Protein (Diagram Shoudn't be Seen on Mobile) Flashcards
Elemental Composition
Carbon, hydrogen, oxygen, nitrogen and traces of iron, sulphur and phosphorous.
Only nutrient that contains nitrogen because it involved in growth and repair of cells.
Function of Protein: Structural Protein
Make cells.
Growth and repair of cells.
Make skin.
Function of Protein: Physiologically (Active Protein) Specific Job
Make enzymes.
Make hormones e.g insulin and thyroxine.
Make antibodies.
Make blood proteins e.g haemoglobin.
Function of Protein: Nutritive Protein
Supplies body with essential amino acids.
Excess proteins converted to fat for energy.
Deficiency of Protein
Retarded growth in children.
Lack of energy.
Poor functioning of the body systems as enzymes, hormones and antibodies not replaced resulting in illness and infection.
(Higher Level) Marasmus (severe deficiency of protein) causes thin arms, thin legs and sunken face (no protein).
(Higher Level) Kwashiorkor causes retarded growth, dermatitis, distended abdomen and thin hair (some protein).
Recommended Intake of Protein
Based on 1. body weight and 2. rate of growth.
1. 1 grams per kilograms of body weight.
2. Children and pregnant women need slightly higher - increased levels of growth.
Energy Value
1 gram of protein gives 4 kilocaleries of energy.
Should make up 15% of daily energy in an adults diet.
Structure of Protein
Made up of amino acids.
20 amino acids in a chain = peptide.
Over 20 amino acids = polypeptide.
Structure of Amino Acids
All amino acids have the same basic structure.
Basic unit of protein.
Structure of amino acids:
Structure of a Peptide Bond/Link
Two amino acids join via condensation reaction (loss of a water molecule). That is how peptide bond is form. More info on that:
NH2 group of one amino acid reacts with the COOH group of another amino acid.
The NH2 group looses a hydrogen.
5he COOH group looses 1 oxygen and 1 ydrogen.
These combine to form a water molecule H20.
Directive bond forms = one bond made up of several minor acids which join to other dipeptides to form a polypeptide.
(Unable to add a diagram).