• Biochemistry,  Cell biology

    OXIDATIVE PHOSPHORYLATION, ELECTRON TRANSPORT CHAIN

    OXIDATIVE PHOSPHORYLATION It is the main source of energy of our cell. Takes place in Mitochondria. Movement of protons through inner mitochondrial membrane leads to ATP production DEFINITION Oxidative phosphorylation includes the coupling of the oxidation of NADH or FADH2 by the respiratory chain with the synthesis of ATP via gradient of protons across the inner mitochondrial membrane. ELECTRON TRANSPORT CHAIN An electron transport chain consists of a properly arranged & oriented set of electron carriers transporting electrons in a specific sequence from a reduced nicotinamide coenzyme (NADH) or a reduced flavin prosthetic group (FADH2) to molecular O2. Transport chain called the mitochondrial respiratory chain, which forms the final path for electron…

  • Biochemistry

    PLANT TISSUES

    Organs such as stem, roots in plants made up of different kinds of tissues. A tissue is a group of cells with a common origin, structure and function.Their common origin means they are derived from the same layer of cells in the embryo. Being of a common origin, they are similar in structure and hence perform the same function. Many kinds of tissues organize to form an organ. Example: Parenchyma, collenchyma, xylem, and phloem are different tissues in plants. The study of tissues is called histology. The plant tissues are mainly of two types: Meristematic (Gk. meristos : dividing) Permanent (non-dividing) Meristematic tissues Composed of immature or undifferentiated cells without intercellular spaces.…

  • Biochemistry,  Q & A

    Q & A ON WATER AND MINERAL SALT

    Q1.  What is the approximate percentage (in mass) of water in the human body? Is this percentage expected to be larger in the adult or in the old individual?  Ans: Approximately 65% of the human individual mass is water. The brain, for example, has around 90% of water in mass, the muscles, 85%, and the bones have between 25% and 40% of water. Younger adult individuals have proportionally more water in mass than older individuals. Q2.  What are the main biological functions of water? Ans: Water is the fundamental solvent for chemical reactions of living beings; it is the main means of substance transportation in the cell and between cells…

  • Biochemistry,  Cell biology,  Genetics

    WHAT IS DNA?

    Deoxyribonucleic acid (DNA) is a molecule that carries most of the genetic instructions used in the development, functioning, and reproduction of all known living organisms and many viruses. DNA is a nucleic acid; alongside proteins and carbohydrates, nucleic acids compose the three major macromolecules essential for all known forms of life. DNA  stores instructions for making other large molecules, called proteins. These instructions are stored inside each of your cells, distributed among 46 long structures called chromosomes. These chromosomes are made up of thousands of shorter segments of DNA, called genes. Each gene stores the directions for making protein fragments, whole proteins, or multiple specific proteins. DNA is well-suited to…

  • Biochemistry

    VARIETY OF LIFE

    Q1)  Any attribute or descriptive phrase, referring to form, structure or behaviour of a specific organism for a particular purpose is: A) Expression B) Specificity C) Character D) Nature E) None of the above Q2) Which one of the following is an example of “Expression of character”? A) Petal length B) Stem thickness C) Corolla colour D) Sepals colour green E) Leaf shape Q3) Living organisms having fundamental similarity in their structure are studied under: A) Biochemistry B) Anatomy C) Homology D) Heterology E) Cytology Q4) From evolutionary point of view, flipper and wing are believed to resemble human: A) Hand B) Foot C) Fingers D) Arm E) Leg Q5)…

  • Biochemistry

    ENZYMES

    Q1) Enzyme is a Greek word which means: A) in virus B) in bacteria C) in fungi D) in yeast E) in humans Q2) Who discovered that certain molecules of ribonucleic acid also function as enzymes? A) Friedrich Wilhem Kuhne only B) Friedrich and Thomas Cech C) Thomas Cech only D) Sidney Altman & Thomas Cech E) Sidney Altman only Q3) Molecule of ribonucleic acid which functions as enzymes are called: A) Increase energy of activation of reaction B) Maintain energy of activation of reaction C) Lower down energy of activation of reaction D) No effect on energy of activation of reaction E) Highly increase energy of activation of reaction…