SHS Physical Science Biological Macromolecules PDF

SHS Physical Science Biological Macromolecules  Target Your basic nutritional needs as humans are the macromolecules you have heard since you were in Grade 1. These are carbohydrates, lipids, nucleic acid, and proteins. Though many times you...

SHS Physical Science Biological Macromolecules  Target Your basic nutritional needs as humans are the macromolecules you have heard since you were in Grade 1. These are carbohydrates, lipids, nucleic acid, and proteins. Though many times you have heard about them, lessons about food never run out of fashion, so to speak, because food is something we need every day. Time and again, you need to learn more about the nutrients you take in because young people this to be successful in life. While food culture evolves due to technology and commercialism, the basic nutrients one needs every day remain the same. And in case you have any problem with your personal health, the food you eat is one aspect you can program and control to address some of these problems. This module will provide you with information and activities to help you understand better the structures, properties and functions of macromolecules such as carbohydrates, lipids, nucleic acid and proteins. After going through this module, you are expected to explain how the structures of biological macromolecules such as carbohydrates, lipids, nucleic acid and proteins determine their properties and functions (S11/12PS-111e-22). Learning Objectives: 1. identify the four biological macromolecules 2. describe the structures of carbohydrates, proteins, nucleic acids and lipids from one another 3. distinguish the properties and functions of the biological macromolecules 4. relate the broad functions of the macromolecules to their complex structures 1 LU_Physical Science_Module4  Pre-test Direction: Read each item carefully. Write the letter of the correct answer. 1. What is the form of carbohydrates that body cells readily absorb? A. Fructose B. Galactose C. Glucose D. Sucrose 2. How many sugar units does a disaccharide have? A. 1 B. 2 C. 3 D. 4 3. What form of carbohydrates is the most common? A. Fructose B. Galactose C. Glucose D. Sucrose 4. Which of the following is a source of protein? A. Avocado B. Citrus C. Pizza D. Chicken 5. If we drink plenty of water, what nutrients would be supplied to our bodies? A. Carbohydrates B. Fat C. Protein D. None 6. Which of the following would be a good source of carbohydrates? A. Cassava B. Crab C. Egg D. Eggplant 7. Which of the following elements is present in carbohydrates? A. Beryllium B. Carbon C. Chlorine D. Copper For numbers 8-10, refer to the following choices: A. Cell growth and repair B. Provides immediate energy C. Stores genetic material D. Structure of cell membrane 8. What is one function of proteins? 9. What is one function of fats/lipids? 10. Which is a function of nucleic acids? 11. Protein has many forms. Which of the following is NOT? A. Cholesterol B. Enzyme C. Hemoglobin D. Insulin 12. Which is NOT a structure of DNA? A. Sugar B. Phosphate group C. Steroid D. Nitrogenous base 13. Which pair contains saturated fats that are generally solid at room temperature? A. Butter and cheese B. Butter and margarine 2 LU_Physical Science_Module4  C. Canola and corn oil D. Cheese and corn oil 14. Which nutrient is a double helix structure? A. Carbohydrates B. Fat C. Protein D. Nucleic Acid 15. What is the function of DNA? A. Cell growth and repair B. Provide energy C. Stores genetic material D. Provides insulation Jumpstart Activity 1: You Are What You Eat! Direction: Think of a previous full meal that you enjoyed very much! List down the names of the food prepared for that meal. Then try to classify them as to carbohydrates, proteins, nucleic acids and lipids. Here you can also analyze if that meal was balanced or not, healthly or not. Name of Food Classification (Carbohydrates, proteins, nucleic acid, lipids) 1 2 3 4 5 Activity 2: “Memory Lane” Direction: In this exercise, you will be tested on your previous knowledge in Biology by completing the following table with the basic information about the Biological Macromolecules. Macromolecule Monomer Function Monosaccharide 1. 6. Energy storage, 2. 4. membranes and steroids Proteins 5. 7 3. Nucleotides 8. 3 LU_Physical Science_Module4  Discover Carbohydrates A carbohydrate comprises the bulk of a typical meal because it is an energy source. It is said to be the most abundant molecule on earth made up of three most common elements in nature – C, H and O. They are used by all living things. With an empirical formula, (CH₂O)n, carbohydrates are classified into three: monosaccharides, disaccharides and polysaccharides. Examples of carbohydrates are glucose, sucrose, starch, cellulose, and chitin. Let us look at the chemical structure of each classification. Monosaccharides (‘sacchar’ means sweet). This is carbohydrates with about three to seven carbon atoms. The most common carbohydrate is glucose. It is a monosaccharide because it has one carbon chain or carbon ring. In humans, glucose is the simplest molecule that could be absorbed by the cells. It is sweet, colorless, solid at room temperature and extremely soluble in water. Examples of monosaccharides are glucose, fructose, erythrulose and ribulose. Figure 1. Structure of Glucose Source: https://www.visionlearning.com Disaccharides. As the name implies, this carbohydrate is made up of two rings of carbon resulting from the combination of monosaccharides in a process known as dehydration synthesis. The process is dehydration because a molecule of water is removed and synthesis because two monosaccharides are put together. Examples are sucrose, lactose, and maltose. 4 LU_Physical Science_Module4  Figure 2. Structure of Sucrose Source: https://www.visionlearning.com Polysaccharides contain more than ten (10) monosaccharide units and can be a hundred of sugar units. The chain maybe branched or unbranched. There are two (2) distinct types: starch and non-starch. 1. Starch polysaccharides. These are the main energy reserve in root vegetables such as onions, carrots, potatoes, and whole grains. Some starches can only be digested by the gut microbiota rather than our own body’s mechanisms: these are known as resistant starches like those found in beans, peas, lentils, green bananas, whole grains like oat & barley, cooked and cooled rice. The corresponding polysaccharide in animals is glycogen. 2. Non-starch polysaccharides. These are the dietary fiber group. They are found in vegetables, fruits, whole grains in the form of cellulose, hemicellulose, pectin and gums. As fiber, humans cannot digest them so that their average energy content compared to most carbohydrates is lower. However, some types of fiber can be metabolized by gut bacteria producing compounds that are good for our body. Figure 3. Structure of Starch Source: https://www.sciencedirect.com Functions of Carbohydrates 1. Energy supply. When broken down into glucose, they provide energy directly to cells in the body such as the muscles, brain, heart, and kidneys, enabling the body to perform its functions. Without energy, none of the other life processes are performed. The indigestible portions of carbohydrates referred to as dietary fiber, increase the physical bulk of the bowel for easy movement through the colon out of the body. 2. Energy storage. Excess glucose is stored. In the human body in the form of glycogen in the muscles, and in the liver, while in plants, it is stored as starch. In times when the body uses up the glucose supply after excessive physical activity or prolonged hunger, this stored energy in the form of fat is converted back to glucose. Therefore, glucose supply will prevent the degradation of skeletal muscle and other tissues such as the heart, liver, and kidneys. 5 LU_Physical Science_Module4  3. Building macromolecules. Some glucose is converted to ribose and deoxyribose, which are forms of sugar used as the building blocks of RNA, DNA, and ATP. Proteins Protein is said to be the growth nutrient. The building blocks are the 20 different amino acids commonly found in plants and animals. Any protein is made up of about 300 or more amino acids sequenced in a unique manner providing a specific shape that will determine its specific function. Every species, including humans, has its own characteristic proteins. In other words, the amino acids are common in all living things, but because of the varying needs of each organism, the sequencing or arrangement of amino acids varies from organism to organism to come up with the protein required to meet a specific need at any given time. For instance, proteins produced during periods of rapid growth or increased demand, such as childhood, and adolescence may not be the hormones produced during pregnancy and breastfeeding. Amino acids are classified as either essential or non-essential. Essential amino acids cannot be produced by the body and therefore must come from the diet. Nine of the 20 amino acids are essential. They are phenylalanine, lysine, valine, tryptophan, histidine, methionine, leucine, isoleucine and threonine. On the other hand, non-essential amino acids can be produced by the body and, therefore, do not need to come from the diet. Figure 4. Basic Structure of Figure 5. Basic Structure of Amino Acid Amino Acid Lysine Source: https://www.visionlearning.com Source: dreamstime.com Each amino acid has a side chain. It is this side chain that makes each amino acid different, giving it a unique set of chemical properties that further define its function. Functions of Proteins Since a protein is a result of a particular arrangement of certain amino acids, it follows that each protein has particular properties and functions. Let us learn about the different proteins. 1. Antibodies. These are proteins found in the blood made by white blood cells called B cells. They help recognize and destroy foreign pathogens in the immune system, thus, fight infections. 6 LU_Physical Science_Module4  2. Enzymes. These proteins speed up chemical reactions such as blood clotting to DNA synthesis to digestion such that reactions that would take years could happen only in seconds. They do this either by breaking down molecules into smaller pieces or by building up large molecules without themselves being and without affecting the reactants and products in the reactions they catalyze. There are approximately 1300 different enzymes found in the human cell. 3. Hormones. These are proteins used by the cell in receiving and sending chemical signals, thereby coordinating bodily functions. For example, insulin controls our blood sugar concentration by regulating the uptake of glucose into cells. Hormones include insulin, estrogen, testosterone, adrenaline, cortisol etc. Figure 6. Structure of Insulin Source: slideshare.net 4. Transport. These proteins move molecules across cell membranes. For example, hemoglobin in the blood helps transport oxygen to the different parts of the body. 5. Contractile function. These are involved in muscle contraction enabling movement such as walking, writing, and chewing. Examples are actin and myosin. 6. Support Structure. These provide support to organisms. For instance, the proteins in our bones provide framework to the human body. Protein fingernails and hair such as collagen and elastin provide support to humans. 7. DNA synthesis and repair. These are proteins associated with regulating chromosome structure during cell division and in regulating gene expression. Examples are histones and cohesin. Lipids Lipids, usually called fats, are a family of organic compounds mostly insoluble in water. They are also said to yield high energy. Fatty acids are the building blocks of the lipids (fats). They are produced when digestion breaks down fats. Fatty acid is the basic structure of fat, which can then be absorbed into the blood. In this discussion when we use the word fat, we are referring to lipids. 7 LU_Physical Science_Module4  Fatty acids may be saturated or unsaturated. Saturated fats are fatty acids where the four arms of carbon are all bonded to hydrogen. The C-H bond is stronger bond compared to C-C bond. This is the reason why saturated fat in butter, cheese and red meat are solid at room temperature. These are also said to be less healthy than unsaturated fats because they increase the levels of lowdensity lipoprotein, also known as ‘bad’ cholesterol, that may increase the risk of cardiovascular disease. Unsaturated fat, on the other hand, is composed of fatty acids with two carbon atoms connected by a double bond, which is considered a weak bond compared to a purely C-H bond. This is why unsaturated fats, such as vegetable oil (sunflower, corn, canola) are liquid at room temperature. They are also said to be more healthy. They include avocados and avocado oil, olives and olive oil, peanut butter and peanut oil, fatty fish, such as salmon and mackerel, nuts and seeds, such as almonds, peanuts, cashews, and sesame seeds Figure 7. Structure of Saturated and Unsaturated Fats Source: https://wordpress.com Let us take a look at the three main types of lipids. 1. Triacylglycerols (also known as triglycerides). These make up more than 95% of lipids in the diet of fried foods, butter, whole milk, cheese, and some meats. The terms fats, oils, and triacylglycerols are usually interchangeable unless specified. Triglycerides are made of fatty acid molecules joined together in groups of three. They are also made in our bodies from the carbohydrates that we eat. 2. Phospholipids. These are lipids whose fatty acid component has been replaced by a phosphate group (PO₄). As a major component of the cell membrane, it is a bilayer whose “head” or upper layer is hydrophilic, meaning it dissolves readily in water. It is an example of polar. On the other hand, its “tail” or lower layer is hydrophobic, or it does not dissolve in water. It is non-polar. Because of this property, phospholipids are an effective barrier to the passage of ions and molecules into and out of the cell. This means that practically all molecules in a water solution can enter the cell. But because of the hydrophobic layer, not all of these molecules can enter the cell. 3. Sterols. These lipids appear as tetrameric (4-sided) rings comprising about 50% of the membrane lipid content in cells, thus altering the membrane fluidity and structure. The most common sterol in the animal membrane is cholesterol, which is about 20% of all sterols present in organisms. Cholesterol is manufactured by the human body, so there is a need cholesterol-rich food (such as animal fats, sausages, and butter) in moderation. Ergosterol are 8 LU_Physical Science_Module4  found in membranes of fungi and protists, while phytosterols are found in plants. Functions of Lipids There are three primary biological functions of lipids within the body. 1. Structural components of cell membranes. Phospholipids are the major component of cell membrane structure. 2. Energy storehouses. When one eats a lot of carbohydrates, the excess glucose is stored as glycogen by the liver, and then this is converted back to glucose by the liver as the need arises. For instance, when one has done heavy work like cleaning the house, working in the fields, or playing basketball. These activities have exhausted all the glucose derived from a certain meal, that the liver converts the glycogen back to glucose. 3. Important signaling molecules. The lipids in the cell membrane receive the signal from outside the cell. A chemical signal which is a “primary messenger” that cannot get inside the cell and so binds to receptor on the membrane activating enzymes. These enzymes cleave the surface of lipid to transmit the message making the lipids the “secondary messenger” that can bind with intracellular enzymes. This activates intracellular processes to respond to the message. Likewise, lipids in plant membranes can sense extracellular conditions such as temperature, salinity, and pathogen attack. It can also serve as stress mitigators in plants. Nucleic acid This is a macromolecule made out of basic units called nucleotides. A nucleotide consists of a sugar attached to a phosphate group and any of the nitrogen- containing bases cytosine, guanine, adenine, and thymine. The nucleic acids are found in all living organisms, from tiny bacteria to multicellular organisms like us. There are two varieties of nucleic acid. 1. Deoxyribose nucleic acid (DNA). This is a double helix molecule composed of a sugar deoxyribose, a phosphate and a nitrogen-containing bases cytosine, guanine, adenine, and thymine. It is found in the nucleus of the cell. 2. Ribose nucleic acid (RNA). This single strand molecule whose sugar is ribose. It is found in the nucleolus. It also uses the same nucleotides as the DNA for thymine because it is replaced by uracil in RNA. It is found in the cytoplasm of the cell. Functions of Nucleic Acids 1. Storage and expression of genetic information. Deoxyribonucleic acid (DNA) encodes the information the cell needs. The sequence of the molecule encoded can give a message, “make this protein, and replicate me”. The cell supplies the nucleotides needed for the manufacture of that specific protein. The resulting 9 LU_Physical Science_Module4  protein would help in the expression of a certain trait such as color of hair or height. 2. Protein Synthesis. RNA, on the other hand, participates in the actual making of protein, known as protein synthesis. It converts stored information in DNA to make proteins. It is also used by viruses as genetic material. Deoxyribose nucleic acid (DNA) Ribose nucleic acid (RNA) Figure 9. Structure of Nucleic Acids Explore Enrichment Activity 1: Table Completion Direction: To summarize the concepts you have learned in this lesson, you are going to complete the following table. Several clues are already given. Macromolecule Basic Examples (2) Main Functions(2) Component 1. Myosin 1. Amino acid 2. 2. 1. 1. Fatty acid 2. 2. 1. 1. Nucleic acid 2. 2. 1.Glycogen 1. 2. 2. 10 LU_Physical Science_Module4  Enrichment Activity 2: “Two-Day Meal Plan” Direction: Think of a 2 – day healthy meal plan for a teenager like yourself and write it in the table below. Make sure that you choose the right kind of food containing carbohydrates, proteins, and lipids. Day 1 Day 2 Breakfast Morning Morning Snack Lunch Afternoon Snack Dinner Dessert Deepen Performance Task: My Health Reflection Direction: Read the following selection, afterward write a 50-word reflection on the importance of the hormone insulin to humans, and mention the things you can do as a student to avoid becoming diabetic. Please take note of the rubric below. According to DOH Secretary Francisco Duque III, “Diabetes keeps on increasing in prevalence, but we shouldn’t give up the fight against the disease. It maybe chronic and incurable, but diabetes can be managed. We need to strengthen multi-stakeholder collaboration in increasing awareness of this disease, and for people to follow a healthy lifestyle. Diabetes is a familial (meaning it runs in the family or it is hereditary) as well as a lifestyle disease. By exercising, eating healthy, and avoiding sugary drinks, we can prevent diabetes. For the 4 million Filipinos who are already affected by diabetes, it is not just to do this but also to see their doctor regularly and ensure that they stay on medications to avoid complications such as kidney failure and cardiovascular disease. It destroys many of the organs of the body. It’s the no. 1 cause of blindness, the no 1 cause of kidney failure that leads to dialysis and transplants. It destroys or blocks the blood vessels in the heart, in the brain, and in the legs, so that the risk getting a heart attack or stroke is higher.” (Source: https:// www.doh.gov.ph Nov 14, 2017) 11 LU_Physical Science_Module4  The Three Types of Diabetes Type 1 (Juvenile diabetes). This is characterized by the failure of the pancreas to produce enough insulin causing a high level of sugar in the blood; Type 2 (Adult diabetes). This starts with insulin resistance, or when cells fail to respond to insulin properly, soon lack of insulin may also develop; Type 3 (Gestational diabetes). This occurs when a pregnant woman without a history of diabetes develops high blood sugar levels. Common symptoms are frequent urinating, thirstiness, hunger, extreme fatigue, blurry vision, slow healing of cut/bruises, weight loss even when eating more (type1), tingling, pain or numbness in the hand (type 2). (Source: Pacholo Concepcion (lifestyle.inquirer.net) Rubrics for a 50-word Reflection CRITERIA Exceed Meet Almost meet Below expectations 5 expectations 4 expectations 3 expectations 2 Number of Words 40-55 words 30-39 words 20-29 words 10 words or less Content (Mention Expression of Expression of Action is not None of things to do to personal action of specified included avoid becoming action other people diabetic) Content Clearly Fairly Barely Does not (Importance of explains explains explains explain the Insulin) importance of importance importance of importance the hormone of the the of insulin. insulin hormone hormone insulin insulin Grammar & Reflection Reflection Reflection Reflection Conventions contains 5 or contains contains 11- contains less errors. 610 errors. 20 errors. more than 20 errors. 12 LU_Physical Science_Module4  Gauge Direction: Read each item carefully. Write the letter of the correct answer. 1. What is the main source of energy for organisms? A. Fructose B. Galactose C. Glucose D. Sucrose 2. Proteins are made of building blocks. Which one is it? A. Amino acid B. Ammonia C. Carbohydrate D. Polypeptide 3. Which of the following is NOT a subunit of a nucleotide? A. Glycerol C. Phosphate B. Nitrogenous base D. Sugar 4. Which macromolecule do Glycogen, Starch and Cellulose belong? A. Carbohydrates B. Lipids C. Nucleic Acids D. Proteins 5. When disaccharides are broken into monosaccharides, what is the process involved? A. Activation B. Dehydration C. Digestion D. Hydrolysis 6. Which of the following is NOT made up of proteins? A. Cellulose B. Enzymes C. Fingernails D. Hair 7. What do saturated fats have that distinguish them from unsaturated fats? A. They have doubles bonds. B. They have no double bonds. C. They have electrostatic charges. D. They are associated with heart disease. 8. Which of the following is NOT related to protein? A. DNA encoding B. Muscle composition C. Speeding up of chemical reactions D. Formation of cell membrane bilayer 9. Which of the following tasks is NOT a job of proteins? A. Cell Growth B. Receive and send signal C. Store genetic information D. Speed up chemical reaction 10. Which macromolecule stores energy, insulates us, and make up the cell membrane? 13 LU_Physical Science_Module4  A. Carbohydrates B. Lipids C. Nucleic Acids D. Proteins 11. During photosynthesis, plants capture light energy from the sun to make glucose. When plants produce a lot of glucose during summer, these are stored in the plant. In what form is excess/unused glucose stored in plants? A. Cellulose B. Chitin C. Glycogen D. Sucrose 12. Which of the following pairs has components that are UNRELATED? A. Fat and lipid B. Sugar and carbohydrate C. Amino acid and protein D. Glycogen and nucleic acid 13. Which of the following explains why sterols (or steroids) are considered to be lipids? A. They are water soluble. B. They are rich in hydrogen. C. They contain fatty acids. D. They are used as storage fats. 14. Cholesterol is a lipid. Why is it NOT advisable that we eat a lot of this in the diet? A. Cholesterol is healthy. B. Excess fats regulate body weight. C. Good cholesterol increases risk of heart disease. D. What the body needs is naturally produced by the body. 15. You helped fix your backyard garden, and a big unstable rock fell on one foot! Frightened, you were able to remove the rock quickly by yourself because your muscles store energy for this kind of emergencies. What macromolecule is this? A. Carbohydrates B. Lipids C. Nucleic Acids D. Proteins 14 LU_Physical Science_Module4