Biological Molecules PDF

LESSON 6.1: BIOLOGICAL MOLECULES - The removal that takes place is equivalent to removing a water Also known as biomolecules, are large molecule, hence the name molecules necessary for life that are bu...

LESSON 6.1: BIOLOGICAL MOLECULES - The removal that takes place is equivalent to removing a water Also known as biomolecules, are large molecule, hence the name molecules necessary for life that are built dehydration reaction/condensation. from smaller organic molecules. Hydrolysis Reaction Biological Macromolecules A molecule of water is added instead of Biological macromolecules are organic removed. which means that they contain carbon. - A hydrogen atom is attached to one The four biological macromolecules are: subunit and a hydroxyl group to the carbohydrates, proteins, lipids, proteins, other, which breaks a specific and nucleic acids. covalent bond in the macromolecule. - These four form polymers with the monomers that make them. - They can be found not only on food LESSON 6.2: CARBOHYDRATES products but also in cellular context. Carbohydrates are a loosely defined group Monomers and Polymers of molecules that all contain carbon, hydrogen, and oxygen in the molar ratio Molecules can join together to form large 1:2:1. structures called macromolecules. Carbohydrates, with their many - Monomers are small molecular carbon–hydrogen (C—H) bonds that subunits that make up biological release energy upon oxidation, are ideal for macromolecules energy storage. Sugars are especially - Polymers are long chains of important for this role. monomers that build up the biological macromolecules. - For animals, carbohydrates are a primary source of dietary energy Making and Breaking Biological while for plants, it serves as a Macromolecules building material for the plant body. Polymers are built via chemical reactions Carbohydrates are classified into three: termed dehydration reactions and are broken down by hydrolysis reactions. - Monosaccharides (simple sugar) - Disaccharides (complex sugar) Dehydration Reaction - Polysaccharides (more complex) - Linking of two monomers involves the removal of an -OH group from Monosaccharides one monomer and the removal of a - The simplest type of carbohydrate. Hydrogen (H) atom from the other. - Contain as few as three carbon atoms.  - They are the building blocks for - They are made by linking two more complex sugars and are small monosaccharides. Additionally, they molecules that cannot be further serve as transport molecules in digested. plants and provide nutrition in - Highly soluble and can pass through animals cell membranes easily. - In plants and many other organisms, glucose is converted into a transport Isomers - Organic compounds with the form before it is moved from place to same molecular formula but different place. structures. Maltose (glucose + glucose) - Isomers are like words that contain - Made up of two subunits of glucose the same letters in a different order found in malt and saliva. (earth and heart) - Major breakdown product of starch. - It is naturally found in germinating Glucose (grape sugar/dextrose sugar) seeds. - It is the most common monosaccharide, and is also a Sucrose (glucose + fructose) product of photosynthesis together - Its form is what most plants use to with oxygen. transport glucose. Additionally, it is - Has two isomers: ɑ-glucose and the sugar that most humans and β-glucose other animals eat. - It is an important energy source in - Sugarcane and sugar beets are rich both animals and plants. in sucrose. - It is a major free sugar circulating with the blood in higher form of Lactose (glucose + galactose) animals. - Serves as a supply of energy for offspring in mammals. Fructose (fruit sugar/corn sugar) - Adults often have greatly reduced - Often bonded to glucose to form the levels of lactase, which results in disaccharide sucrose. lactose intolerance. - Occurs in fruits, sugar canes, syrups, and certain vegetables Polysaccharides Galactose (mammalian sugar) Polysaccharides are long polymers made - Bonded to glucose to form lactose up of monosaccharides that occur through (milk sugar). dehydration reactions. - Found in complex carbohydrates and in carbohydrates containing - They are insoluble in water lipids (glycolipids), which occur in - They cannot diffuse through cell the brain and other nervous tissues membranes because they are large of most animals. molecules. Disaccharides Starch  - Storage form of carbohydrates in - They are the building blocks for plants. forming nucleic acids, such as DNA. - The excess glucose is stored as - They synthesize lubricants, such as starch in different plant parts, mucus, which consists of carbohydrates and including seeds and roots. proteins. - It is found in storage organs of plants like potato tubers and tapioca. - They synthesize nectar in some flowers (nectar is a sweet liquid that plants Cellulose produce to attract insects) - It provides structural support in the cell wall of plants. LESSON 6.3: LIPIDS - Humans lack cellulase — the enzyme that functions to dissolve Lipids are fatty, oily, or waxy organic cellulose. compounds. They vary in structure, but are all hydrophobic. Glycogen - Storage form of carbohydrates in - They are the main structural mammals. component of all cell membranes. - A branched molecule made up of Cells use them to make other many glucose molecules joined compounds, to store energy, and as together. waterproofing or lubricating - It is digested to glucose to provide substances. energy for cell activities. This is stored in the liver and muscles of Many lipids are built from a simple skeleton mammals. made up of two kinds of molecules: Roles of Carbohydrates: 1.) Fatty acids - long-chain hydrocarbons; hydrophobic tails. - Monosaccharides and disaccharides are good sources of energy in living 2.) Carboxyl group - carboxylic acid organisms. They can be used in respiration, (COOH) at one end; hydrophilic head. in which their energy is used to make ATP. - Glucose is transported and Structures of Fatty Acids dissolved in blood plasma. In plants, 1.) Saturated - have only single bonds sucrose is transported in phloem sap. linking in their tails. They contain as many hydrogens as they can hold. - They serve as a substrate for respiration to provide energy for cell - Solid at room temperature and are activities. mostly found in animals (fats). - Too much of this could lead to - They form supporting structures, coronary heart disease. such as cell walls in plants. 2.) Unsaturated - have double bonds, - They will be converted into other reducing the number of bonded organic compounds, such as amino acids hydrogen atoms and fats.  - Liquid at room temperature (e.g. Waxes olive oil) and are mostly found in plants (oils) Waxes are mostly found in surfaces of - May be converted into trans fat. plants and skin of animals and humans. Types of Lipids They are solid at normal temperatures because they have a high melting point. Additionally, they are hydrophobic which Triglyceride makes them resistant to degradation. A type of fat made up of a glycerol molecule bonded to three fatty acids. Roles of Lipids: Glycerol has three carbon atoms, each with an -OH group (hydroxyl group). When the - Serves as long-term storage of three fatty acids attach to these three -OH energy. groups, they form a triglyceride. - They are used for making biological membranes. - Hydrocarbon chains of fatty acids - For insulation. vary in length. The most common - Protection (e.g. preventing leaves are even-numbered chains of 14 to from drying up.) 20 carbons. - Cell buoyancy. Phospholipids - Acts as hormones. Are basically triglycerides, but a polar LESSON 6.4: PROTEINS phosphate group is attached to glycerol. Proteins are linear polymers constructed This setup creates a polar "head" (the from amino acid monomers. They are made phosphate) and nonpolar "tails" (the two with 22 different amino acids, and are the fatty acids), which helps phospholipids form most diverse molecules of life. cell membranes by arranging themselves into layers with heads facing water and tails A protein is a folded polypeptide with a tucked inside. specific function; some proteins contain multiple polypeptide chains, allowing for a Steroids large number of amino acids. - Steroid molecules have skeletons of An amino acid is composed of: four fused carbon rings. 1. Functional amine group - NH₂ - Cholesterol provides physical 2. Carboxyl/Acid group - COOH stability to an animal cell’s plasma 3. The variable - R group which makes membrane. amino acids differ from one another. - It is also the precursor of sex hormones testosterone and Peptide bond - the covalent bond that links estrogen. amino acids in a protein. Polypeptide - a chain of many amino acids - DNA is stored in the cell as long joined by peptide bonds. fibers called chromosomes - DNA’s structure is a double helix. Major Types of Proteins: Ribonucleic Acid (RNA) 1. Structural Proteins - provide support. (e.g. toughness of hair and - Contains the sugar ribose. horns.) - Has a distinct base called uracil. 2. Storage Proteins - provide amino - Contains a polynucleotide chain that acids for growth. (e.g. seeds and is identical to a DNA polynucleotide eggs) chain. 3. Contractile Proteins - help - RNA’s structure is single-stranded. movement. (e.g. contraction of muscles. Nucleotides 4. Transport Proteins - help transport substances (e.g. transport of oxygen - are building blocks of nucleic acids; in red blood cells) some have additional roles in 5. Enzymes - help chemical reactions. metabolism. (e.g. digestion of food) Three Parts of a Nucleotide Roles of Proteins - Synthesis of new protoplasm Center - five carbon sugars; deoxyribose for - For growth and repair of worn-out DNA and ribose for RNA. body cells - Synthesis of enzymes and some Attached to the sugar (I) - hormones. negatively-charged phosphate group. - Formation of antibodies. Attached to the sugar (II) - nitrogenous base LESSON 6.5: NUCLEIC ACIDS made of one or two rings. It is called base because it accepts hydrogen ions in Nucleic acids are macromolecules that aqueous solution. provide the directions for building proteins. Its name comes from their location in the Sugar and phosphate are the same nuclei of eukaryotic cells. in all nucleotides; only the base varies. Nucleic Acid has two types which are deoxyribonucleic acid (DNA) and DNA RNA Ribonucleic acid (RNA) Adenine A Uracil U Deoxyribonucleic Acid (DNA) - Genetic material that humans pass Thymine T Adenine A on to their offspring. Guanine G Cytosine C - Has thymine Cytosine C Guanine G