The biological Components of Animal Cells

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The biological components of animal cells include- 1. Carbohydrates or sugars, 2. Protein, 3. Lipid or love, 4. Amino acid, 5. Enzyme, 6. Nucleic acids etc. are notable. They are described below:

Carbohydrates:

Carbohydrates account for about 1.5% of the protoplasm or internal contents of cells. Carbohydrates are very important organic compounds in the protoplasm of animal cells. Carbohydrates are found in the free state of animal cells as conjugated proteins with several proteins.

Carbohydrates are basically organic compounds composed of specific proportions of carbon, hydrogen, and oxygen and serve not only as a source of energy. However, the carbon skeleton is also important in building the structural framework of protoplasm. Carbohydrates are the main source of energy in living cells. Carbohydrates that are biologically important to cells are divided into three classes. namely- (i) Monosaccharides, (ii) Disaccharides, and (iii) Polysaccharides.

(i) Monosaccharides: Simple sugars The values of their common symbol Cn(H2O)n n are the same in both cases. They have only one sugar in their structure. These compounds are simple sugars with 3 to 10 carbons. They are classified based on carbon numbers such as triose (3c), tetrose (4c), pentose (5c), hexose (bc), etc. Pentase and hexose monosaccharides are the most important in cells. The pentose sugars ribose and deoxyribose are the main skeletal components of nucleic acids. DNA and RNA are made of their compounds.

Oligosaccharide

The general symbol of oligosaccharides is Cm(H2O)n where n = (m – 1). Disaccharides such as maltose, sucrose, lactose, etc. yield multiple monosaccharides on hydrolysis. Maltose is not found in nature. It is formed in cellular digestion. Lactose is found in milk, sucrose in sugarcane, beets, and sweet potatoes. Trisaccharides like raffinose, verbose, etc. Hydrolysis yields three monosaccharides. Oligo-saccharides are crystalline or granular, soluble in water, and sweet in taste.

(iii) Polysaccharide: Those sugars that yield at least ten or more than a hundred monosaccharides on hydrolysis are called polysaccharides. Sugars of this group are polymer molecules of monosaccharides. Simple examples of polysaccharides are starch, glycogen, cellulose, inulin, etc. Cellulose is found in plant cell walls, glycogen is stored in the liver of the human body, and sugar and starch are found in rice, wheat, and potatoes. Heparin is a complex mucoprotein anticoagulant. It is a complex sugar.

Proteins

Proteins are organic compounds that exist throughout specialized compartments in the macrostructure of protoplasm. Proteins make up about 10% of protoplasm. Different in structure from carbohydrates and lipids. In addition to carbon, hydrogen, and oxygen, their chemical composition contains nitrogen, sulfur, and phosphorus in some cases. Proteins exist in different states in different parts of the cell.

Protein is the main component of protoplasmic gel in hyaloplasm. Hemoglobin is a specialized protein found in human blood that acts as a blood pigment. Hemoglobin is a respiratory pigment present in animal blood. All the reaction catalysts in protoplasm, chemical organic compounds enzymes, which are essential for life are also proteins. Proteins are essentially very complex organic compounds. It contains numerous amino acids (monomers). Amino acid monomer units are bound together by peptide bonds to form complex compounds of very high molecular weight called proteins.

Proteins are conventionally divided into three classes based on solubility and coagulation. Namely-(i) Simple proteins: Hydrolysis of them yields only amino acids or amino acid derivatives. For example, albumin, globulin, protamine, etc.

(ii) Conjugated Proteins: Proteins that hydrolyze into simple proteins and prosthetic groups, eg nucleoproteins, lipoproteins, etc.

(iii) Derived Proteins: The products obtained when proteins are coagulated or hydrolyzed in the unreacted state are called derivatized proteins. Eg- Proteose, Peptone, etc.

Undoubtedly, protein is the main structural component of cells and protoplasm and the functional component of all enzymes. Some hormones are also structural components of proteins. In addition, the cells and components of the body's immune system are made of proteins. Without enzymes and hormones, all cell functions and ongoing energy flow are unimaginable.

Lipids

Lipids are major structural components of various cytoplasmic membranes. About 2% of protozoa are lipid. Among them, sufficient lipids are found scattered throughout the protoplasm to act as food stores in the cell. In addition, phospholipids are the main structural components of almost all cell organelles or membranes. Lipids are compounds of C (carbon), H (hydrogen), and O (oxygen) similar to sugars, but the ratio of hydrogen to oxygen is much greater than 2:1 and is completely insoluble in water.

Chemically, lipids are essentially compounds capable of being esterified with fatty acids. Lipids are essential components of all living cells because phospholipids are made up of cell membranes and all cell membranes, including a part of the protoplasm. Lipids are actual or potential esters of fatty acids that are insoluble in water but soluble in organic solvents like hot alcohol, ether, benzene, etc.

There are three main types of lipids found in cells. Namely-1. Simple lipids. Such as - fatty acids, and glycerol; They are classified as triglycerides.

1. Complex lipids such as phospholipids, glycolipids, sulfolipids, and aminolipids. On hydrolysis, they break down into a different compound other than alcohol, fatty acid.

Steroids

They are compound and complex lipids. For example, adrenal and sex hormones, vitamin D, bile acids, plasma lipids, etc.

Amino Acids

The building blocks of proteins are amino acids. Because protein is formed by chaining amino acid molecules. Amino acids are formed by replacing one or more hydrogen atoms of an organic acid with an amino group (-NH2). All amino acid has an amino group that known as(-NH2). Contains a carboxyl group (-COOH) and an amino acid-specific group (R).

Common molecular symbol of amino acid: R-CH. NH2. COOH There are 20 different types of amino acids found in plants and animals. Some of these amino SDs are – glycine, alanine, valine, leucine, serine, etc.

Enzymes

Among all the proteins, enzymes are very important components of cells. Most of the reactions taking place in living organisms involve the presence of third substances similar to effectors. But their special difference with abiotic agents is that they are secreted from living mediums like cells, organs, organs, glands, etc.

They are effective only in specific locations within the organism. They are active in the specific range of heat, pressure, acidity, and alkalinity of the internal environment of the organism. They are ineffective for any minor changes. Their reactions are highly specific. Physiologically, they are called enzymes.

Enzymes are soluble and colloidal proteins produced by living cells. which, like inorganic agents, do not participate directly (as reactants) in a reaction, but help the reaction rate to reach a steady state specially. Enzymes are secreted from the ductal glands of the animal body and affect reactions at nearby or target sites. The chemicals on which the enzyme acts are called substrates. Enzymes are named by adding “ase” to the end of the substrate name. For example, enzymes acting on proteins are called proteinases, which convert proteins into amino acids.

More such enzymes exist. For example, sucrase, amylase, lipase, urease, protease, etc., and sometimes enzymes are named by adding "ase" to the reaction. For example, oxidase removes reactive oxygen bonds or hydrogen (H) from the reactants of oxidation reactions.

Nucleic acid

Nucleic acid is a polymer of nucleotides. Nucleotide is composed of one molecule of a pentose sugar, one molecule of a nitrogenous base, and phosphoric acid. The pentose sugars are ribose (RNA) and deoxyribose (DNA) and the nitrogenous bases are purines and pyrimidines.

DNA or deoxyribonucleic acid or RNA or ribonucleic acid is a polymer compound in which nucleotide units are linked repeatedly to form large chains.

Nucleic acid is a type of important organic compound that forms the nucleus of cells. The nucleus is important for the production and transmission of various codes from the association between chromosomes. Nucleic acids are organic compounds associated with protein synthesis in the cytoplasm.

1. Nitrogen reducing alkali;
2. Five-carbon sugars or pentose sugars; 3. Phosphate (PO4)

DNA is found in the nucleus, especially in chromosomes (chromatin), and has the characteristic chemical properties of genes, which are biological compounds that control and transmit the heredity of organisms and cells.

RNA synthesizes proteins inside the cell in a complex manner, and here too DNA has a special role in producing codes or specific messages.

DNA is located in the chromosomes of cells and RNA is found in the cytoplasm. The structure of these acids is very complex. It consists of three units. There are two types of alkalis namely nitrogen forming. Namely-purine bases: adenine (A) and guanine (G).
(b) Pyrizidine bases: Cytosine (C), Thymine (T) and Uracil (U). Nucleic acids contain two types of pentose sugars. Namely- 1. Ribose sugar and 2. D-oxyribose sugars.

^{Credit :
Madam Rita Parvin, Sir Shamol Shordar, Sir MD Rafikul Islam, Sir Shafiullah Shopon}

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