Biology 2.1
- Food products and nutrients
Foods = all the products that you can eat or drink
- Vegetable foodstuffs: the roots, stems, leaves, fruits or seeds
- Animal-based foodstuffs: parts of animals (meat or fish) and
products of animals (eggs, milk)
- Dietary fibre: all the indigestible parts of a plant derived food
Nutrients Functions
- Building blocks: used in making cells and tissues (particularly for growth,
development and recovery in the body)
- Fuels: provide energy needed for movement and to keep your body temperature up
and for growth, development and repairs to your body
- Food reserves: are stored in certain parts of the body
- Protective substances that make sure that you stay healthy
The nutrients and their function
- Proteins: building blocks, also as fuel
> Too many proteins are converted into fad and stored as food reserves
- Carbohydrates: fuel, also as building blocks and reserves
> Sugars (glucose), starch and glycogen are examples of carbohydrates
> Too many proteins are converted into fad and stored as food reserves
> Glucose can be converted into glycogen and stored in the liver and the muscles
- Fats: fuel, also building blocks and reserves
> Fats can also be stored as food reserves under the skin
- Water: building materials
> Is important for instance in transporting substances around the body
- Minerals (salts): building materials and protective substances
> Example: calcium phosphate for building bones
- Vitamins: building materials and protective substances
> Vitamins are identified by letters
> Examples: vitamin A for producing skin and seeing well; vitamin d for fixing
calcium phosphate in bones
, Biology 2.2
- The digestive system
Digestive system
- A system where nutrients from the food are absorbed into the bloodstream.
> Some nutrients can pass through the wall of the intestines and be taken up into
the blood. (water, minerals, glucose and vitamins)
> Other nutrients cannot pass through the intestinal wall. (proteins, carbohydrates,
starch and fats)
Chewing and breaking down larger nutrients molecules
- During digestion, larger nutrient molecules are broken
into smaller digestion products.
> The breakdown is done in 2 steps:
1. ) Converting the nutrients using digestive juices
2. ) Breaking the food into small pieces by chewing
- You have different types of teeth:
> 1. ) incisors: cutting off pieces of food
2. ) canines: cutting off pieces of food (canines are more pointed than the incisors)
3. ) molars: knobbly top surface, breaks your food down into small pieces
- Chewing also has a digestive function, because food has been broken down into
little pieces.
> This is known as mechanical digestion.
- Chewing your food increases its surface area
Digestive juices
- Digestive juices make sure that the substances in your food are broken down into
smaller and smaller substances. (digestion products)
- Chemical reactions take place: substances are converted into other substances.
> the part of the digestive process is therefore called chemical digestion
- Examples of digestive juices are saliva and gastric.
- Digestive juices are made by the digestive glands.
> The digestive glands are:
1. ) the salivary glands
2. ) the gastric glands
3. ) the liver
4. ) the pancreas
5. ) the intestinal glands
- Food products and nutrients
Foods = all the products that you can eat or drink
- Vegetable foodstuffs: the roots, stems, leaves, fruits or seeds
- Animal-based foodstuffs: parts of animals (meat or fish) and
products of animals (eggs, milk)
- Dietary fibre: all the indigestible parts of a plant derived food
Nutrients Functions
- Building blocks: used in making cells and tissues (particularly for growth,
development and recovery in the body)
- Fuels: provide energy needed for movement and to keep your body temperature up
and for growth, development and repairs to your body
- Food reserves: are stored in certain parts of the body
- Protective substances that make sure that you stay healthy
The nutrients and their function
- Proteins: building blocks, also as fuel
> Too many proteins are converted into fad and stored as food reserves
- Carbohydrates: fuel, also as building blocks and reserves
> Sugars (glucose), starch and glycogen are examples of carbohydrates
> Too many proteins are converted into fad and stored as food reserves
> Glucose can be converted into glycogen and stored in the liver and the muscles
- Fats: fuel, also building blocks and reserves
> Fats can also be stored as food reserves under the skin
- Water: building materials
> Is important for instance in transporting substances around the body
- Minerals (salts): building materials and protective substances
> Example: calcium phosphate for building bones
- Vitamins: building materials and protective substances
> Vitamins are identified by letters
> Examples: vitamin A for producing skin and seeing well; vitamin d for fixing
calcium phosphate in bones
, Biology 2.2
- The digestive system
Digestive system
- A system where nutrients from the food are absorbed into the bloodstream.
> Some nutrients can pass through the wall of the intestines and be taken up into
the blood. (water, minerals, glucose and vitamins)
> Other nutrients cannot pass through the intestinal wall. (proteins, carbohydrates,
starch and fats)
Chewing and breaking down larger nutrients molecules
- During digestion, larger nutrient molecules are broken
into smaller digestion products.
> The breakdown is done in 2 steps:
1. ) Converting the nutrients using digestive juices
2. ) Breaking the food into small pieces by chewing
- You have different types of teeth:
> 1. ) incisors: cutting off pieces of food
2. ) canines: cutting off pieces of food (canines are more pointed than the incisors)
3. ) molars: knobbly top surface, breaks your food down into small pieces
- Chewing also has a digestive function, because food has been broken down into
little pieces.
> This is known as mechanical digestion.
- Chewing your food increases its surface area
Digestive juices
- Digestive juices make sure that the substances in your food are broken down into
smaller and smaller substances. (digestion products)
- Chemical reactions take place: substances are converted into other substances.
> the part of the digestive process is therefore called chemical digestion
- Examples of digestive juices are saliva and gastric.
- Digestive juices are made by the digestive glands.
> The digestive glands are:
1. ) the salivary glands
2. ) the gastric glands
3. ) the liver
4. ) the pancreas
5. ) the intestinal glands
