Types of Monomers | Sciencing
The carbohydrate monomers deoxyribose and ribose are integral parts of DNA and Consequently, we can define monosaccharides as possessing the molecular a sugar molecule varies, many monosaccharides are isomers of one another. glycosidic linkage between glucose monomers causes glycogen polymers to. When combined with other monomers, polymers are formed. Food in the forms of carbohydrates, proteins and fats derives from the linkage of several monomers. What Are the Chemical Names of the Four Macromolecules? Lipids with three fatty acid tails and one glycerol are called triacylglycerols. Homopolymers are polymers made by joining together monomers of the same Heteropolymers are polymers composed of more than one kind of monomer. very high pressure until it becomes what is known as low-density polyethylene. Carbon atoms can link to other carbon atoms to create long carbon strings that.
Cells use glucose for cellular respiration. Glucose forms the basis of many carbohydrates. Other simple sugars include galactose and fructose, and these also bear the same chemical formula but are structurally different isomers. The pentoses are simple sugars such as ribose, arabinose and xylose.
Combining the sugar monomers creates disaccharides made from two sugars or larger polymers called polysaccharides. For example, sucrose table sugar is a disaccharide that derives from adding two monomers, glucose and fructose.
Other disaccharides include lactose sugar in milk and maltose a byproduct of cellulose. An enormous polysaccharide made from many monomers, starch serves as the chief storage of energy for plants, and it cannot be dissolved in water.
Starch is made from a huge number of glucose molecules as its base monomer. Starch makes up seeds, grains and many other foods that people and animals consume. The protein amylase works to revert starch back into the base monomer glucose. Glycogen is a polysaccharide used by animals for energy storage. Glycogen differs from starch by having more branches. When cells need energy, glycogen can be broken down via hydrolysis back into glucose.
Long chains of glucose monomers also make up cellulose, a linear, flexible polysaccharide found around the world as a structural component in plants. Many animals cannot fully digest cellulose, with the exception of ruminants and termites. Another example of a polysaccharide, the more brittle macromolecule chitin, forges the shells of many animals such as insects and crustaceans. Simple sugar monomers such as glucose therefore form the basis of living organisms and yield energy for their survival.
Monomers of Fats Fats are a type of lipids, polymers that are hydrophobic water repellent. The base monomer for fats is the alcohol glycerol, which contains three carbons with hydroxyl groups combined with fatty acids.
Fats yield twice as much energy as the simple sugar, glucose. For this reason fats serve as a kind of energy storage for animals. Fats with two fatty acids and one glycerol are called diacylglycerols, or phospholipids. Lipids with three fatty acid tails and one glycerol are called triacylglycerols, the fats and oils.
Fats also provide insulation for the body and the nerves within it as well as plasma membranes in cells. Monomers of Proteins An amino acid is a subunit of protein, a polymer found throughout nature. An amino acid is therefore the monomer of protein.
Introduction to macromolecules
Proteins provide numerous functions for living organisms. Several amino acid monomers join via peptide covalent bonds to form a protein. Two bonded amino acids make up a dipeptide. Three amino acids joined make up a tripeptide, and four amino acids make up a tetrapeptide.
Science at a Distance
With this convention, proteins with over four amino acids also bear the name polypeptides. Of these 20 amino acids, the base monomers include glucose with carboxyl and amine groups. Glucose can therefore also be called a monomer of protein. The amino acids form chains as a primary structure, and additional secondary forms occur with hydrogen bonds leading to alpha helices and beta pleated sheets.
Folding of amino acids leads to active proteins in the tertiary structure. Additional folding and bending yields stable, complex quaternary structures such as collagen. Collagen provides structural foundations for animals. The protein keratin provides animals with skin and hair and feathers. Proteins also serve as catalysts for reactions in living organisms; these are called enzymes.
Proteins serve as communicators and movers of material between cells. For example, the protein actin plays the role of transporter for most organisms.
The varying three-dimensional structures of proteins lead to their respective functions. Changing the protein structure leads directly to a change in protein function.
Nucleotides as Monomers Nucleotides serve as the blueprint for the construction of amino acids, which in turn comprise proteins.
Nucleotides store information and transfer energy for organisms. Nucleotides are the monomers of natural, linear polymer nucleic acids such as deoxyribonucleic acid DNA and ribonucleic acid RNA. Nucleotide monomers are made of a five-carbon sugar, a phosphate and a nitrogenous base. Bases include adenine and guanine, which are derived from purine; and cytosine and thymine for DNA or uracil for RNAderived from pyrimidine. The combined sugar and nitrogenous base yield different functions.
Nucleotides form the basis for many molecules needed for life. One example is adenosine triphosphate ATPthe chief delivery system of energy for organisms. Adenine, ribose and three phosphate groups make up ATP molecules. Phosphodiester linkages connect the sugars of nucleic acids together.
These linkages possess negative charges and yield a stable macromolecule for storing genetic information. RNA, which contains the sugar ribose and adenine, guanine, cytosine and uracil, works in various methods inside cells.
RNA exists in a single-helix form. DNA is the more stable molecule, forming a double helix configuration, and is therefore the prevalent polynucleotide for cells. DNA contains the sugar deoxyribose and the four nitrogenous bases adenine, guanine, cytosine and thymine, which make up the nucleotide base of the molecule.
Polysaccharides are excellent energy storage molecules because they are easily built and broken down by enzymes. Forming fairly compact structures, polysaccharides allow energy storage without the space required by a pool of free glucose monomers.
Other polysaccharides form strong fibers that provide protection and structural support in both plants and animals. With small differences in the bond between monomers, polymers can function as compact energy storage units in starch and glycogen or as strong, protective fibers in cellulose and chitin.
- What is the relationship between monomers and polymers? Give an example using proteins.
Understanding the structure, synthesis, and breakdown of carbohydrate polymers provides a framework for understanding their function in living cells. Animals, including humans, create glucose polymers called glycogen.
The position of the glycosidic linkage between glucose monomers causes glycogen polymers to coil into spiral shapes. Glycogen polymers are significantly branched, with several monomers in the primary chain containing a second glycosidic linkage to a different glucose.
The second attachment sites allow shorter glucose chains to branch away from the main chain, packing more glucose units into the compact coiled structure. Animals initiate enzyme-driven hydrolysis reactions to break down glycogen when energy is needed. For quick access to energy, glycogen is stored primarily in two locations in humans, the liver for easy delivery into the bloodstream and muscles for direct use as needed. Plants synthesize two types of polysaccharides, starch and cellulose.
The glycosidic bonds between glucose units in plant starch are similar to those in animal glycogen. Accordingly, starch molecules are structurally similar, forming compact coils, and play a similar role in energy storage for plants. Unlike glycogen, starch molecules vary widely in the level of branching. Most plants form a mixture of starch polymers with little to no branching and polymers with extensive branching. In addition to providing energy for the plants that synthesize them, starches serve as the main food source for many animals.
Humans and other animals produce enzymes that degrade starch molecules into small fragments during digestion. In humans, this digestion begins in the mouth by an enzyme called amylase, which degrades starch polymers into disaccharides maltose.
To experience starch digestion yourself, try chewing an unsalted cracker for a long time.