Module 2: Atoms and Molecules - BIO122 (BOTANY) PDF

BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers Learning Objectives At the end of the module, the student must be...

BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers Learning Objectives At the end of the module, the student must be able to: a. Describe atoms and molecules as the building blocks of life b. Identify the major biological polymers Time Frame: 5 hours INTRODUCTION In the previous lesson, you are already introduced to Botany including its definition, branches and its importance. In this module you will be introduced again to Atoms and Molecules. These two concepts play a very important role in science because it makes things possible to exist because basically, all matters on this planet including living things are made up of atoms and molecules. This module will help you understand more about atoms and molecules and its relevance to the study of plants. ACTIVITY Are you a plant lover? Have you taken care of plants? Go outside and have time with your plant. List down below the elements that plants needs to grow/survive. _________________ _________________ _________________ _________________ _________________ _________________ ANALYSIS From your answer above, what are their contributions in plants growth? Element 1_________________________________________________ ___________________________________________________ Element 2_________________________________________________ ___________________________________________________ Element 3_________________________________________________ ___________________________________________________ Element 4_________________________________________________ ___________________________________________________ 16 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers ABSTRACTION What is an ATOM? Atom is considered as the smallest unit in which all matter are made up of. Most of theatom is empty space. The rest consists of a positively charged nucleus of protons and neutrons surrounded by a cloud of negatively charged electrons. The nucleus is small and dense compared with the electrons, which are the lightest chargedparticles in nature. Electrons are attracted to any positive charge by their electric force;in an atom, electric forces bind the electrons to the nucleus. Atomic Model Each individual atom consists of smaller particles—namely, electrons and nuclei/nucleus. These particles are electrically charged, and the electric forces on the charge are responsible for holding the atom together. Attempts to separate these smaller constituent particles require ever-increasing amounts of energy and result in the creation of new subatomic particles, many of which are charged. As mentioned, each particles carries electrical charges, in the nucleus of an atom a positively charge particle called proton is present together with a no charge particle called neutrons which contain most of the mass of the atom. On the other hand, the particles that surrounds the nucleus are called electron which are long-lived particles present in all ordinary and naturally occurring atoms. Other subatomic particles may be found in association with these three types of particles. They can be created only with the addition of enormous amounts of energy, however, and are very short-lived. 17 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers What are Molecules? Molecules are formed when two or more atoms of the same or different element bonded together. These atoms are held together by chemical forces or chemical bonds. An atom is the smallest particle of a substance but cannot exist freely. Contrary to this,a molecules can be considered as the smallest particle of an element or of a compound which can exist alone or freely under ordinary conditions. When two or more atoms from elements bond, they form a compound. The tiniest particle of a compound is a molecule. Two hydrogen atoms bonded with one oxygen atom create a water molecule. Water is a common compound. Some compounds happen naturally, such as water molecules. People manufacture many other compounds. They create chemical reactions that either add orbreak apart molecules to produce everything from nylon fishing lines to deadly weapons. The Elements of Life THE human body contains around 60 detectable chemical elements, but only about 28 of these elements, known as essential elements, are believed to participate in the healthy functioning of the body. Depending on the concentration and dosage, the elements show 18 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers either beneficial or deleterious effects. Many elements which are essential for bacteria and plants are not necessarily essential for humans directly. These six elements (C, H, O, N, S and P) constitute around 98% of all atoms present in proteins, nucleic acids, carbohydrates and other biological molecules. Therefore, these six elements are called biogenic elements and they combine with each other to form molecules that are the building blocks of a body. Oxygen (O) Oxygen is the most abundant element in the earth’s crust. In the human body, more than half of the body mass is oxygen. In redox reactions, oxygen accepts the electrons, which lead to the production of ATP, the energy source for the cell function. Oxygen is responsible for cellular respiration in plants. This element plays a critical role in photosynthesis and is both stored for energy and released as a byproduct. All oxygen available on Earth comes from plants. Hydrogen (H) Hydrogen, along with carbon and oxygen, are the three primary elements plants use in the largest amounts, and they perform as the building blocks for plant growth. Hydrogen ions are vital in both aiding proton gradients to help drive the electron transport chain in photosynthesis, and for plant respiration. Hydrogen is necessary for building sugars and other molecules to produce glucose for plant energy. Carbon (B) The second most abundant element can form different types of chemical bonds with other carbon atoms and a wide range of elements to make a variety of chemical compounds. For example, the hydrocarbon chains in cell membranes amino acids, carbohydrates and nucleic acids predominantly comprise carbon. The structural components of most enzymes, organs and tissues are made of proteins and carbohydrates. During photosynthesis, CO2 combines with H2O molecules to produce glucose (C6H12O6) and O2 which are the two essential components for the survival of life on earth. 19 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers Nitrogen (N) More than 75% by volume of earth atmosphere consist of nitrogen gas. Nitrogen is an essential macronutrient for plant function and is a key component of amino acids, which form the building blocks of plant proteins and enzymes. Proteins make up the structural materials of all living matters and enzymes facilitate the vast array of biochemical reactions within a plant. Nitrogen is also a component of the chlorophyll molecule, which enables the plant to capture sunlight energy by photosynthesis, driving plant growth and grain yield. Nitrogen plays a critical role within the plant to ensure energy is available when and where the plant needs it to optimize yield. This crucial nutrient is even present in the roots as proteins and enzymes help regulate water and nutrient uptake. Sulfur (S) Sulfur is one of the essential nutrients that is required for the adequate growth and development of plants. Sulfur is a structural component of protein disulfide bonds, amino acids, vitamins, and cofactors. Most of the sulfur in soil is present in organic matter and hence not accessible to the plants. Anionic form of sulfur (SO42−) is the primary source of sulfur for plants that are generally present in minimal amounts in the soil. It is water-soluble, so readily leaches out of the soil. Sulfur and sulfur- containing compounds act as signaling molecules in stress management as well as normal metabolic processes. sulfur is a very important component of plant metabolism. Phosphorus (P) In most of the living organisms, phosphorus is present in the structural framework of DNA and RNA as phosphodiester linkages. Phosphorus plays a vital role in virtually every plant process that involves energy transfer. High-energy phosphate, held as a part of the chemical structures of adenosine diphosphate (ADP) and ATP, is the source of energy that drives the multitude of chemical reactions within the plant. When ADP and ATP transfer the high-energy phosphate to other molecules (termed phosphorylation), the stage is set for many essential processes to occur. 20 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers Biological Polymers Biological polymers are large molecules composed of many similar smaller molecules linked together in a chain-like fashion. The individual smaller molecules are called monomers. When small organic molecules are joined together, they can form giant molecules or polymers. These giant molecules are also called macromolecules. Natural polymers are used to build tissue and other components in living organisms. There are four basic kinds of biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids. These polymers are composed of different monomers and serve different functions. 1. Carbohydrates Carbohydrates are molecules composed of sugar monomers. They are necessaryfor energy storage. Carbohydrates are also called saccharides and their monomers are called monosaccharides. Glucose is an important monosaccharide that is broken down during cellular respiration to be used as an energy source. Starch is an example of a polysaccharide (many saccharides linked together) and is a form of stored glucose in plants. The figure above shows the most common monosaccharides: - glucose, fructose and galactose (six-carbon monosaccharides) - ribose and deoxyribose (five-carbon monosaccharides). Note that they are all named using the suffix –ose, which means sugar. 21 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers 2. Lipids: Water-insoluble molecules that can be classified as fats, phospholipids, waxes, and steroids. Fatty acids are lipid monomers that consist of a hydrocarbon chain with a carboxyl group attached at the end. Fatty acids form complex polymers such as triglycerides, phospholipids, and waxes. Steroids are not considered true lipid polymers because their molecules do not form a fatty acid chain. Instead, steroids are composed of four fused carbon ring-like structures. Lipids help to store energy, cushion and protect organs, insulate the body, and form cell membranes Lipid Structure – Saturated and Unsaturated Fatty Acids 3. Proteins: Biomolecules capable of forming complex structures. Proteins are composed of amino acid monomers and have a wide variety of functions including transportation of molecules and muscle movement. Collagen, hemoglobin, antibodies, and enzymes are examples of proteins. Protein Structure 22 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers The twenty amino acids (Building block of protein). 4. Nucleic Acids: Molecules consisting of nucleotide monomers linked together to form polynucleotide chains. DNA and RNA are examples of nucleic acids. These molecules contain instructions for protein synthesis and allow organisms to transfer genetic information from one generation to the next. 23 | P a g e  BIO122 (BOTANY) MODULE 2 Lesson 2: Atoms and Molecules Elements of life Major Biological Polymers APPLICATION/ ASSESSMENT Explain the relevance of the topic you have in this module to the study of plants which is Botany. Explain the importance of Atom and Molecules in plants. Closure Congratulations! You did a great Job! You have finished the activities and tasks for this module. Good Luck! Reference/s Echapare E. (March 2019). Introduction to Botany. Transformative Learning Module in Botany Module 1. https://www.researchgate.net/publication/331430118 Bertsch, G. F. , McGrayne,. Sharon Bertsch and Trefil,. James (2022, February 3). atom. Encyclopedia Britannica. https://www.britannica.com/science/atom https://youtu.be/LhveTGblGHY https://youtu.be/ooWfzpUIoNM https://youtu.be/C0Qaf-UJ2XQ https://www.thoughtco.com/biological-polymers-373562 24 | P a g e