Diet and Nutrition Basics

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Questions and Answers

What are the main components of a healthy human diet?

Carbohydrates, lipids, protein, vitamins, minerals, dietary fibre, and water

What is the primary function of carbohydrates in the body?

To provide energy

What is the significance of proteins in the body?

For growth and repair of cells and tissues

What is the role of calcium in the body?

Used in making bones and teeth Signup and view all the answers

What is the function of fibre in the digestive system?

To add bulk to food and help it pass through the digestive system Signup and view all the answers

What is the consequence of not having a balanced diet?

Malnutrition Signup and view all the answers

What is the purpose of iodine solution in food testing?

To detect the presence of starch Signup and view all the answers

What is the function of Benedict's reagent in food testing?

To detect the presence of simple sugars such as glucose Signup and view all the answers

What is the role of the digestive system in the body?

To break down molecules in food into soluble substances that can be absorbed and used by cells Signup and view all the answers

What is the path that food takes through the digestive system?

Mouth, oesophagus, stomach, small intestine, large intestine, and rectum Signup and view all the answers

What is the main difference between mechanical and chemical digestion in the digestive system?

Mechanical digestion involves physical cutting, squashing, and churning of food, whereas chemical digestion involves the use of enzymes and other chemicals to speed up reactions. Signup and view all the answers

What happens to food in the mouth during digestion?

Both mechanical and chemical digestion occur. Signup and view all the answers

What is the role of the stomach in the digestive system?

The stomach contains acid and facilitates both mechanical and chemical digestion. Signup and view all the answers

What is the function of bile in the digestive system?

Bile is alkaline and neutralizes the acid in the stomach. Signup and view all the answers

What adaptations does the small intestine have to facilitate its function?

The small intestine has many villi, which increase the surface area for diffusion, and a good blood supply to allow for absorption of nutrient molecules into the blood. Signup and view all the answers

What is the role of enzymes in the body?

Enzymes speed up chemical reactions in the body. Signup and view all the answers

What is the specific function of carbohydrates, lipases, and proteases in digestion?

Carbohydrases break down carbohydrates into simple sugars, lipases break down lipids into glycerol and fatty acids, and proteases break down proteins into amino acids. Signup and view all the answers

What is the lock and key theory, and how does it relate to enzymes?

The lock and key theory models how enzymes work by having an active site that is a specific shape to the substrate it joins to. Signup and view all the answers

What are two essential minerals that plants require for healthy growth?

Nitrates and magnesium. Signup and view all the answers

What happens to plants that are deficient in magnesium?

A deficiency in magnesium affects photosynthesis. Signup and view all the answers

Study Notes

Diet and Nutrition

A healthy diet includes carbohydrates, lipids, protein, vitamins, minerals, dietary fiber, and water.
A balanced diet provides all the necessary nutrients in the right quantities.
Carbohydrates provide energy and are found in foods like bread, potatoes, rice, and pasta.
Lipids provide energy and insulation and are found in foods like nuts, dairy products, meat, oils, and sweets.
Proteins are essential for growth and repair of cells and tissues and are found in foods like eggs, pulses, fish, meat, nuts, and dairy products.
Vitamins and minerals are crucial for various bodily processes and are found in high quantities in fruit and vegetables.
Calcium is a mineral that helps build bones and teeth.
Fiber adds bulk to food and aids digestion, found in foods like fruit, vegetables, and wholegrain cereals.
Water is essential for transporting substances and facilitating chemical reactions in cells.

Malnutrition and Health Consequences

Malnutrition occurs when a person lacks a balanced diet.
Diet imbalances can lead to health consequences like obesity, starvation, and deficiency diseases.

Food Tests

Iodine solution changes color from brown to black in the presence of starch.
Benedict's reagent changes color from blue to orange/red when heated in the presence of simple sugars like glucose.
Biuret reagent changes color from blue to purple in the presence of protein.

The Digestive System

The digestive system breaks down food molecules into soluble substances for cell absorption.
Food passes through the mouth, oesophagus, stomach, small intestine, large intestine, and rectum.
Mechanical digestion involves physical breaking down of food, while chemical digestion involves enzymes and chemicals.
In the mouth, both mechanical and chemical digestion occur.
Salivary glands secrete enzymes for chemical digestion.
The stomach contains acid and performs mechanical and chemical digestion.

The Small Intestine

Chemical digestion takes place in the small intestine, and small molecules diffuse into the bloodstream.
The small intestine has villi to increase surface area for nutrient absorption and a good blood supply for absorption into the blood.

Enzymes

Enzymes speed up chemical reactions in the body.
Digestive enzymes break down large nutrient molecules into smaller molecules for blood absorption.
Carbohydrases like amylase break down carbohydrates into simple sugars.
Lipases break down lipids into glycerol and fatty acids.
Proteases break down proteins into amino acids.
The lock and key theory explains enzyme function through specific active sites.

Plant Nutrition

Plants require minerals for healthy growth, including nitrates for protein production and magnesium for chlorophyll production.
Plants obtain necessary minerals from the soil through their roots.
Deficiencies can harm plants, with magnesium deficiency affecting photosynthesis.