Enroll Biology XI Sindh Board Course
Solutions of Chapter-01: Biomolecules Biology XI Sindh Board are prepared keeping the students’ needs and academic requirements in mind. These are based on the latest CBSE syllabus and provide in-depth analysis of the topics to help students secure better grades.
The chapter covers topics like chemical equation, balanced chemical equation, implication of a balanced chemical equation and types of chemical reactions. It also includes various exercises to help the students practice and understand the topic in a more efficient manner.
1. Biological Molecules
Biological molecules are the organic compounds that form a vital part of every living thing. They play a role in the maintenance of life from single-celled bacteria to human beings, and are responsible for growth, development, and reproduction.
They are made of carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, and additional minor elements. The largest molecules are called biological macromolecules, and they make up the bulk of a cell’s mass.
There are four major classes of biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids. These large biomolecules are the basis for cells and are essential to life.
Biological molecules are the building blocks of all life and make up the bulk of our bodies. These include carbohydrates, lipids, nucleic acids and enzymes.
Proteins are a class of highly complex organic molecules, each containing a string of amino acids linked together by what is called a covalent peptide bond. This is not to be confused with a noncovalent bond such as hydrogen sulfide (H2S).
Although proteins are abundant in our cells, they are still rather hard to visualize without the aid of a computer or microscope. However, thanks to x-ray crystallography and powerful nuclear magnetic resonance (NMR) techniques, we are now able to determine the structures of many of these marvels. The aptly named Molecular Medicine Center of Excellence in Rockville Maryland is one of the best places in the world to see this impressive technology in action.
Every day, living things go through trillions of chemical reactions in their cells. These reactions are critical for life.
Without enzymes, many of these reactions would take so long that they could not sustain a living organism. Enzymes, however, stabilize transition states and increase the rate of these important reactions.
Enzymes are protein polymers that catalyze biochemical reactions. They can be classified into six categories based on the type of reaction they carry out. These include oxidoreductases, transferases, hydrolases, lyases, isomerases and ligases.
4. Nucleic Acids
Nucleic acids are polynucleotides (long chainlike molecules) composed of a series of nearly identical building blocks called nucleotides. Each nucleotide consists of a nitrogenous base that is attached to a pentose (five-carbon) sugar and a phosphate group.
DNA and RNA are the two most important types of nucleic acids. Both are essentially biopolymers, macromolecules that form the basis for all known forms of life.
DNA and RNA are made from alternating phosphate and sugar units and contain purine and pyrimidine bases. Adenine and guanine are classified as purines, while cytosine and thymine are pyrimidines.
Biomolecules, or biological molecules, are the chemical structures found in living organisms. They are divided into two groups: inorganic (elements found largely in one organism) and organic (elements found in many organisms).
DNA is the largest of all the biomolecules. It consists of a double helix of long, thin strands called nucleotides. Each strand contains a sugar, a phosphate, and nitrogen bases that hold them together.
Each nucleotide is like a letter in a four-letter alphabet that carries genetic information, or “code.” Adenine, thymine, guanine, and cytosine are the four types of nitrogen bases.
In order to read the “code” of the DNA molecule, cells use a chemical procedure called translation. They arrange the nucleotide sequences of each DNA strand into three-nucleotide combinations, which they call codons.