Protein (1)

Question 1

Elements in a protein

Answer 1

Carbon, hydrogen, oxygen and nitrogen (CHON)

Question 2

Digestion of proteins

Answer 2

The digestion of proteins begins in the stomach. Partially digested proteins from the stomach are broken down into amino acids in the small intestine

Question 3

Define and name the essential amino acids

Answer 3

Amino acids that the human body is unable to produce and they must be obtained from food

1. Histidine
2. Valine
3. Lysine
4. Isoleucine
5. Leucine
6. Methionine
7. Phenylalanine
8. Threonine
9. Tryptophan

Question 4

Define and name the non-essential amino acids

Answer 4

Amino acids that the body is able to produce and they need not be obtained from food

1. Proline
2. Serine
3. Glycine
4. Tyrosine
5. Alanine
6. Arginine
7. Glutamine
8. Cysteine
9. Asparagine
10. Aspartic acid
11. Glutamic acid

Question 5

Define
1. Biological value
2. Proteins of high biological value
3. Proteins of low biological value
4. Complementary proteins

Answer 5

1. Biological value is the measure of how well a protein can be absorbed and used by the body
2. Proteins of a high biological value are also known as complete proteins. They supply the body with all the essential amino acids in the right amounts (Chicken, soya beans, quinoa)
3. Proteins of low biological value are also known as incomplete proteins. They lack one or more essential amino acids that is needed by the human body (Almonds, Barley, sunflower seeds)
4. Complementary proteins are formed by combining two or more low biological value proteins such that the body obtains all the essential amino acids for various body functions (Dhal with rice, baked beans on bread)

Question 6

Functions of proteins in the body (First 4)

Answer 6

1. Proteins are important to support growth, maintain good health and are needed for the body to repair and replace worn-out cells and tissues
2. Proteins (e.g. collagen) are important components in the skin, nails, ligaments, muscles, tendons and other tissues. They provide structure and internal support for the human body and organs.
3. Proteins help to transport gases, nutrients and wastes from one tissue to another in the body. (E.g. haemoglobin, a protein found in red blood cells, delivers oxygen from the lungs to other parts of the body)
4. Enzymes are made of proteins and they are involved in chemical reactions in the body. (E.g. Digestive enzymes are needed to break down large food molecules into smaller substances during digestion)

Question 7

Functions of proteins in the body (Last 3)

Answer 7

1. Proteins are needed to support a strong immune system. Proteins in the form of antibodies protect the body against attacks by harmful microorganisms and foreign substances.
2. Proteins act as an energy reserve when there is an insufficient intake of carbohydrates and fats from the diet which results in proteins in the body being forced to break down to supply energy during prolonged starvation. As a result, the body lacks proteins to perform other important tasks. (E.g. building muscles, fighting diseases and regulating body processes) (1g -> 4kcal of energy)
3. Proteins make up a huge portion of the muscles in the body. All body movements are enabled through muscle contraction.