The term biochemistry was first introduced in 1903 by Karl Neuber, a German chemist. Since then, biochemistry has progressed, especially since the mid-20th century, with the advent of new techniques such as chromatography, X-ray diffraction, electrophoresis, RMI (nuclear magnetic resonance, NMR), radioisotope labeling, electron microscopy, and molecular dynamics simulations. . These techniques then enable the discovery and deeper analysis of various molecular and cellular metabolic pathways, such as glycolysis and the Krebs cycle. Let’s take a closer look at the following explanation of Biochemistry, Sinaumed’s:
What is Biochemistry
Biochemistry is a field of science that studies the knowledge of the structure, function and interactions of biomolecules that make up cells, reaction mechanisms of enzyme catalysis, energetics and cell metabolic reactions, signal transduction processes related to the biological and physiological functions of cells at the molecular level and genetic information.
History of the Development of Biochemistry
The biochemical renaissance began with the discovery of the first enzyme molecule, diastase, in 1833 by Anselme Payen. In 1828, Friedrich Wöhler published a book on the synthesis of urea, which proved that organic compounds could be made independently. Biochemistry also deals with the functions of molecules, elements, and chemical molecules found in living organisms, their functions, amounts and ratios, and how they interact with each other which are discussed in Biochemistry books.
This discovery is contrary to the understanding that believes that organic compounds can only be made by organisms. The development of new sciences such as bioinformatics also helps a lot in forecasting and modeling the structure of giant molecules. Today, biochemical discoveries are used in a variety of fields, from genetics to molecular biology and from agriculture to medicine. Learn more in the book Health Analysis Practicum Biochemistry which discusses basic theory, reactions, and practice questions.
The first application of biochemistry was probably in the manufacture of bread using yeast, some 5000 years ago. Another important discovery in the field of biochemistry is the discovery of genes and their role in transferring information within cells. This part of biochemistry is sometimes also called molecular biology. Next:
- In the 1950s, James D. Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins discovered how the structure of DNA and tried to find its relationship with the transfer of genetic information.
- In 1958, George Beadle and Edward Tatum won the Nobel Prize for their research on fungi which showed that one gene produces one enzyme.
- In 1988, Colin Pitchfork was the first person to be convicted of a crime through DNA evidence.
- More recently, Andrew Z. Fire and Craig C. Mello won the Nobel Prize in 2006 for discovering the function of RNA interference (RNAi).
Learn various basic biochemical concepts systematically at the theoretical and practical levels through the book Biochemistry Concepts and Practice Questions by Dr. Yohanis Ngili, M.Sc.
What are Biomolecules?
Biomolecules are simple organic compounds that form living organisms and are characteristic as products of biological activity.
In understanding various molecular aspects in an integrated manner, Sinaumed’s can read the book Biomolecular: For Basic Medical Science by Abdillah Imron Nasution which is below.
Many biological molecules are “polymers.” In this case, monomers are macromolecules that are relatively small and combine together to form macromolecules, which are also called “polymers”. When many monomers combine to synthesize a biological polymer, they then go through a process known as dehydration synthesis. There are four main classes of molecules in biochemistry, namely:
Carbohydrates or Charcoal Hydrates are nutrients whose main function is to produce energy, where each gram produces 4 calories. Humans need energy as fuel for activities and most of this energy is met by the process of carbohydrate metabolism. In a series of reactions for the process of carbohydrate metabolism against a catalyst that works very specifically which you can study in detail in the Biochemistry book below.
Although fat produces more energy, more carbohydrates are consumed daily as a staple food, especially in developing countries. In developing countries carbohydrates are consumed around 70-80% of total calories, even in poor areas it can reach 90%.
Whereas in developed countries carbohydrates are consumed only about 40-60%. This is because food sources that contain carbohydrates are cheaper in price than food sources that are rich in fat or protein.
Lipids are usually formed from one molecule of glycerol joined to another molecule. In triglycerides, there is one mole of glycerol and three molecules of fatty acids. In this case, the fatty acids are monomers. Lipids, especially phospholipids, are also used in some pharmaceutical products, for example as solvents (eg in parenteral infusions) or as components of drug carriers (eg in liposomes or transfersomes).
Proteins are very large molecules-or macro-biopolymers that are composed of monomers called amino acids. There are 20 standard amino acids, each consisting of a carboxyl group, an amino group, and a side chain (referred to as an “R” group). This “R” group is what makes each amino acid different, and the characteristics of this side chain will have an overall effect on a protein.
When amino acids join, they form special bonds called peptide bonds through dehydration synthesis, and become polypeptides, or proteins. Learn more about this in the book Protein – The Easy & Uplifting Biochemistry Series.
Nucleic acids are the molecules that make up DNA, a very important substance used by all cellular organisms to store genetic information. The most common types of nucleic acids are deoxyribose nucleic acid (DNA) and ribonucleic acid (RNA). The monomers are also called nucleotides. The most common nucleotides include adenine, cytosine, guanine, thymine, and uracil. Adenine pairs with thymine and uracil, thymine pairs only with adenine, while cytosine and guanine can only pair with each other.
Monosaccharides (mono- meaning ‘one’, -saccharides meaning ‘sugar’) are the simplest form of carbohydrates consisting of one sugar. In their structure, monosaccharides contain an aldehyde group (this group is called an aldose) or a ketone group (this group is called a ketose). Monosaccharides with three carbon atoms are called trioses, if four carbon atoms are called tetrose, five are called pentoses, six are called hexoses, and so on. Examples of monosaccharides are glucose, fructose, galactose, ribose, and deoxyribose. When consumed, glucose and fructose have different rates of gastric emptying, are absorbed differently, and have different metabolic fates, opening up many opportunities for the two types of saccharides to affect food intake differently. Most of the saccharides are used as fuel for cellular respiration. Disaccharides are formed when two monosaccharides form a glycosidic bond by removing a water molecule. One disaccharide molecule can also be separated into two monosaccharide molecules by hydrolysis. Examples of disaccharides are sucrose, maltose, and lactose. Polysaccharides are monosaccharides polymerized into complex carbohydrates. Examples are starch, cellulose, and glycogen. Polysaccharide molecules are generally large and often have complex branched connectivity. The shorter polysaccharides, with 3 to 10 monomers are called oligosaccharides. Polysaccharides are monosaccharides polymerized into complex carbohydrates. Examples are starch, cellulose, and glycogen. Polysaccharide molecules are generally large and often have complex branched connectivity. The shorter polysaccharides, with 3 to 10 monomers are called oligosaccharides. Polysaccharides are monosaccharides polymerized into complex carbohydrates. Examples are starch, cellulose, and glycogen. Polysaccharide molecules are generally large and often have complex branched connectivity. The shorter polysaccharides, with 3 to 10 monomers are called oligosaccharides.
Did you know, Sugar is a carbohydrate, but not all carbohydrates are sugar. There are more carbohydrates on earth alone than any other biomolecule. Carbohydrates are composed of monomers known as monosaccharides. Examples of monosaccharides are glucose (C6H12O6), fructose (C6H12O6), and deoxyribose (C5H10O4). When two monosaccharides go through a dehydration synthesis process, water is formed, because two hydrogen atoms and one oxygen atom are released from the two monosaccharide hydroxyl groups. Types of carbohydrates include:
The simplest type of carbohydrate is the monosaccharide, which usually consists of carbon, hydrogen, and oxygen atoms, usually in a 1:2:1 ratio (the general formula is CnH2nOn, where the smallest n is 3). Glucose, one of the most important carbohydrates, is an example of a monosaccharide. It also includes fructose, the sugar usually found in sweet fruits. Some carbohydrates (especially after condensation into oligo- and polysaccharides) have relatively lower carbon numbers than H and O. Monosaccharides can be grouped into aldoses (having an aldehyde group at the end of their chain, for example glucose) and ketoses (having a ketone group at the end of their chain, for example fructose).
Two monosaccharides can be joined together by dehydration synthesis. Thus, one hydrogen atom and one hydroxyl group (OH-) will be released. Hydrogen and hydroxyl atoms will combine and form water molecules (H-OH or H2O), hence the name “dehydration”. This new molecule is called a “disaccharide”. The reaction can also be reversed (breakdown reaction), by using one water molecule to break down one disaccharide molecule, it will break the glycosidic bond in the disaccharide. This reaction is called hydrolysis. The best known type of disaccharide is sucrose or what we usually know as cane sugar. One sucrose molecule consists of one glucose molecule and one fructose molecule. Other disaccharides, such as lactose, consist of one molecule of glucose and one molecule of galactose. inside the body, It is known that the enzyme lactase breaks down lactose into glucose and galactose. Usually, in elderly people, less lactase production and the result is lactose intolerance.
Oligosaccharides and Polysaccharides
When several (about 3-6) monosaccharides are joined together, they are referred to as oligosaccharides (oligo- meaning “a few”). If many monosaccharides are joined together, it is called a polysaccharide. Monosaccharides may combine to form one long chain, or may branch. The two best known types of polysaccharides are cellulose and glycogen, both of which are composed of glucose monomers.
- Cellulose is made by plants and is an important component that forms cell walls. Humans cannot make or digest cellulose.
- Glycogen, or muscle sugar as it is also known, is used by humans and animals as a source of energy.
Use of Carbohydrates as an Energy Source
Glucose is the main source of energy for living things. For example, polysaccharides are broken down into their monomers (glycogen phosphorylase removes glucose residues from glycogen). Disaccharides such as lactose or sucrose are broken down into their 2 monosaccharide components.
Glucose will be digested in the body in respiration reactions. The first step in the respiration reaction is glycolysis. The stages of glycolysis start from one glucose molecule until the final stage will produce 2 pyruvate molecules. This stage will also produce 2 ATP and give two electrons and one hydrogen to NAD+ to become NADH. This stage does not require oxygen. If the supply of oxygen in the body is not sufficient, NADH will be used to convert pyruvate into lactic acid (in the human body) or into ethanol and carbon dioxide.
In aerobic respiration, when cells receive enough oxygen, the pyruvate produced from the glycolysis stage will be digested again and converted into Acetyl Co-A. Pyruvate will remove one of its carbon atoms (to become carbon dioxide) and will give its electrons again to NAD+ to become NADH. 2 Acetyl Co-A molecules will enter the Krebs cycle stage, and will produce another 2 ATP, 6 NADH molecules, and 2 ubiquinone (FADH2), and carbon dioxide. The energy in NADH and FADH2 will later be used in electron transport. This energy is used by gradually releasing electrons and H+ from NADH and FADH2 in the electron transport system. The electron transport system will pump H+ out of the inner mitochondrial membrane. H+ concentration outside the mitochondrial inner membrane will cause a proton gradient,
In vertebrate bodies, striated muscles that are forced to work hard (for example when lifting weights or running), will not get enough oxygen so they will carry out anaerobic metabolism, which will convert glucose into lactic acid. The liver will re-produce the glucose, through a process called gluconeogenesis. The process of gluconeogenesis actually requires 3 times more energy than is produced in the process of glycolysis (there are 6 ATP made, whereas glycolysis only produces 2 ATP).
Like carbohydrates, some proteins also have vital functions in the body. For example, the movement of the proteins actin and myosin play a role in striated muscle contraction. One of the characteristics of most proteins is that they can only bind specifically, only one particular molecule or one group of molecules, so they are very selective. An antibody is an example of a protein that can only bind to one type of molecule. One of the most important types of protein are enzymes. Enzyme molecules can only recognize one type of reactant molecule, this reactant is called a substrate. Enzymes will catalyze the reaction, so the activation energy will decrease, and the reaction speed can take place up to 1011 times faster. A reaction might take 3,000 years to completely complete, but with enzymes it might be less than a second. The enzymes themselves are not used in the reaction process, so they will directly catalyze other substrates. Basically, proteins are made up of chains of amino acids. An amino acid consists of one carbon atom bonded to four groups. The first group is an amino group, —NH2, the second group is a carboxylic acid, —COOH (although they exist as —NH3+ and —COO− under physiological conditions). The third group is the hydrogen atom. The fourth group is usually abbreviated as “—R”, and it is this group that differentiates between amino acids. An amino acid consists of one carbon atom bonded to four groups. The first group is an amino group, —NH2, the second group is a carboxylic acid, —COOH (although they exist as —NH3+ and —COO− under physiological conditions). The third group is the hydrogen atom. The fourth group is usually abbreviated as “—R”, and it is this group that differentiates between amino acids. An amino acid consists of one carbon atom bonded to four groups. The first group is an amino group, —NH2, the second group is a carboxylic acid, —COOH (although they exist as —NH3+ and —COO− under physiological conditions). The third group is the hydrogen atom. The fourth group is usually abbreviated as “—R”, and it is this group that differentiates between amino acids.
The term lipid refers to a diverse group of molecules, including those that are poorly soluble in water, such as waxes, fatty acids, and their derivatives, such as phospholipids, sphingolipids, glycolipids, and terpenoids. Some lipids are linear aliphatic molecules, but some have a ring structure. Some are also aromatic molecules, and some are soft. Some lipids are polar although most of them are nonpolar or hydrophobic. However, some parts of its structure are hydrophilic or “water-loving”, thus making the molecule amphiphilic (has both hydrophobic and hydrophilic properties). In the case of cholesterol, the polar group is simply -OH (hydroxyl or alcohol). In the case of phospholipids, the polar group is larger so it is considered polar. Lipids are one of the important elements in the body. Most of the oil and dairy products we use to cook and eat such as butter, cheese and ghee are composed of fat. Foods that contain fat, when digested in the body it will be broken down into fatty acids and glycerol.
Nucleic acids are complex biochemical macromolecules, consisting of nucleotide chains that store genetic information. The most common types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic acids are found in all types of living cells and viruses. Aside from being a repository of genetic information, nucleic acids also play a role in delivering second messages, as well as forming the basic molecule for adenosine triphosphate. The monomers of nucleic acids are called nucleotides, and each nucleotide consists of 3 components:
- Nitrogenous bases (purines and pyrimidines)
- Pentose sugars or 5-carbon sugar compounds
- Phosphate group
Different types of nucleic acids can be found in the types of sugars in the chain (for example, DNA is made up of 2 deoxyribose). Also, the types of nitrogenous bases that may be present in nucleic acids can also differ: adenine, cytosine, and guanine can be present in both RNA and DNA, thymine only in DNA, and uracil only in RNA.