Biochemistry

Biochemistry is a branch of science which deals with the chemical processes within and related to living organisms. It is a branch of science which brings together biology and chemistry. Biochemists can understand and solve the biological problem by using the chemical technology and knowledge of chemical science. The main focus of biochemistry is what’s going inside the cell. It also deals with the study of components of like protein, lipid and organelles.

Introduction of Biochemistry

Biochemistry also deals with the study of communication of cells during growth or fighting illness. This gives an idea of how the molecules will interact with the cells. Biochemistry includes a range of scientific disciplines such as microbiology, genetics, forensics, plant science and medicine.

Biochemists provide new ideas and experiments to understand how life works and biochemistry also helps to understand our health and disease. It contributes innovative information to the technology revolution. Biochemists work in many places such as hospitals, universities, agricultural firm, food institutes, cosmetic industry, forensic crime research, drug discovery and development. Biochemists also have many skills including research about new technology, various biological problems solving, planning biological surgeries.

Metabolism

Metabolic flow is mainly based on the anabolic and catabolic reactions. Metabolism is a biological process that begins with the ingestion of food which is foreign to the organism. When the smaller molecules are taken up into the organisms bloodstream an anabolic reaction occurs. But the catabolic phase breaks down the organism again for its functional needs.

In the anabolic reaction phase, large compounds are formed from smaller ones. In an anabolic reaction, chemical reductants play a predominant role. Formation of complex carbohydrates from lactate or carbon dioxide is an example of an anabolic reaction. On the other hand, the catabolic reaction is the opposite type of reaction which breakdowns of complex compounds to smaller compounds.

In a catabolic phase reaction, chemical oxidation and dehydrogenation play an important role. Conversion of glucose or glycogen to carbon dioxide is an example of the catabolic phase reaction. An anabolic reaction requires energy to carry out the whole process. This energy is mainly needed for the reaction process and also to hold together the complex structure which is formed by the smaller molecules.

But in case of a catabolic reaction, it breaks down the larger substances in the organism hence it freed up the energy. This free energy is used for muscle movement, to facilitate conduction in the nervous tissue, to enable the synthesis of biochemical substances.

Anabolic and catabolic reactions are mainly two opposite process but not completely the reverse of one another. Both the two reactions need different enzymes but they can take place in the same cell. Often they take place in different cells such as lipid anabolism in the cytosol and lipid catabolism in the mitochondrion. Both the two reactions have cyclic interaction.

Citric Acid Circle

Mainly the aerobic part of the metabolism process begins in the mitochondrion. There are eight steps in the citric acid circle and all the steps occur inside the mitochondrion. In the catabolic process, all the biochemical energies store in the form of adenosine triphosphate.

To complete the citric acid circle some energy-containing compounds have to go through oxidative phosphorylation in the inner mitochondrial membrane. The citric acid circle is the starting point of the gluconeogenesis. Acetyl-CoA is the starting molecule of the citric acid circle and it binds the end product oxaloacetate.  Acetyl- CoA is the main key molecule of metabolism.

Acetyl- CoA is the starting point of the fatty acid and cholesterol synthesis. In the body of plants and bacteria, acetyl- CoA can be converted to oxaloacetate and other intermediates of the citric acid circle. The glyoxylate pathway is not available in the mammal body system this is the reason they cannot live on a diet which contains only fat.

Photosynthesis of Plants

Photosynthesis of plants occurs in leaves of the green plants. It has two reactions light reaction and dark reaction. The light reaction occurs in the influence of the chlorophyll. Chlorophyll is a biochemical compound which is similar to the haemoglobin in the blood cell. The light reaction results in the oxidation of water and produces pure oxygen. These light reactions convert light energy to biochemical energy.

In the light reaction, light drives the transfer of a proton from one substance to another substance in the uphill direction. Dark reaction is the second phase of the photosynthesis. The dark reaction includes the fixation of carbon dioxide for the production of sugars.

The production of sugar is an anabolic reaction and the energy for this anabolic reaction comes from the ATP formed during the light reactions. The dark reaction produces disaccharides and polysaccharides. Dark reaction is not directly dependent on the light but the light reaction depends on the daylight and the chlorophyll helps to collect the light energy and distribute the energy for photosynthesis reactions.

Complex Carbohydrates

Complex carbohydrates or polysaccharides are available in nature as three main polysaccharides. Starch and cellulose are both typical plant polysaccharides. Starch forms as granules in plant cells. The starch has alpha- glycosidic bonds which link all glucose molecules together.

Helix is the simplest form of glucose. Starch is the major energy source of the living worlds. Similarly, cellulose is the main component of the cell of the wall of plants. Beta-D- glucose with Beta –glycosidic linkage forms cellulose. Glycogen is mainly found in certain types of cell-like liver and muscle as granules form.

Normally it is not found in heart or brain cells. In glycogen alpha-glycosidic linkages connect the glucose molecules together. Covalent bonding is the main linkage bonding in the complex carbohydrates. The primary structure of a protein is made off peptide bonds.

Hydrogen bonding allows a more stable structure in complex carbohydrates and also in proteins. Hydrophobic interactions occur spontaneously and play a predominant role in the lipid structure. Lipids structures have no monomer or polymer. All they have energized form of acetate as acetyl-CoA. Lipids also have the possibility to form secondary structures in the form of a membrane.

FAQs about Biochemistry

Q.1 Name three amino acids containing nonpolar, aliphatic R groups.

Answer:  Amino acids containing nonpolar, aliphatic R groups are Glycine, Alanine, leucine.

Q.2: Write the differences between DNA and RNA.

Answer: DNA is a long polymer and it has deoxyribose and phosphate backbone. It has four distinct bases thymine, adenine, cytosine and guanine. RNA is a polymer with ribose and phosphate backbone. It has also four bases uracil, cytosine, adenine and guanine. The location of DNA is the nucleus of the cell and mitochondria. Location of RNA is the cytoplasm, nucleus and ribosome. The sugar portion of DNA is deoxyribose and the sugar portion of RNA is ribose. DNA is a double standard molecule but RNA is a single standard molecule. DNA is self-replicating but RNA cannot self-replicate.

The nitrogen base pairing of DNA is guanine, cytosine and adenine, thymine. The nitrogen base pairing of RNA is guanine, cytosine and adenine, uracil. Types of DNA are A-DNA, B-DNA, C-DNA, D-DNA, Z-DNA. Types of RNA are m-RNA, t-RNA, rRNA, sn-RNA. The helix geometry of DNA is of Beta- form and the helix geometry of RNA are of alpha-form. DNA is more stable than RNA. In alkaline conditions DNA is stable. Unusual bases never present in DNA but it may be present in RNA.