Macromolecules Unit 1 Lesson 7

Students will be able to: Macromolecules Students will be able to: Classify the variety of macromolecules. Describe how polymers are formed and broken down in organisms. Compare the chemical structures of carbohydrates, lipids, proteins, and nucleic acids, and relate their importance to living organisms. Key Vocabulary: Macromolecule, monomer, polymer, condensation reaction, carbohydrates, monosaccharides, disaccharides, polysaccharides, lipids, fatty acids, proteins, enzymes, hormones, nucleic acids, DNA, RNA.

Macromolecules Do you have ever read a nutrition facts ticket on the back of your lunch items? If so, you might have a look at the carbohydrates, protein and lipids or fat content. Now, you may be identified different macromolecules we will discuss in this lesson. These large biomolecules providing you with a building block that make and maintain your body.

Macromolecules The Carbon role in life The carbon tends to form four covalent bonds to fill the outer energy level. The carbon atom usually has an ability to bond with other carbon atoms, as well as bonding with other elements. When two carbon atoms form a covalent bond, each atom could form single bond, double bond or triple bond.

Macromolecules The Carbon role in life The carbon atoms bond to each other in many ways to form various compounds such as, straight chains, branched chains, or rings. Actually, these compounds can have any number of carbon atoms and may contain atoms of many other elements, so a huge number of carbon compounds can be synthesized in our body.

Macromolecules Monomers and Polymers Cells synthesize biomolecules by bonding small molecules together. These large biomolecules are called polymers that can be defined as long chain of repeating subunits or small molecules that called monomers such as amino acids that made up protein.

Condensation reaction (dehydration synthesis) Macromolecules Condensation reaction (dehydration synthesis) Polymers are synthesized by a condensation chemical reaction. In this reaction, the monomers that are attached together to make the biomolecule have a hydrogen atom (–H) and a hydroxyl group (–OH) group that are removed to release water. These subunits become bonded by a covalent bond. These polymers can be broken apart by hydrolysis.

Macromolecules Carbohydrates One of the most abundant macromolecules in the living cell are the carbohydrates and considered as the fuel source for living cells. The carbohydrate is defined as the biomolecule that contains carbon, hydrogen, oxygen atoms. The ratio of these atoms is approximately two hydrogen atoms and one oxygen atom per one carbon atom.

Macromolecules Carbohydrates Carbohydrate molecules have various chain lengths. There are three categories of biologically important carbohydrates: Monosaccharides Disaccharides Polysaccharides

Macromolecules Monosaccharides Monosaccharides (mono- = “one”; sacchar- = “sugar”) are the simplest type of carbohydrates and typically contains from 3 to 7 carbon atoms. The most common examples of this category are the isomers glucose and fructose.

Macromolecules Disaccharides Disaccharides (di- = “two”) is a two-sugar molecule that formed when two monosaccharides join via a condensation reaction or dehydration synthesis. For example, when glucose and fructose link together by a dehydration synthesis, a molecule of sucrose which is known as table sugar, is produced.

Macromolecules Polysaccharides Polysaccharide (poly- = “many”) is the largest carbohydrate molecule and defined as long chain of monosaccharides linked by covalent bonds. These biomolecules usually have a high molecular weight. Starch, glycogen, cellulose, and chitin are examples of polysaccharides that is very important in living organisms.

Macromolecules Polysaccharides Starch molecule consists of branched chains of glucose molecules and is utilized as energy storage by plants. Glycogen is a highly branched glucose polymer that function as energy store in the mammal's liver. Cellulose is another glucose polymer that typically found in the plant cell walls and serve as structural support.

Macromolecules Lipids Lipids are the second group of large biomolecules that are typically consists of carbon and hydrogen associated with a small amount of oxygen atoms. lipids are used to store energy, serve as insulation, forming cell membranes, and provide building blocks for hormones like testosterone. Fats, oils, waxes, and steroids are the most common examples of lipids.

Macromolecules Lipids The lipid molecules are made of glycerol which is a three carbons molecule that serves as a backbone in which the fatty acids attached to form a lipid molecule. A fatty acid is a long chain of carbon and hydrogen. There are three kinds of fatty acids: saturated, unsaturated, polyunsaturated fatty acids.

Macromolecules Proteins Proteins is one of the most abundant macromolecules and a single living cell contains thousands of proteins that perform unique functions such as contraction of muscle tissue, transportation of oxygen in the bloodstream, providing immunity, regulating other proteins, and carrying out chemical reactions.

Macromolecules Proteins Amino acids are monomers that form building blocks of protein molecule. There are about 20 natural occurring amino acids that in various combinations, produce thousands of proteins. The typical amino acid is composed of a central carbon atom to which are attached a hydrogen atom, carboxyl group (–COOH), an amino group (–NH2), and a variable group (–R) that makes each amino acid different.

Macromolecules Proteins Amino acids are bounded together by a covalent bond that called a peptide bond. The peptide bond is formed when an –H atom from the amino group of one amino acid and an –OH group from the carboxyl group of another amino acid are removed to release a water molecule.

Macromolecules Proteins Precisely, a protein molecule is made up of one or more linear chains of amino acids that is called a polypeptide chain. Proteins are very diverse in shapes and sizes. The number and sequence of amino acids that make up a protein are important in determining its shape because there are different types of amino acids such as acidic, basic, and neutral amino acids.

Macromolecules Proteins These different chemical properties of amino acids cause them to attract and repel each other in different ways. The three-dimensional (3D) shape of the protein is very important to the functioning of the protein and if the sequence of amino acids in the protein is changed, the protein might fold differently and lose its ability to perform its function.

Macromolecules Proteins The most common examples of proteins are the enzymes and hormones. Enzymes that are extremely important proteins which changes the rate of a biochemical reaction such as salivary amylase. Hormones that are biochemical signals that released by endocrine cells and control specific processes, such as growth, development, metabolism, and reproduction. Insulin is one of the most common example of hormones.

Macromolecules Nucleic acids The nucleic acids are the genetic material that store cellular information. The nucleic acids are polymers that made of small building blocks which called nucleotides. Nucleotides composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms arranged in three attached molecules that are nitrogenous base, ribose sugar, and three phosphate groups.

Two types of nucleic acids: DNA (Deoxyribonucleic acid) Macromolecules Two types of nucleic acids: DNA (Deoxyribonucleic acid) DNA is the main copy of an organism’s information code that consists of two strands of nucleotides. This double-stranded molecule contains the instructions used to create enzymes and structural protein. Consequently, DNA molecules are the genetic code which regulates how an organism looks and acts.

Two types of nucleic acids: RNA (Ribonucleic acid) Macromolecules Two types of nucleic acids: RNA (Ribonucleic acid) RNA is another important nucleic acid molecule that forms a message or a copy of DNA that utilized to making proteins. Unlike the DNA molecule the RNA is usually single-stranded molecule. There are four major types of RNA: messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), and regulatory RNAs.

Macromolecules Summary The carbon atoms bond to each other in many ways to form various compounds. Polymers are large macromolecules that made up of repeating subunits called monomers. Polymers are synthesized by a chemical reaction called condensation reaction. There are four major types of macromolecules: carbohydrates, proteins, lipids and nucleic acids.