THE BEGUSARAI POST
PROTEINS AN INTRODUCTION
- What are Proteins
- Importance of Proteins
- Classification of Proteins
- Foods containing Protein
WHAT ARE PROTEINS?
- They are the fundamental constituents of all protoplasm and are involved in the Structure of the living cell and in its functions.
- Enzymes are made up of proteins
- Many of the hormones are Proteins.
- The cement substances and the reticulum, which bind or holds the cells are tissue or organs are made up partly of proteins
- They execute their activities in the transport of oxygen and carbon dioxide by haemoglobin and special enzymes in the red blood cells.
- They function in the homeostatic control of the volume of the circulating blood, that of the intestinal fluids through the plasma proteins.
- They are involved in blood clotting through thrombin, fibrinogen and other Proteins factors.
- They act as the defence against infection by means of protein antibodies.
- They perform hereditary transmission by nucleo proteins of the cell nucleus.
Classification of Proteins
- Electrochemical indications (acidic, basic and neutral). Explain and give examples
- polarity ;polar (hydrophobic), nonpolar (hydrophilic), amphiphilic. Explain these terms.
- Function (transport, enzymes, hormones, antibodies etc)
- chemical composition(simple and complex)
- Simple proteins(Describe the amino acid composition, the molecular mass, the charge , the structure and functions of the following:) Protamines -Albumin, Histones -Globulin
Simple proteins
Class of Proteins |
Characteristics |
Examples |
Albumin |
Soluble in water, coagulable by heat and precipitated at high salt concentrations. |
Serum albumin, egg albumin, lactal albumin (Milk), leucosin (wheat), legumelin (soyabeans). |
Globulin |
Insoluble in water, soluble in dilute salt solutions and precipitated by half saturated salt solutions. |
Serum globulin, vitellin (egg yolk), tuberin (potato), myosinogen (muscle), legumin (peas). |
Glutelin’s |
Insoluble in water but soluble in dilute acids and alkalis. Mostly found in plants. |
Glutenin (wheat), oryzenin (rice). |
Prolamins’ |
Insoluble in water and absolute alcohol but soluble in 70 to 80 per cent alcohol. |
Gliadin (wheat), zein (maize). |
Protamine’s |
Basic proteins of low molecular weight. Salmine (salmon sperm). Soluble in water, dilute acids and alkalis. |
Not coagulable by heat. |
Histones |
Soluble in water and insoluble in very dilute ammonium hydroxide. |
Globin of haemoglobin and thymus histones. |
Scleroproteins |
Insoluble in water, dilute acids and alkalis |
Keratin (hair, HOM, nail, hoof and feathers), collagen (bone, skin), elastin (ligament). |
Conjugated Proteins
Class of Proteins |
Characteristics |
Examples
|
Nucleoproteins |
Composed of simple basic proteins (protamines or histones) with nucleic acids, found in nuclei. Soluble in water. |
Nucleoprotamines and nucleohistones. |
Lipoproteins |
Combination of proteins with lipids, such as cholesterol and phospholipids etc. |
Lipoproteins of egg-yolk, milk and As fatty acids, membranes, lipoproteins of blood. |
Glycoproteins
|
Combination of proteins with carbohydrate (mucopolysaccharides). |
Mucin (saliva), ovomucoid (egg white osseomucoid (bone),
tendomucoid (tendon). |
Phosphoproteins
|
Contain phosphorus radical as a prosthetic group |
Caseinogen (milk), ovovitellin (egg yolk) |
Metalloproteins |
Contain metal ions as their prosthetic groups. The metal ions generally are Fe, Co, Mg, Mn, Zn, Cu etc. |
Siderophilin (Fe), ceruloplasmin (Cu). |
Chromoproteins |
Contain porphyrin (with a metal Ion) as their prosthetic
group |
Haemoglobin, myoglobin, glactase |
Flavoproteins |
Contain riboflavin as their prosthetic Flavoproteins of liver and kidney groups. |
Flavoproteins of liver and kidney |
Complex Proteins
- The chemical composition and structure of complex proteins.
- Protein component- Apoprotein
- Nonprotein component-Prosthetic group
- Principle of classification (based on the name of the prosthetic group) and classes of complex proteins.
- Dairy Products
- Greek Yoghurt
- Cottage Cheese
- Regular Yoghurt
- Milk, Skim
- Soy milk
- Mozzarella
- String Cheese
- Meat, Poultry, Eggs
- Chicken, skinless
- Steak
- Turkey, roasted.
- Lamb
- Pork
- Ham
- Egg,
- Seafood
- Salmon
- Tuna
- Shrimp
- Lobster
- Scallops
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