general biology ppt chapter 1-2 (1).pptx freshman course

General Biology PowerPoint freshman course chapters one and two

1. 2 General Biology (Biol. 1012) Objectives Explain the scope of biology and molecular basis of life Describe life activities from the cellular point of view Manipulate basic biological tool, record data and draw conclusions Develop scientific attitude, skill and conduct biological experiments using scientific procedures Outline basic processes of energy transduction and synthesis of intermediate or final products in living cells Understand the basic concepts of genetics and inheritance

2. 3 Chapter One : Introduction Biology is the scientific study of life and living organisms , encompassing their structure, function, growth, evolution, distribution, and taxonomy. The term biology is derived from the Greek words " bios " (life) and " logos " (study) term Biology was coined by Pierre-Antoine de Monet and Jean-Baptiste de Lamarck in the late 1700s. Initially, Biology focused mainly on Botany and Zoology , but as time went on, the field grew to include many new branches and technologies. But new technologies developed in pure subjects as well as in applied fields, which gave rise to a very broad concept of science called Biological Sciences .

3. 5 1.2. The origin and nature of life The origin of life refers to the process by which lifeforms first arose on Earth . Life is typically characterized by the ability to grow, reproduce, maintain homeostasis, respond to stimuli, and evolve over time. The first living things to appear were the simplest creatures, single- celled organisms , these came more complex, multi- cellular organisms.

4. Characteristics of life Cellular organization : All living organisms consist of one or more cells. Metabolism : Conversion of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Growth and Reproduction : Ability to reproduce and pass genetic information to offspring. Response to Stimuli : Ability to respond to environmental changes. Adaptation through Evolution : Changes over time to adjust and survive in their environment.

5. 1. Theory of Special Creation This theory posits that life was created by a supernatural entity or divine force at some point in the past . this theory aligns with religious and cultural beliefs , providing a spiritual explanation for the origin of life rather than empirical scientific evidence. Offers a straightforward explanation for the complexity and diversity of life without the need for understanding complex scientific concepts. Does not offer testable or falsifiable hypotheses and is not supported by genetic evidence indicating the evolution of species over time. Theories on Origin of life

6. 2. Theory of Spontaneous Generation: Also known as abiogenesis this theory suggests that life arose from non-living matter, such as mud or rotting material, spontaneously. Historically observed phenomena, such as maggots appearing on decaying meat, were misinterpreted to support this theory. Experiments by Louis Pasteur and others conclusively disproved spontaneous generation for macroscopic life, showing that life comes from pre-existing life. It does not stand up to the modern understanding of biology and is no longer considered scientifically valid.

7. inquiry is based on the belief that the Bible is to be accepted as a completely accurate accounting of all about which it speaks. Scientists , on the other hand, utilize what they call the scientific method , which allows them to test hypotheses and theories and to develop concepts and ideas. 9 3. Theory of Catastrophism : This theory modifies the Theory of Special Creation by suggesting that life has been created multiple times by God following major catastrophes like geological disturbances. Each catastrophic event supposedly wiped out existing life forms, leading to the creation of entirely new species. Supported by observations of sudden changes in the fossil record and geological strata . Aligns with the evidence of sudden changes in the fossil record coinciding with catastrophic geological events. Does not explain the gradualism observed in the fossil record or the mechanism of species change and adaptation. Implies that life's diversity arises in fits and starts, rather than as a continuous process.

8. 4. Cosmozoic Theory (Theory of Panspermia) : Suggests that life exists throughout the Universe and was spread to Earth through space, perhaps by meteorites, comets, or cosmic dust. Finds some support in the discovery of organic molecules in space and microorganisms that can survive extreme conditions. Does not explain the origin of life itself but rather the distribution of life in the Universe . The survivability of microorganisms during space travel is also still under investigation. Proposed by Richter in 1865 and later supported by Arrhenius in 1908 Some microorganisms can survive harsh space-like conditions, suggesting life could travel through space. While organic molecules have been found in space, there is no direct evidence of living organisms being transported to Earth.

9. Theory of Chemical Evolution : Also known as the Materialistic or Physico -chemical Theory this suggests that life on Earth began through a slow and gradual process of chemical evolution around 3.8 billion years ago. proposed by A.I. Oparin and J.B.S. Haldane in the early 20th century. life evolved from simple organic molecules through chemical reactions driven by Earth's early environmental conditions. While it explains the formation of life's building blocks, it does not fully elucidate the complexity of the transition from non-living chemistry to living cells. Fits well with the principles of natural selection and biological evolution, providing a continuous process from chemistry to biology.

10. 12 The Nature and Characteristics of Life Life is a unique condition that sets living organisms, including animals and plants, apart from inorganic matter and deceased entities. It encompasses a series of processes that sustain a state of existence. Amongst the plethora of life forms, humans are considered the most complex, prompting an exploration into the multifaceted nature of human life and death. Humans exhibit three dimensions of existence: Physical Life : This is the fundamental state of being, grounded in our bodily existence. Mental Life : The mind enhances our capabilities and extends the reach of our activities. Spiritual Life : The spirit elevates our existence to its highest potential, enabling what we might term 'maximized living'. Physiology : The physical manifestation of life is evidenced through a myriad of biological functions that maintain our corporeal presence

11. 1.3. Scientific methods are systematic approaches to inquiry used to investigate phenomena, acquire new knowledge, or correct and integrate previous knowledge. To ensure research is based on empirical and measurable evidence subject to specific principles of reasoning. It is an empirical method of acquiring knowledge. It is also the technique used in the construction and testing of a scientific hypothesis. The scientific method has five basic steps, plus one feedback step: Make an observation. Ask a question. Form a hypothesis , or testable explanation. Make a prediction based on the hypothesis. Test the prediction. Iterate : use the results to make new hypotheses or predictions. 13

12. Observation - Quantitative and qualitative measurements of the world. Inference - Deriving new knowledge based upon old knowledge. Hypotheses –A suggested explanation. Rejected Hypothesis - An explanation that has been ruled out through experimentation. Accepted Hypothesis - An explanation that has not been ruled out through excessive experimentation and makes verifiable predictions that are true. Experiment - A test that is used to rule out a hypothesis or validate something already known. Scientific Method - The process of scientific investigation. Theory - A widely accepted hypothesis that stands the test of time. Often tested, and usually never rejected . The scientific method is based primarily on the testing of hypotheses by experimentation. This involves a control, or subject that does not undergo the process in question

13. also seek to limit variable s to one or another very small number, single or minimum number of variables. The procedure is to form a hypothesis or prediction about what you believe or expect to see and then do everything you can to violate that, or falsify the hypotheses. Although this may seem unintuitive, the process serves to establish more firmly what is and what is not true. Summary of the scientific method Step 1: Observe behavior or other phenomena Step 2: Form a tentative answer or explanation (a hypothesis (guess a reason) Step 3: Use your hypothesis to generate a testable prediction Step 4: Make systematic, planned observations (data collection) Step 5: Results and Discussion , Use the observations to evaluate (support, refute, or refine) the original hypothesis Step 6: Conclusion Step 7: Recommendation 15

14. 16 Chapter Two : Biological Molecules A re R eferred to as the molecules of life (bio-molecules) that are basically found in a living cell and categorized as organic and inorganic molecules The organic biomolecules are proteins, carbohydrates, lipids and nucleic acids. They are important either structurally or functionally for cells and, in most cases, they are important in both ways. the most commonly known inorganic molecules are water and minerals, which are still important for the normal functioning of the cell.

15. 2.1. Carbohydrates: made of atoms of carbon, hydrogen and oxygen. They are an important source of energy and they also provide structural support for cells and help with communication between cells ( cell- cell recognition ). Based on the number sugar units they contain, they are categorized into three Monosaccharides e.g Glucose (dextrose), fructose ( levulose ), and galactose. Disaccharides E.g Polysaccharides Each of the sugar molecules are bonded together through the glycosidic linkage/s.

16. Monosaccharides are the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built. They are usually colorless, water-soluble, and crystalline organic solids. Most monosaccharides have the formula (CH2O)x, where x ≥ 3. are the building blocks of disaccharides (such as sucrose, lactose and maltose) and polysaccharides (such as cellulose and starch). aldehydes or ketones, or substances that yield these compounds on hydrolysis. Example: Glucose is aldehyde and fructose is Ketone.

17. 19 Glucose Is a simple sugar with the molecular formula C₆H₁₂O₆ primary source of energy for the body's cells. It is transported through the bloodstream and taken up by cells Its concentration in the blood is about 1 gdm - 3 . The small size and solubility in water of glucose molecules allows them to pass through the cell membrane into the cell. concentration of glucose in the blood is regulated by hormones such as insulin and glucagon . Insulin lowers blood glucose levels by facilitating the uptake of glucose into cells, while glucagon increases blood glucose levels by signaling the liver to release stored glucose.

18. Fructose a hexose sugar & has the same chemical formula as glucose but a different structure. It is found in fruits, honey, and root vegetables and is the sweetest of all natural sugars. In the human body, fructose is converted to glucose in the liver. Fructose is a ketose (a non- reducing sugar). Fructose reacts with glucose to make the dissacharide sucrose . Ribose and deoxyribose Ribose and deoxyribose are pentoses . The ribose unit forms part of a nucleotide of RNA . The deoxyribose unit forms part of the nucleotide of DNA .

19. 3 . Galactose: Similar to glucose in structure and another hexose sugar. It is not as sweet as glucose or fructose and is found in milk sugar (lactose) along with glucose. It is metabolized in the liver and is a component of several important biomolecules. Ribose : A five-carbon (pentose) sugar, a crucial part of ribonucleic acid (RNA) and several other biological molecules, including ATP and coenzymes. It is known for its role in forming the backbone of genetic material and energy molecules Mannose: Is a hexose sugar structurally similar to glucose but with a different arrangement of hydroxyl groups. It plays a role in human metabolism, particularly in the glycosylation of certain proteins.

20. Monosaccharides are used very quickly by cells. However, a cell may not need all the energy immediately and it may need to store it. Monosaccharides are characterized by the number of carbon atoms they contain: Trioses have three carbon atoms. Tetroses have four carbon atoms. Pentoses have five carbon atoms. Hexoses have six carbon atoms. Heptoses have seven carbon atoms. The monosaccharides can also be distinguished by their functional groups: Aldoses : Monosaccharides with an aldehyde group (-CHO) at the end of the molecule, such as glucose and galactose. Ketoses : Monosaccharides with a ketone group (C=O) in the middle of the molecule, such as fructose.

21. Disaccharides : are carbohydrates that consist of two monosaccharide residues linked by a glycosidic bond . When digested, disaccharides are hydrolyzed into monosaccharides before they can be absorbed by the body. Sucrose: This is the most well-known disaccharide, composed of glucose and fructose. It is commonly known as table sugar and is used extensively as a sweetener in the food industry. Sucrose is obtained from sugar cane or sugar beets. Sucrose or table sugar : composed of the monomers glucose and fructose. Sucrose is a non-reducing sugar. Lactose : Found in milk and dairy products, lactose is made up of glucose and galactose. It is broken down by the enzyme lactase, which is found in the intestines of mammals. Some adults have lactose intolerance, which means they do not produce enough lactase, leading to digestive problems when consuming dairy products.

22. Maltose: Maltose, or malt sugar, is composed of two glucose units. It is less sweet than sucrose and is produced when starch is broken down, as happens during the germination of seeds (such as barley) and in the digestive systems of humans. Maltose is important in brewing and in the production of certain foods and beverages. Trehalose : Is a natural sugar made of two glucose molecules. It is found in mushrooms, yeast, and certain invertebrates. Trehalose has the unique ability to protect organisms and cells from extreme environmental conditions like desiccation and freezing.

23. Polysaccharides : are long chains of monosaccharide units bound together by glycosidic linkages. They are complex carbohydrates and serve various functions in both plants and animals, including structural support, energy storage, and cell recognition. May be branched or unbranched Polysaccharides are classified based on their structure and function into three main types:

24. 1.Storage Polysaccharides : a.Starch : plant-based polysaccharide composed of two types of molecules, amylose and amylopectin . Both are made of glucose units, but amylose is linear while amylopectin is branched. Amylose is an unbranched chain of glucose monomers linked by α-1,4 glycosidic linkages, while amylopectin is a branched polysaccharide with α-1,6 linkages at the branch points. It is completely insoluble in water. Starch is the main form of stored carbohydrate in plants and is an important energy source for humans. b.Glycogen : referred to as animal starch, glycogen is a highly branched polysaccharide of glucose. It serves as a form of energy storage in animals, fungi, and bacteria. In humans, it is stored in the liver and muscles and is mobilized during times of energy need.

25. 2. Structural Polysaccharides: Cellulose: A major component of plant cell walls, Is a linear polysaccharide composed of β-glucose units. It provides structural support to plants and is the most abundant organic polymer on Earth. It is indigestible by humans but is an important dietary fiber which aids in digestion. While the β-1,4 linkage cannot be broken down by human digestive enzymes, herbivores such as cows, koalas, buffalos, and horses are able to digest plant material that is rich in cellulose with the help of specialized flora in their stomach . Chitin : Similar in structure to cellulose but with nitrogen-containing side groups, chitin is found in the exoskeletons of arthropods and the cell walls of fungi. It is a tough, protective biopolymer that also serves as a structural component.

26. 29 The properties of a polysaccharide molecule depend on Its length (though they are usually very long) The extent of any branching (addition of units to the side of the chain rather than one of its ends) Any folding which results in a more compact molecule Whether the chain is 'straight' or 'coiled'

27. 31 2.2. Lipids lipids are a broad group of organic compounds that are essential to our body as they are the structural component of the cell membrane, provide energy, produce hormones, help in the digestion and absorption of food, and play an important role in signaling. including fats, waxes, sterols, fat-soluble vitamins, and phospholipids. Fatty acids are made mostly from chains of carbon and hydrogen and they bond to a range of other types of atoms to form many different lipids. are insoluble in water but soluble in organic solvents why? A lipid called a triglyceride is a fat if it is solid at room temperature and an oil if it is liquid at room temperature. Fat cells are categorized in white fat cells and brown fat cells. Various types of lipids occur in the human body, namely 1) triacylglycerol, 2) cholesterol, and 3) polar lipids, which include phospholipids, glycolipids and sphingolipids. Plant leaves are coated with lipids called waxes to prevent water loss, and the honeycomb in a beehive is made of beeswax.

28. Lipids exist in either liquid or non-crystalline solids at room temperatures and are colorless, odorless, and tasteless. These are composed of fatty acids and glycerol. Structure of Lipids Are made of the elements Carbon, Hydrogen and Oxygen, but have a much lower proportion of water than other molecules such as  carbohydrates .  They are made from two molecules:  Glycerol and Fatty Acids. A glycerol molecule is made up of three carbon atoms with a hydroxyl group attached to it and hydrogen atoms occupying the remaining positions. Fatty acids consist of an acid group at one end of the molecule and a hydrocarbon chain, which is usually denoted by the letter ‘R’. They may be  saturated or unsaturated . A fatty acid is saturated if every possible bond is made with a Hydrogen atom, such that there exist no C=C bonds. Unsaturated fatty acids, on the other hand, do contain C=C bonds.

29. Classification of Lipids Classified according to their hydrolysis products and according to similarities in their molecular structures . Three major subclasses are recognized: 1. Simple lipids (a)  Fats and oils  which yield fatty acids and glycerol upon hydrolysis. (b) Waxes , which yield fatty acids and long-chain alcohols upon hydrolysis. Fats and Oils Both are called triacylglycerols because they are esters composed of three fatty acids joined to glycerol, trihydroxy alcohol. Fatty acids are the simplest form of lipids and serve as building blocks for more complex lipids. They consist of a carboxyl group attached to a long hydrocarbon chain. Waxes are esters of long-chain fatty acids with long-chain alcohols. They are highly hydrophobic and serve as protective coatings.

30. 2. Compound lipids (a) Phospholipids are a major component of cell membranes. They contain two fatty acids, a phosphate group, and a glycerol molecule. The phosphate group is hydrophilic, While the fatty acid chains are hydrophobic, making these molecules amphipathic. They may be  glycerophospholipids  or  sphingophospholipid  depending upon the alcohol group present (glycerol or sphingosine). (b) Glycolipids , which yield fatty acids, sphingosine or glycerol, and a carbo­hydrate upon hydrolysis. 3. Derived lipids: Hydrolysis product of simple and compound lipids is called derived lipids. They include fatty acid, glycerol, sphingosine and steroid derivatives. Steroid derivatives are phenanthrene structures that are quite different from lipids made up of fatty acids.

31. 35 Lipids that have at least one double bond between carbon atoms in the tail chain can accommodate at least one more hydrogen and are called unsaturated fats. Fats with more than one double bond in the tail are called polyunsaturated fats . Properties of lipids Insoluble in water Longer chains More hydrophobic, less soluble Double bonds increase solubility Melting points: Depend on chain length and saturation Double bonds lead acyl chain disorder and low melting temperatures Unsaturated fatty acids are solid at room temperature. Importance of lipids As the main component of cell membranes (phospholipids) Insulation of heat and water, Storing energy, protection and cellular communication.

32. Saturated and Unsaturated Fatty acids Saturated fatty acids are the simplest form of fats that are unbranched linear chains of CH2 groups linked together by carbon-carbon single bonds with a terminal carboxylic acid. The term ‘saturated’ is used to indicate that the maximum number of hydrogen atoms are bonded to each carbon atom in a molecule of fat. The general formula for these acids is C n H2 n +1COOH. Fatty acids obtained from an animal source are mostly even-numbered linear chains of saturated fatty acids. Saturated fatty acids usually have a higher melting point than their counterparts which is why saturated fatty acids remain in the solid-state at room temperatures. These are mostly solid and are found in animal fat like butter, meat, and whole milk. But some saturated fatty acids are also found in vegetable sources like vegetable oil, coconut oil, and peanut oil. Unsaturated fatty acids are more complex fatty acids with bent hydrocarbon chains linked together by one or more carbon-carbon double bonds with a terminal carboxylic acids group. The term ‘unsaturated’ indicates that the carbons atoms do not have the maximum possible hydrogen atoms bound to carbon atoms. Due to the presence of double bonds, the cis and trans conformation of these molecules are important. The unsaturated fatty acids found in the human body exist in the cis conformation Unsaturated fatty acids have a lower melting point as compared to saturated fatty acids, and thus they exist in the liquid state at room temperatures Most vegetable oils and fish oils are some of the important sources of unsaturated fatty acids

33. Functions of Lipids : Energy Storage : release large amounts of energy, making them an efficient form of energy storage. Structural Components : Phospholipids form the basic structure of cell membranes Insulation and Protection : In animals, fats serve as insulation to maintain body temperature and as a protective cushion around vital organs. Signaling Molecules : steroid hormones and eicosanoids, act as signaling molecules, mediating communication between cells. Vitamins and Pigments : Some lipids, such as vitamin A, D, E, and K, are vital for human health and serve various functions including vision, blood clotting, and antioxidant activity. Digestion and Absorption : Bile acids, which are derived from cholesterol, emulsify dietary fats to enable their digestion and absorption.

34. A protein is a compound made of small carbon compounds called amino acids. Proteins make up about 15 percent of your total body mass and are involved in nearly every function of your body. For example, your muscles, skin, and hair all are made of proteins. Proteins are the building blocks of life, essential for the structure, function, and regulation of the body's tissues and organs. Amino acids are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur. All amino acids share the same general structure and have a central carbon atom P roteins are made of different combinations of all 20 different amino acids. Several covalent bonds called peptide bonds join amino acids together to form proteins A peptide forms between the amino group of one amino acid and the carboxyl group of another. 38

35. 39 Structure of Proteins: Primary Structure : The sequence of amino acids in a polypeptide chain, which is determined by the DNA sequence of the gene encoding the protein. Secondary Structure : Localized folding of the polypeptide chain into structures such as alpha-helices and beta-sheets, held together by hydrogen bonds. Tertiary Structure : The overall three-dimensional shape of a protein molecule, formed by the full range of interactions among amino acid residues. Quaternary Structure : The assembly of multiple protein subunits, which can be the same or different, into a larger functional complex.

36. Functions of Proteins : Enzymes : making them proceed at a much faster rate. Structural Components : Providing support and shape to cells and forming important structures in the body like collagen in connective tissues and keratin in hair and nails. Transport : Proteins like hemoglobin transport oxygen in the blood; others transport nutrients across cell membranes. Signaling : Proteins are involved in transmitting signals within and between cells. Regulatory : Proteins regulate cellular processes by turning genes on and off or signaling other cells to do so. I mmunological : Antibodies are proteins that bind to foreign substances in the body, marking them for destruction by the immune system. Movement : Muscle contractions are driven by the proteins actin and myosin.

37. Nucleic acids: are biopolymers essential for all known forms of life. They are the molecules that store, transmit, and express genetic information in cells. There are two main types of nucleic acids: 1. Deoxyribonucleic Acid (DNA) : DNA is the carrier of genetic information. It is a double-helical molecule consisting of two long biopolymer strands coiled around each other to form a double helix. The strands are made of simpler molecules called nucleotides, each containing one of four bases (adenine [A], cytosine [C], guanine [G], and thymine [T]), a sugar molecule (deoxyribose), and a phosphate group. 2. Ribonucleic Acid (RNA): RNA is involved in various roles in coding, decoding, regulation, and expression of genes. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA, it is usually single-stranded. It also differs slightly in its chemical structure (the sugar in RNA is ribose) and uses uracil (U) in place of thymine.

38. Functions of Nucleic Acids : Storage of Genetic Information : DNA holds the instructions for an organism's or each cell's development and reproduction. Transmission of Genetic Information : DNA replicates and passes on genetic information to the offspring during reproduction. Protein Synthesis : RNA is essential in various steps of synthesizing proteins, which are crucial for the cell's structure and function. Catalytic Roles : Some RNA molecules, known as ribozymes, have catalytic properties and can carry out biochemical reactions. Structure of Nucleic Acids: Nucleotides : The basic building blocks of nucleic acids. Each nucleotide consists of a five-carbon sugar, a phosphate group, and a nitrogenous base. Backbone : The sugar and phosphate form the backbone of the nucleic acid structure, with the bases attached to the sugars. Base Pairing : In DNA, bases pair through hydrogen bonding: A pairs with T (or U in RNA), and C pairs with G.

39. 2.6 Water Water is a vital chemical substance that is essential for the survival of all known forms of life. It is a simple molecule consisting of two hydrogen atoms bonded covalently to one oxygen atom, giving it the chemical formula H2O. Physical Properties: Is a tasteless, odorless, and nearly colorless liquid, which may appear blue in large quantities. It is a polar molecule, which means that there is an uneven distribution of electron density. This gives water its ability to dissolve many other substances, earning it the nickname “the universal solvent.” Has a high specific heat capacity, which means it can absorb or release a lot of heat energy with little change in temperature. It also has a high heat of vaporization, requiring a substantial amount of energy to change from liquid to vapor.

40. Chemical Properties : Water is a solvent for a myriad of chemical substances, and it is involved in many chemical reactions. It is a medium for transporting nutrients and waste products in organisms. In liquid form, it undergoes self-ionization where one water molecule donates a proton to another water molecule to form H3O+ (hydronium) and OH− (hydroxide) ions. Water participates in the hydrolysis reactions, which is the breaking of bonds in molecules with the addition of water, such as the digestion of food. Biological Significance : Water is crucial for all cellular processes. It is involved in the metabolic reactions within cells, including respiration and photosynthesis. It acts as a temperature buffer, stabilizing the internal environment of organisms (homeostasis). primary component of the interstitial fluid and is used for transportation of substances in biological systems. It serves as a lubricant and cushion for joints, the spinal cord, and in the amniotic sac surrounding fetuses in the womb.

41. Water cycles through the environment via the hydrologic cycle, which includes evaporation, condensation, precipitation, and runoff It is an essential component of all ecosystems and is necessary for all forms of life, from the simplest microbial life forms to complex organisms. Distribution on Earth : About 71% of the Earth’s surface is covered by water, mostly in oceans and large bodies of water. However, less than 3% of the world’s water is freshwater, the majority of which is trapped in glaciers and polar ice caps. The availability of clean, fresh water is essential for human health and civilization. Challenges : Despite its abundance, access to clean and safe drinking water is a problem in many parts of the world due to pollution, overuse, and distribution challenges. Water scarcity is becoming a more pressing issue with climate change, as patterns of water circulation change, affecting agriculture and food security.

42. 46 2.5. Vitamins Vitamins are organic compounds that are needed in small amounts for metabolic activities. Many vitamins help enzymes function well. Vitamin D is made by cells in your skin. Some B vitamins and vitamin K are produced by bacteria living in the large intestine. Sufficient quantities of most vitamins cannot be made by the body, but a well- balanced diet can provide the vitamins that are needed. Some vitamins that are fat-soluble can be stored in small quantities in the liver and fatty tissues of the body. Other vitamins are water- soluble and cannot be stored in the body. Foods providing an adequate level of these vitamins should be included in a person‟s diet on a regular basis.

43. There are 13 essential vitamins, each of which has a specific role in the body, and they are divided into two categories: water-soluble and fat-soluble . Water-soluble vitamins : Vitamin C (Ascorbic Acid): Important for the synthesis of collagen, the absorption of iron, and the maintenance of immune system health. B Vitamins : Essential for glucose metabolism and normal nerve, muscle, and heart function. Plays a key role in energy metabolism and supports cellular function, growth, and development. Helps convert food into energy by aiding enzymes and is important for the nervous system, digestive system, and skin health. Necessary for the synthesis of coenzyme A (CoA), hormone production, and fat metabolism. Involved in amino acid metabolism, red blood cell production, and the creation of neurotransmitters. Needed for carbohydrate, fat, and protein metabolism as well as healthy hair, skin, and nails. Required for proper brain function and plays an important role in mental and emotional health. Necessary for the production of red blood cells and the maintenance of the central nervous system.

44. Fat-soluble vitamins : Vitamin A (Retinol) : Vital for healthy vision, skin health, and immune function. Vitamin D: Essential for the regulation of calcium and phosphorus, and in maintaining proper bone structure. Vitamin E (Tocopherol): Acts as an antioxidant, helping to protect cells from the damage caused by free radicals. Vitamin K: Important for blood coagulation and regulating blood calcium levels. Functions of Vitamins : They act as catalysts in enzymes reactions, with small amounts of vitamins necessary to turn proteins, carbohydrates, and fats into energy. Some vitamins (e.g., A, D, E, K) are also important for vision, bone growth, cell function, and cell protection. They support the immune system, brain function, and the nervous system. Vitamins help in the production of DNA, hormones, and other critical substances. Sources: Fruits, vegetables, grains, dairy products, and meats are all significant dietary sources of vitamins .

45. 49 Activity (Think Scientifically) 2.7. Minerals are inorganic compounds used by the body as building material, and they are involved with metabolic functions. For example, the mineral iron is needed to make hemoglobin and it binds to hemoglobin in red blood cells and is delivered to body cells as blood circulates in the body. Calcium, and other minerals, is an important component of bones and is involved with muscle and nerve functions and they serve as cofactors for enzymes . Magnesium is an important component of the green pigment, chlorophyll , involved in photosynthesis.