Chapter 7 Flashcards
Human Nutrition (Diet)
What is a balanced diet?
A balanced diet is a diet that contains all essential nutrients our body requires in the right amounts.
Carbohydrates, Fats and Proteins.
Which nutrient gives the most energy?
Fats give the greatest amount of energy.
How is energy measured?
Energy from food is measured in calories or Joules.
How much energy does a gram of Carbohydrates give?
16 KJ
How much energy does a gram of Protein give?
17 KJ
How much energy does a gram of Fats give?
37 KJ
How much energy does our body require each day?
Our body needs to obtain 12,000 KJ of energy everyday.
What is Basal Metabolism?
This type of metabolism maintains circulation, breathing, body temperature, brain function and essential processes in the Liver and other organs.
*2400 KJ is needed for this.
What is the importance of Proteins?
Proteins supply the amino acids our body needs to build up structures. (cytoplasm and enzymes).
- Proteins provide chemical substances to build cells and tissues.
What are some examples of Protein?
Some examples are meat, fish, eggs, milk and cheese.
Plants contain proteins like soybean, pumpkin seeds and nuts.
What is the importance of Carbohydrates?
- Carbohydrates are the cheapest and most readily available sources of energy.
- Sugar and Starch appear as Sucrose in our diet.
- Carbohydrates are oxidized to Carbon dioxide and water, giving energy by respiration.
*Cellulose from plants is also a Carb used for roughage.
What happens to excess Carbohydrates?
Excess Carbs are converted to Glycogen or fat in the liver.
- The Glycogen is stored in the Liver and muscles
- The Fat is stored in fat deposits (abdomen, around kidneys, under skin)
What are some examples of Carbohydrates?
Potatoes, bread, maize, rice and cereals.
What is the importance of Fats/Oils?
Fats and oils are called Lipids.
- These are used in cells to form the cell membrane and other membrane systems.
- Lipids are also oxidized for energy by respiration to Carbon Dioxide and Water.
- Fats can be stored long-term in the body.
What are some examples of Fats?
Butter, Milk, egg yolks, cheese, peanuts.
What is Adipose tissue?
This fatty tissue forms a layer under the skin that prevents heat loss if blood supply is restricted.
What is the importance of Vitamins?
Vitamins are a group of organic substances.
- They are essential for health and needed for chemical reactions in cells that associate with enzymes.
What are the 2 classes of Vitamins?
The 2 classes are:
- Fat-soluble vitamins; Found in animal fats or vegetable oils.
- Water-soluble vitamins; Present in green leaves, fruits and cereal grains.
What is the importance of Fibre?
- Fibre is bulky which helps food move down the canal during Peristalsis more efficiently.
- Fibre protects the intestines from cancer and other disorders.
*It also fills you up, so you wont overeat.
What happens if theres high intake of Fats?
Plaques are fatty deposits.
High intake of fats increases the level at which plaques form in the arteries.
This leads to Coronary Heart Disease or strokes.
How are Plaques formed?
Plaques are fatty deposits.
They are formed from Lipids and Cholesterol combined with Proteins.
(LDL’s - Low Density Lipoproteins)
What happens if theres lack of Fibre?
Lack of Fibre leads to constipation.
What is Malnutrition?
Malnutrition is the lack of a balanced diet.
This leads to weight loss, weakness and Starvation.
What is Scurvy?
Scurvy is a disease that occurs when theres lack of Vitamin C.
It causes bleeding under the skin, like in the gums, and causes stunt growth.
What is Rickets?
Rickets is a disease caused by lack of Vitamin D.
In children, the bones remain soft and deformed, having stunted growth
In adults, it causes Osteo-malacia. (Fractures)
What is the importance of Iron?
Iron is needed in red blood cells.
Haemoglobin present in rbc’s contains iron, which is needed to carry O2 around the body.
What happens when theres lack of Iron?
Lack of iron leads to Anaemia. Insufficient Haemoglobin is made, so theres less Oxygen carried around the body.
What happens to the iron in rbc’s after they break down?
Most Iron is stored in the Liver, however some is lost, and taken in through minerals.
Which foods have a source of Iron?
Red meat, Liver, Kidney, Spinach, Brown rice.
What is the importance of Calcium?
- Calcium is needed for the development of bones and teeth, making them hard.
- Calcium is present in blood plasma and plays a part in blood clotting.
- Calcium is needed for the transmission of nerve impulses.
What foods contain a source of Calcium?
Milk and cheese.
What is the importance of Vitamin D?
It is needed for bone development, and helps in absorption of Calcium (along with bile salts).
What is the importance of Water?
Water is a solvent and transport medium for substances during digestion.
How does Fibre prevent constipation?
Fibre adds bulk to contents in the Colon which help it retain water.
This softens faeces, and makes it easier for waste to pass out of the body.
What foods contain a source of Fibre?
Vegetables, Fruits and wholemeal bread.
What is Kwashiorkor? (+symptoms)
It is the lack of protein in a diet. It is PEM (Protein-energy Malnutrition)
- This occurs when a baby is weaned to a diet with an inadequate amount of protein.
- Symptoms are dry skin, pot belly, weakness.
What is Marasmus? (+symptoms)
Marasmus means Decay.
- It is the lack of carbohydrates and proteins.
- Symptoms are skin is thin and hangs in folds, infections and dehydration.
