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Biological molecules are a variety of substances that play an essential role in the lives of living organisms. They include carbohydrates, lipids, proteins and nucleic acids.
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Carbohydrates
Carbohydrates are organic compounds that contain carbon covalently bound to other atoms, often in the ratio of 2:1, hence the general formula (CH2O)n. They are a major group of biomolecules in living organisms, and they serve as the body’s energy source, structural support, and for cell recognition.
The most fundamental type of carbohydrate is a monosaccharide, which contains one single sugar unit. It can combine with other sugars to form more complex types called oligosaccharides, which consist of three to ten simple sugar units.
These polysaccharides are formed by a dehydration synthesis process in which two or more monosaccharides join together in glycosidic bonds to form a long chain of saccharide units. The resulting complex carbohydrates, including starch and glycogen, provide the energy needed by living organisms.
The sugars in carbohydrates are the basis of many chemical reactions in the body. These include ATP (adenosine triphosphate) synthesis, cellular respiration, and glycolysis. They also serve as the building blocks for proteins, lipids, and nucleic acids.
Proteins
Getting a solid handle on the biomolecules that make up our bodies is no easy feat. These include the big five – proteins, nucleic acids, carbohydrates, lipids and water minerals (ions). The most impressive part of all these critters is that they work together as one. In short, they are the brains behind our well-being and health.
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Nucleic Acids
Biological molecules are the major components of living organisms. These include proteins, carbohydrates, lipids, and nucleic acids. These biological molecules perform a variety of functions in the body and help to sustain life.
Nucleic Acids are a group of large molecules consisting of repeating units of nucleotides that direct cellular activities such as cell division and protein synthesis. Each nucleotide consists of a sugar molecule, a nitrogenous base, and a phosphate group.
DNA (deoxyribonucleotide) is composed of a pentose sugar, phosphoric acid, and nitrogen-containing bases. These bases are of two types: pyrimidine and purine.
These bases are placed regularly along the DNA molecule at a distance of 3.4 A. The pyrimidine bases are single-ring nitrogenous bases and the purine bases are double-ring nitrogenous bases. They are essential to the structure and function of DNA.
Lipids
The biomolecules are organic molecules that occur in living organisms. These molecules perform many important functions such as storing energy, signaling and acting as structural components of cell membranes.
Lipids are a class of hydrophobic and nonpolar molecules that store and release energy through a process called oxidation. Examples include fats, oils and waxes.
They are often used as a source of energy, but some lipids serve as structural components of cell membranes or help in the transport of nutrients within cells. Some lipids are also used as a source of hormones or as an important signaling molecule.
In most cases, lipids are insoluble in water but can be dissolved in nonpolar solvents. However, there is a danger that a simple definition of lipids based on their solubility may lead to confusion and misunderstanding.