Biochemistry Lecture 1 PDF

Biochemistry lecture 1 Dr. Hussein Al. Robaav INTRODUCTION TO BIOCHEMISTRY: Definition: Biochemistry can be defined as the science concerned with the chemical basis of life. BIO LIFE (Greek) The cell is the structural unit of living systems. Thus, biochemistrycan also be described as: The s...

Biochemistry lecture 1 Dr. Hussein Al. Robaav INTRODUCTION TO BIOCHEMISTRY: Definition: Biochemistry can be defined as the science concerned with the chemical basis of life. BIO LIFE (Greek) The cell is the structural unit of living systems. Thus, biochemistrycan also be described as: The science concemed with the chemical constituents of living cells and with the reactions they undergo. In biochemistry, we are interested in the chemical structure and reactions in living cells. So, the introduction for biochemistry is the study of the living cell. Biochemistry is the application of chemistry to the study of biological processes at the cellular and molecular level. It emerged as a distinct discipline around the beginning of the 20 th century when scientists combined chemistry, physiology and biology to investigate the chemistry of living systems by I- Studying the structure and behavior of the complex molecules found in biological material 2- The ways these molecules interact to form cells, tissues and whole organism Relationship of biochemistry is essential with all life sciences Genetics: The biochemistry of the nucleic acids lies at the heart of genetics. Physiology: The study of body function, overlaps With biochemistry almost completely. Immunology employs numerous biochemical techniques..PharmacoIogy and pharmacy rest on a sound knowledge of biochemistry and physiology; in particular, most drugs are metabolized by enzyme-catalyzed reactions. Toxicology: Poisons act on biochemical reactions or processes. Pathology (the study of disease) : Biochemical approaches are being used increasingly to study basic aspects ofsuch as inflammation, cell injury, and cancer. 1  Biochemistry lecture 1 Dr. Hussein Al. Robaay The origin of Life The Earth is 4,500 million years old, as judged by several corroborating radionuclide studies of the oldest rocks on the planet show. Meteoric bombardmentof the proto- Eatth continued heavily until 4,000 MY A, probably precluding life during this the period. The majority of the oldest rocks on Earth are 3,500 million years old, and of about earliest microfossils are from 3,000+ MY A, hence we only have a window of 500 million years from the end of the meteoric bombardmentto the first signs certainty! microbial life. This means we are either very lucky, or life is a high-on thought that the What did life use as its raw materials? Early theories of life's origins seems earth had a reducing atmosphere (i.e., lots of ammonia and methane) but this proceeded. less likely now, as our understanding ofearly Earth chemistry has The matter and Elements in living cells The matter is anything that has mass and volume (occupies space). -In chemical point of view matter is made up of atoms. and circulating -Atoms are formed from nucleus (having protons and neutrons) negatively charges electrons. -Atoms having specific numbers Of protons form elements -There are 118 elements on the periodic table 92 ofthe mare natural. -All living and non-living matter are made ofelements. -Group of elements can form molecules of compounds Living matter consists of some chemical elements. Those ekments bind together to form molecules. Most Of compounds in Biological systems are organic compounds participate (have Carbon) Chemical compounds have reactive functional groups that in biological structure and biochemical reactions. Polymerization of organic molecules form more complex structure by the mean of condensation reaction with the removal of water. The key Of origin Of living matter is thc formation of membranes that separate the critical molecules required tor replication and energy capture. Larger polymers of molecules form macromolecules that all together provide biological specificity of the living matter. E.g. carbohydrates, proteins, lipids, genetic nuterial (DNA and RNA) etc. Biological Hierarchy: Simple Molecules are used to Build Complex Structures. There are many classifications of elements regarding its distribution in living cells. The most used one is as follow: 2  Biochemistry lecture Dr. Hussein Al. Robaay LIC H N O P S: are the most abundant elements in cell. Collectively referred to with the acronym (SPONCH) DThey account for more than 99% of atoms in the human body C]H,O, N and C have common properties that are important to the chemistry of life. OThey all: have relatively low atomic numbers capable of forming one, two, three and four bonds (for H, O, N and C ,in order).form the strongest covalent bonds in general. THE HUMANBODY 16 18% Carton sulfur. sodjgtn Chlorine0.2% Atl%i Monomers and Polymers structure Monomers are relatively small molecules that are linked together to create large macromolecules, which are known as Polymers Biomolecules: The four main classes of molecules in biochemistry are: carbohydrates, lipids, proteins, and nucleic acids. Biomolecules to Cells There are a few critically important small molecular precursors to biomolecules found in the environment. Biomolecules can be looked at in two major categories: small molecules and macromolecules. The small molecules are going to be either metabolites or monomers from which the macromolecules are built. First let's note the "inorganic" (sometimes called mineral) molecules and molecular ions: oxygen (02), water (H20)' carbon dioxide (C02), ammonia or alnmonium ion 3  Biochemist lectur (NH3 or NH4+), nitrate ion (N03-), nitrogen (N2), phosphate ion (P043-) and sulphate ion (S042 ). 11tesc are nu»stly metabolites, though the ions can also serve as counter ions along with chloride in creating the intracellular media. These molecules and ions In turn can be made into metabolites, small organic mleeules used in energy transformation and as precursors to monomers and macromo lecu les. The monomers and the associated macromoleculesare divided into four major categories: I- Carbohydrates are made from monomers called monosaccharides. Examples of these monosaccharide include glucose (C6HJ206), fructose (C5H1206). 2- Lipids are usually made from one molecule of glycerol combined with other molecules. For example in triglycerides, the main group of bulk lipids, there is one molecule of glycerol and three fatty acids. 3- Proteins are very large molecules made from monomers called amino acids. There are 20 standard amino acids.. 4- Nucleic acids are the moleculesthat make up DNA, (to store their genetic information.(Themost common nucleic acids are Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA). Many Important Biomoleculesare Polymers lipids proteins carbo nucleic acids Note that all of these families of molecules exhibit chirality's in some, and generally most, of their members. Also, biological systems chose a single chirality for each family (e.g., L-amino acids, D-sugars) All of these molecules together go to make up cells Elements*Molecule *Cell *Tissue *Organ *Organism *Population *Species *Biosphere 4