feeling of wellbeing that lasts for two or three hours. Taken through smoke or orally it produce feelings like excitement, relaxation, laughter and perception of slowing down of time etc.
High dosages: High doses increase heart rate.
Adverse effect: It also effects the production of sperm and also weakens the short term memory, produce anxiety, dizziness, fear dry mouth, less coordination, poor sense of balance and slower reaction time,.
Usage: Marijuana is one of the most commonly used drugs in world, followed by caffeine, nicotine and alcoholic beverages in popularity.
Mescaline: it is derived from cactus plant and is taken orally
Psilocybin: it is extracted from a mushroom and is taken orally.
Dextromethorphan: It resemble to morphine in chemical structure and is synthesized in laboratories. It isused in cough syrups.
Q4. Describe the mechanism of action of three groups of antibiotics. Also mention the disease for which each of these groups is used.
Ans. Antibiotics: An antibiotic is a drug that kills or retard the growth of bacteria. These are the chemicals produced or derived from microorganisms like bacteria and fungi.
Groups of antibiotics: There are three major groups of antibiotics on the basis of chemical structure:a) Cephalosporin, b) Tetracycline. c) Sulpha drugs-sulfonamides.
i. Cephalosporin:
Category: Cephalosporin are bactericidal.
Source: derived from a specie of bacteria cephalosporin.
Mode of action: Cephalosporin interfere with the synthesis of bacterial cell wall.
Indication: These are used to treat
• Sore throat
• Tonsillitis
• Bronchitis
• Various infections like skin infection, gonorrhoea and urinary tract infection.
ii. Tetracycline:
Category: these are broad spectrum bacteriostatic antibiotics.
Source: these are derived from a specie of Streptomyces bacteria.
Mode of action: Tetracycline inhibit bacterial protein synthesis.
Indications: These are used in the treatment of infections of:
• Urinary tract
• Intestine, Middle ear and skin infections
Contradictions: Tetracycline are not used in children under the age of 8 and especially during periods of tooth development.
iii. Sulpha drugs-sulfonamides
Composition: These are synthetic antibiotics that contain sulfonamide group.
Category: These are broad spectrum bacteriostatic antibiotics.
Mode of action: They inhibit the synthesis of folic acid in bacteria that is usually required to make new DNA. So bacteria stop dividing.
Indication: sulfonamides are used to treat:
• Urinary tract infection.
Q5. What are vaccines? Describe the different ways of producing vaccines.
Ans. Vaccine: A material containing weakened or killed pathogens and is used to produce immunity to a disease by stimulating the production of antibodies is called as vaccine.
Explanation: Vaccines protect kids against severe and life-threatening disease. Vaccines are made using the disease-causing virus or bacteria, but in a form that will not harm your child. Instead, the weakened, killed, or partial virus or bacteria prompts your baby’s immune system to develop antibodies, or defenders, against the disease.
Ways of producing vaccines: There are four different ways that viruses and bacteria are weakened to make vaccines:
• Change the virus blueprint (or genes) so that the virus replicate poorly. This is how measles and mumps vaccines are made. The virus blueprint is changes by technique called cell culture adaptation (adapting a virus to grow in a specialized cell grown n lab instead of cells it normally grows in). Because viruses can still, to some extent, make copies of themselves after cell culture adaptation, they are often referred to as live, attenuated (or weakened) viruses.
• Destroy the virus blueprint (or genes) so that virus can’t replicate. This is how the killed polio vaccine is made.
• Use only a part of virus or bacteria. This is how hepatitis B vaccines are made. Because viral or bacterial genes are not present in the vaccine, the viruses or bacteria can’t replicate.
• Take the toxin that is released from the bacteria, purify it, and kill it so it can’t do any harm. Some bacteria cause disease not by replicating but by manufacturing harmful proteins called toxins. For example bacteria like diphtheria, tetanus and pertussis (whooping cough) all cause disease by producing toxins. To make vaccines against these bacteria, toxins are purified and killed with chemicals (such as formaldehyde). Again as bacterial genes are not part of the vaccine bacteria can’t replicate
Q6. What are the different classes of antibiotics and what is resistance to antibiotics?
Ans. Antibiotics: An antibiotic is a drug that kills or retard the growth of bacteria. These are the chemicals produced or derived from microorganisms like bacteria and fungi.
Classes/types of antibiotics: There are two main types of antibiotics.
Bactericidal Antibiotics: The antibiotics that kill the bacteria are called bactericidal antibiotics.
Bacteriostatic Antibiotic: The antibiotics that work by stopping the bacterial growth are called bacteriostatic antibiotics.
The main classes of antibiotics on the basis of chemical structure are:
• Macrolides (macrocyclic lactone ring,)
• Fluoroquinolones (synthetic compound, bactericidal)
• Tetracycline (contain hexagonal rings, Bacteriostatic)
• Aminoglycosides (bactericidal)
Antibiotic resistance: Antibiotics are extremely important in medicine, but unfortunately bacteria are capable of developing resistance to them. Such bacteria are not affected by commonly used antibiotics.
Definition: The ability of bacteria not to be affected by the particular antibiotic is called antibiotic resistance
Reason: when bacteria are exposed to the same antibiotic over and over, they can change and are no longer affected by the drug.
Ways of developing resistance: Bacteria have numbers of ways of developing resistance.
• Transfer of genes: Bacteria can also transfer the genes responsible for antibiotic resistance between them. So such resistance bacteria make it possible for other bacteria to acquire resistance.
• Unethical usage: Another reason for increasing antibiotic resistance in bacteria is their use in disease in which they have no efficiency e.g. antibiotics are not effective against infection caused by viruses.
A growing problem: resistance to antibiotics possess a serious and growing problem, because some infectious diseases are becoming more difficult to treat. Some of the resistant bacteria can be treated with more powerful antibiotics, but there are some infections that do not eliminate even with new antibiotics.
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