Describe the role of enzymes and proteins in digestion.

Assignment Brief

1. Describe how the system works, including what each organ does, where chemical and mechanical digestion occur, the role of enzymes and proteins in digestion.
2. Explain what a balanced diet should consist of, including the purpose of macro-and micronurtrients.
3. Comment on a particular diet of your choice(i have chosen "Lose your weight with Atkins Diet"). Are there any special points people following Atkins diet need to take into consideration? write about good and bad things about this diet.
4. Explain what special dietary requirements people of different ages, for example talk about children`s dietary requirements.
5. Describe what body mass index refers to, and the pros and cons of the different methods of recording it.

Sample Answer

Human Digestive System and Diet

How the Digestive System Works

The digestive system helps our body break down food into smaller parts so we can absorb nutrients and get energy.

Main Organs and Their Functions:

• Mouth: Digestion starts here. Teeth break food into smaller pieces (mechanical digestion). Saliva softens food and starts chemical digestion with enzymes like amylase.

• Oesophagus: A tube that moves food from the mouth to the stomach using muscle movements (peristalsis).

• Stomach: Mixes food with stomach acid and enzymes (chemical digestion). Muscles churn the food (mechanical digestion).

• Small Intestine: Most digestion and nutrient absorption happen here. Enzymes from the pancreas and bile from the liver help break down fats, proteins, and carbohydrates.

• Large Intestine: Absorbs water and forms waste (faeces).

• Rectum and Anus: Store and remove waste from the body.

Chemical and Mechanical Digestion:

• Mechanical digestion: Begins in the mouth (chewing) and continues in the stomach (churning).

• Chemical digestion: Starts in the mouth with saliva and continues in the stomach and small intestine with enzymes.

Role of Enzymes and Proteins:

• Enzymes speed up digestion. For example:

  • Amylase breaks down carbohydrates.

  • Protease breaks down proteins.

  • Lipase breaks down fats.

• Proteins in food are broken into amino acids, which help build and repair body tissues.

What a Balanced Diet Should Include

A balanced diet gives the body everything it needs to work well. It should include:

Macronutrients (needed in large amounts):

• Carbohydrates – provide energy (e.g. rice, bread).

• Proteins – build and repair cells (e.g. meat, fish, beans).

• Fats – store energy and help with cell function (e.g. nuts, oils, dairy).

Micronutrients (needed in small amounts):

• Vitamins – e.g. Vitamin C helps immunity; Vitamin D helps bones.

• Minerals – e.g. Calcium strengthens bones; Iron helps red blood cells.

• Water – essential for all body functions.

Eating the right portions from all food groups helps maintain health.

Atkins Diet – “Lose Your Weight with Atkins Diet”

The Atkins Diet is a low-carb, high-protein diet designed to help people lose weight.

How It Works:

• Reduces carbohydrates and increases fats and proteins.

• Makes the body use fat for energy instead of sugar (called ketosis).

Good Things About Atkins Diet:

• Quick weight loss in the early stages.

• Helps control hunger because of high protein.

• Can improve blood sugar control for some people.

Bad Things or Risks:

• Low in fruits and whole grains, which provide fibre and vitamins.

• May increase cholesterol due to high fat intake.

• Can cause side effects like tiredness, constipation, or headaches.

Special Considerations:

• People with kidney problems or heart disease should avoid it.

• Not suitable for children, pregnant women, or those with certain health conditions.

• It’s important to drink plenty of water and choose healthy fats.

Special Dietary Requirements by Age

Children:

• Need more calcium and vitamin D for bone growth.

• Require iron for brain development.

• Should have a balanced diet with enough energy for growth and play.

• Limit sugary and processed foods.

Teenagers:

• Require more protein, calcium, and iron due to rapid growth.

• Need more energy due to puberty and activity.

Adults:

• Should eat a balanced diet and maintain healthy weight.

• Fibre is important for digestion, and calcium helps with bone strength.

Older Adults:

• Need fewer calories but still need nutrient-rich foods.

• Need more vitamin D, calcium, and B12.

• Should drink plenty of water to avoid dehydration.

Body Mass Index (BMI)

BMI is a tool used to check if someone has a healthy weight for their height.

Formula:

BMI = weight (kg) ÷ height (m²)

BMI Categories:

• Underweight: below 18.5

• Normal: 18.5 – 24.9

• Overweight: 25 – 29.9

• Obese: 30 or more

Pros of BMI:

• Quick and easy to measure.

• Helps identify weight problems.

Cons of BMI:

• Doesn’t show muscle or fat amount.

• May not work well for athletes or very muscular people.

• Doesn’t show where fat is stored in the body.

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