Chapter 15

PARAMOUNT SCHOOL SYSTEM

Subject: Chemistry – I

Unit 15: Hydrocarbons

CONCEPT ASSESSMENT EXERCISE 15.1

1. Differentiate between DNA and RNA.

DNA RNA
DNA stands for Deoxyribonucleic Acid. RNA stands for Ribonucleic Acid.
DNA exists in the form of two strands. RNA exists in the form of single strands.
It is made of a deoxyribose sugar, phosphorus unit and nitrogen base. It is made of a ribose sugar, phosphorus unit and nitrogen base.
Storing genetic information. Transferring genetic information from the DNA to proteins.

2. Differentiate between proteins and lipids.

Proteins Lipids
Made of chains of amino acids. Made of fatty, waxy, or oily compounds.
Provide 4 kilocalories per gram. Provide 9 kilocalories per gram.
Build and repair tissues. Store and move energy.
Act as enzymes and hormones. Form cell membranes and hormones.
Found in meats, beans, and nuts. Found in oils, butter, and fatty foods.

Look at the density chart and examine:

1. Which food causes high blood pressure?

Salt causes high blood pressure.

2. What are the dangers of high-calorie foods?

High-calorie foods increase the risk of weight gain and obesity.

3. Why is it good to eat low-calorie foods? And why?

It is good to eat low-calorie foods because they provide less fat, more water, and fiber, which helps in managing hunger and maintaining a healthy weight.

REVIEW QUESTIONS

1. Encircle the correct answer.

  1. In small village children frequently suffered from different infectious diseases due to weak immune systems. Which major nutrients were lacking in their food?

(a) Amino acids (b) Carbohydrates (c) Proteins (d) Lipids

  1. Which of the following food components are rich in fats:

(a) Rice and maize (b) Pulses and wheat

(c) Milk, egg, and beans (d) Cheese, butter, and oil

  1. Potatoes, cereals, beans, pulses, and oats are rich in:

(a) Proteins (b) Carbohydrates (c) Amino acids (d) Fats

  1. What is a bond between amino acids called?

(a) Ionic bond (b) Acidic bond (c) Peptide bond (d) Hydrogen bond

  1. The major function of carbohydrates includes:

(a) Storage (b) Structural framework

(c) Defense system of body (d) Messenger

  1. Which of the following disorders is NOT caused by the deficiency of proteins?

(a) Weight loss (b) Muscle fatigue

(c) Loss in muscle strength (d) Constipation

  1. Foods containing starch and carbohydrates are important because:

(a) They make your bones strong. (b) They stop you from getting overweight.

(c) They are easy to cook. (d) They give you energy.

  1. Meat, fish, and other alternatives provide the following important nutrients:

(a) Carbohydrates (b) Protein (c) Lipids (d) Sugar

  1. Which nutrient builds, maintains, and repairs body tissues and cells?

(a) Carbohydrates (b) Protein (c) Lipids (d) Water

  1. Marium’s doctor told her that she is facing a shortage of blood and has anemia. What nutrients are lacking in Marium’s diet?

(a) Carbohydrates (b) Protein (c) Lipids (d) Water

2. Give short answer.

  1. Give three reasons why living organisms need food.
  2. Food provides the fuel needed for all bodily functions and activities.
  3. Food supplies essential nutrients for growth, repair, and maintenance of tissues.
  4. A balanced diet helps prevent diseases and supports overall health.
  5. What is a balanced diet? What is the importance of balance diet?

A balanced diet provides all the nutrients in suitable amounts needed to carry out life processes. It includes a variety of foods in limited amounts and proportions to satisfy the needs for calories, proteins, minerals, vitamins, and other nutrients.

Importance of a Balanced Diet:

  • Reduces high blood pressure.
  • Lowers high cholesterol.
  • Prevents diseases like obesity, diabetes, cardiovascular diseases, cancer, and skeletal problems.
  • Increases bone health and muscle strength.
  1. State four functions of proteins. Give one example to illustrate your answer.
  • Proteins are a source of energy for the body.
  • Proteins help the body to grow.
  • Proteins repair tissues in the body.
  • Proteins maintain body tissues and cells.

Example: Proteins found in eggs, help repair and maintain body tissues, provide energy, and support growth.

  1. Suggest two major foods a mother could give to her growing child? And why.

Meat or Fish: These are rich in proteins, which are essential for the child’s growth, wound healing, and overall development. Proteins help in building and repairing body tissues, making them crucial for a growing child.

Fruits and Vegetables: These provide essential vitamins and minerals, which are vital for the child’s immune system, bone health, and overall well-being. A balanced intake of these nutrients ensures the child stays healthy and develops properly.

  1. Carbohydrates are a major source of energy. Defend the statement.

Carbohydrates are a major source of energy because they are broken down into glucose, which fuels our body’s cells, tissues, and organs. Each gram of carbohydrate provides 4 kilocalories of energy. When carbohydrates are not available, the body uses proteins and fats as alternative energy sources, but glucose is the preferred fuel, especially for the brain.

  1. Fatima has fond of junk food like French fries, burgers, and pizza. What will happen if Fatima only eats junk food? What should she add to her routine food?

If Fatima only eats junk food like French fries, burgers, and pizza, she may face health issues such as weight gain, high cholesterol, and increased risk of diseases like diabetes and heart disease due to the high fat, sugar, and salt content. To improve her health, she should add more vegetables, fruits, whole grains, and lean proteins to her routine food.

3. What are lipids? How are lipids important to our body?

Lipids are fatty, waxy, or oily compounds insoluble in water but soluble in organic solvents. They include fats and oils.

Importance of Lipids:

  • Store energy.
  • Provide insulation and protection for the body.
  • Help absorb fat-soluble vitamins.

4. How do you maintain a balanced diet?

To maintain a balanced diet, I:

  • Eat a variety of foods in the right amounts.
  • Include carbohydrates, proteins, lipids, vitamins, minerals, and water in my diet.
  • Focus on eating more vegetables and fruits.

5. What percentage of fat is required in a balanced diet? Why is the percentage of fat being lowest in major food components? Justify

In a balanced diet, fat should make up about 33% of the total intake. The percentage of fat is the lowest among major food components because fats provide more energy (9 kilocalories per gram) compared to carbohydrates and proteins (4 kilocalories per gram). Therefore, to balance energy intake and prevent excessive calorie consumption, the fat percentage is kept moderate.

6. What are the sources and functions of nucleic acids?

Sources of Nucleic Acids:

  • Seeds
  • Grain
  • Fish eggs

Functions of Nucleic Acids:

  • DNA carries genetic information and allows it to be passed to the next generation.
  • RNA helps in converting genetic information into proteins.

7. Imagine you are a nutritionist task to design a meal plan for athletes participating in a marathon. Explain the role of carbohydrates can affect an athlete’s performance during the marathon.

Carbohydrates, like oatmeal, whole-grain bread, pasta, rice, bananas, and sweet potatoes, are the main energy source for running. They break down into glucose, fueling muscles and maintaining energy. Adequate intake before and during the marathon keeps glucose levels stable, delaying fatigue and enhancing performance, ensuring athletes have enough stored energy throughout the race.