Proteins. Flashcards
What are the five things proteins is vital for?
- Growth of hair, nails and skin.
- Repair.
- Maintenance.
- Energy.
- Production of hormones/ enzymes/ antibodies.
What are the four main and two sometimes elements found in proteins?
The main elements found in protein are:
Oxygen (O) Carbon (C )
Hydrogen (H) Nitrogen (N)
And sometimes:
Sulphur (S) Phosphorus (S)
What are amino acids?
The protein molecules are made up of small units joined together like links in a chain. These units are called amino acids.
What is the name for proteins that contain all of the indispensable amino acids?
Proteins that contain all the indispensable amino acids are called HBV Proteins (High Biological Value). They are also sometimes called complete proteins.
What is the name for proteins that lack one or more of the indispensable amino acids?
Proteins that lack one or more of the indispensable amino acids are called LVB (Low Biological Value) proteins. These are sometimes called incomplete proteins.
HBV proteins are found mainly in _____ foods: Give 5 examples.
Meats, cheeses, fish, milk, eggs
LBV proteins are mainly found in _____ foods: Give five examples.
Cereals e.g. wheat, rice, oats Pulses, e.g. peas, beans. Some nuts Vegetables (a little) Quorn mycoprotein
What are the two exceptions of plant and animal food proteins?
Soya beans (plant) contain High Biological Value Gelatine (animal) contains Low Biological Value.
How can you make Low Biological Value protein foods less inferior to High Biological Value protein foods?
If a combination of LBV proteins foods are eaten together then the essential amino acids which are limited in one are provided by the other.
If a combination of LBV proteins foods are eaten together then the essential amino acids which are limited in one are provided by the other.
Give two examples of this statement.
Beans on toast (wheat), lentil soup with bread, or beans and rice.
What are complementary proteins?
Combining two Low Biological Value proteins/ one Low Biological Value + High Biological Value protein creates a complementary protein, which then gives the body the complete proteins.
What are the protein requirement and reasons for babies and children, adolescents, pregnant women and a nursing mother?
Babies and children require a lot of protein as they are growing rapidly
Adolescents require protein for their rapid spurt of growth
Pregnant women require more than normal to cater for their growing baby.
Nursing mothers require more than normal for milk production during breastfeeding (lactation).
What are the two deficiency diseases of proteins?
Marasmus and kwashiorkor.
Marasmus – affects babies one year old.
How does a baby with maramus become very thin and weak and could in fact die?
The body adapts to the shortage of food by the wasting of muscles and depletion of fat stores, so that energy is supplied to vital organs.
What are the 5 results/ effects of kwashiorkor?
Retarded growth, Chronic diarrhea and infections, Deterioration of hair, skin, and nails Retention of fluid under the skin, causing swelling (oedema) Poor digestion of food
What is denaturation in the case of proteins?
When proteins are heated, their chemical structure is permanently altered or denatured (changed). This cannot be reversed.
What happens when proteins are overheated?
If overheated, they become less digestible.
What happens to proteins as they are continually heated?
As heating continues, proteins coagulate (set), and generally become less soluble.
Deaminations is an effect of the excess intake of proteins. What is deamination?
Deamination happens when the nitrogen element is removed from the amino acid.
Deamination happens when the nitrogen element is removed from the amino acid. How is this excess intake of proteins a bad thing?
This happens in the liver and produces ammonia which is toxic and is then excreted as urea in urine via the kidneys. The remainder is oxidised for energy or converted to fat.
What two enzymes breakdown proteins in the stomach? And what do they do exactly?
Pepsin breakdown proteins into small chains of amino acids called peptides.
Renin clots milk so that the pepsin can act on it more efficiently.
What enzyme breaks down proteins in the duodenum? And what does it do exactly?
Trypsin breakdown proteins into peptones.
What enzyme breaks down proteins in the ileum? And what does it do exactly?
Erepsin converts peptones to amino acids to complete protein digestion.
How are amino acids absorbed?
Amino acids are absorbed in the villi, into the blood capillaries then into the circulatory system.
