Explain the relationship between monomers and polymers. | pdl-inc.info
Discuss biological macromolecules and the differences between the four Lipids (polymers of lipid monomers); Nucleic acids (DNA and RNA; polymers of nucleotides). Let's take a closer look at the differences between the difference classes. major classes of biological macromolecules (carbohydrates, lipids, proteins. Biological macromolecules, the large molecules necessary for life, include of biological macromolecules are carbohydrates, lipids, proteins, and nucleic acids. Typically all the monomers in a polymer tend to be the same, or at least very . that links the two monomeric sugars (monosaccharides) together to form the. -Amino acids make up proteins (so even though there are only 22 natural amino acids, there are countless types of protein that are formed with.
More about phospholipids when we cover membrane structure. Steroids Steroids are also lipids but they have a carbon skeleton of four connected rings no glycerol here 3. The different properties of different steroids are due to the attached functional groups. Cholesterol is a steroid that can be modified to form many hormones. Proteins Proteins are extremely important. They are large, complex molecules that are used for structural support, storage, to transport substances, and as enzymes.
They are a sophisticated, diverse group of molecules, and yet they are all polymers of just 20 amino acids. Amino acids have a carbon attached to a hydrogen, an amino group, a carboxyl group and something else R.
Its the something else that give the amino acid its characteristics 3. Amino acids are joined together by peptide bonds dehydration synthesis 3. Polypeptide chains are strings of amino acids, joined by peptide bonds. Proteins are formed by twisting up one or more poly peptide chains. It is the shape, or conformation, of the protein that gives it its properties. There are four levels of protein structure. Primary structure is the unique series of amino acids.
The secondary structure results from hydrogen bonds along the chain which cause repeated coiled or folded patterns. The tertiary structure is superimposed on the secondary structure. It is the irregular contortions formed by bonding between the R groups. Some R groups of amino acids have sulfhydryl groups which bond together to for disulfide bridges. Quaternary structure results when the protein is made up of more than one polypeptide subunits for example hemoglobin, which has four polypeptide subunits.
Quaternary structure is the relationship of these subunits. Figure on pg 45 for summary When a protein's structure has been altered we say it has been denatured. Denaturing occurs when the hydrogen bonds that are holding parts of the molecule to other parts come apart. Usually as a result of exposure to extremes of pH or heat. Some denaturing is reversible some is irreversible. Cooking eggs denatures the proteins in the egg whites.
They cannot be uncooked. A high fever can denature proteins enzymes in the human body which can be fatal. Later we will learn in more detail the roles these nucleic acids play in protein synthesis. Nucleotides are made of three parts: The pentose sugar of DNA is deoxyribose. The pentose sugar of RNA is ribose. Subcellular structures are called organelles. Cytology is the study of cell structure. The cell's "anatomy" is referred to as its ultrastructure.
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.
- What Are Monomers?
- Monomers in Nature
- Nucleotides polymerize to yield nucleic acids.
An amino acid is therefore the monomer of protein. 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. 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. Be aware of this structure, know where it is found in the gene at control regions and its effect on gene expression, and that it is the subject of promising clinical investigations.
Properties of the peptide bond dominate the structures of proteins. The first of these properties is that the peptide bond has partial double character. Partial double character is conferred by the electronegative carbonyl oxygen, which draws the unshared electron pair from the amide hydrogen.
As a result of having double bond character the peptide bond is planar not free to rotate more stable in the trans configuration than in the cis These characteristics restrict the three-dimensional shapes of proteins because they must be accommodated by any stable structure. The second major property of the peptide bond is that the atoms of the peptide bond can form hydrogen bonds. Now let's look at some of the structures that accommodate the restrictions imposed by the peptide bond.
The first is the alpha-helix. The alpha-helix is a major structural component of proteins. The hydrogen bonds are all intrachain, between different parts of the same chain. A lthough a single hydrogen bond is weak, cooperation of many hydrogen bonds can be strongly stabilizing. Alpha-helices must have a minimum length to be stable so there will be enough hydrogen bonds. All peptide bonds are trans and planar. So, if the amino acid R-groups do not repel one another helix formation is favored.
The net electric charge should be zero or low charges of the same sign repel. Adjacent R-groups should be small, to avoids steric repulsion. R-groups that repel one another favor extended conformations instead of the helix.
Examples include large net electric charge and adjacent bulky R-groups. Proline is incompatible with the alpha-helix.
How are monomers, polymers, and macromolecules related to each other?
The ring formed by the R-group restricts rotation of a bond that would otherwise be free to rotate. The restricted rotation prevents the polypeptide chain from coiling into an alpha-helix. Occurrence of proline necessarily terminates or kinks alpha-helical regions in proteins. Occurrence of the alpha-helix. A component of typical globular proteins. A component of some fibrous proteins, like alpha-keratin. Alpha-keratin has high tensile strength, as first observed by Rapunzel.
It is found in hair, feathers, horn; the physical strength and elasticity of hair make it useful in ballistas, onagers, etc. The beta-pleated sheet is a second major structural component of proteins. The beta-pleated sheet resembles cellulose in that both consist of extended chains -- degenerate helices -- lying side by side and hydrogen bonded to one another.
The polypeptide chains of a beta-pleated sheet can be arranged in two ways: An edge-on view shows the pleats.
Stabilizing factors for the pleated sheet resemble those for the alpha-helix. The hydrogen bonds here are all interchain, unlike those of the alpha-helix. Small R-groups prevent steric destabilization.
Large R-groups destabilize due to crowding. Sheets can stack one upon the other, with interdigitating R-groups of the amino acids. Occurrence of the beta-pleated sheet. In some fibrous proteins. Egg stalks of certain moths. Collagen has an unusual structure. It consists of three polypeptide chains in a triple helix. This is the structure: Three extended helices of a type called polyproline II helices because polyproline can take this form hydrogen bonded to one another interchain ; no intrachain hydrogen bonds form because each helix is too extended, and hydrogen bonds cannot reach from one level of the helix up or down to the next level placed at the corners of a triangle.
The entire assembly is twisted into a superhelix. The stability of the collagen triple helix is due to its unusual amino acid composition and sequence.
One third of the amino acid residues is glycine, and the glycyl residues are evenly spaced: Gly X Y n, where X and Y are other amino acids is the amino acid sequence of collagen. This places a glycyl residue at each position where the chain is in the interior of the triple helix. There would be no room for a bulky R-group in this position glycine's R-group is H.
Explain the relationship between monomers and polymers.
The high glycine content with its small R-group would otherwise permit too much conformational freedom and favor a random coil. Proline and hydroxyproline together comprise about one third of the total amino acid residues, and Gly Pro Hypro is a common sequence. The relative inflexibility of the prolyl and hydroxyprolyl residues stiffens the chains.
Collagen occurs in tough, inelastic tissues, like tendon. The collagen helix is already fully extended. Unlike the alpha-helix, it cannot stretch; tendon ought not to stretch under heavy load. Collagen is the single most abundant protein in the body; fortunately collagen defects are rare.
Types of Monomers | Sciencing
Tertiary structure is the three dimensional arrangement of helical and nonhelical regions of macromolecules. Let's look first at the Tertiary structure of nucleic acids. Most circular double-stranded DNA is partly unwound before the ends are sealed to make the circle.
Partial unwinding is called negative superhelicity. Overwinding before sealing would be called positive superhelicity. Superhelicity introduces strain into the molecule. Think of holding a coil spring by the two ends and twisting it to unwind it; it takes effort to introduce this strain The strain of superhelicity can be relieved by forming a supercoil. The identical phenomenon occurs in retractable telephone headset cords when they get twisted.
The twisted circular DNA is said to be supercoiled. The supercoil is more compact. This is exemplified by yeast tRNA. There are four regions in which the strand is complementary to another sequence within itself. These regions are antiparallel, fulfilling the conditions for stable double helix formation.
How are monomers, polymers, and macromolecules related to each other? | Socratic
X-ray crystallography shows that the three dimensional structure of tRNA contains the expected double helical regions. Large RNA molecules have extensive regions of self-complementarity, and are presumed to form complex three-dimensional structures spontaneously. Tertiary structure in Proteins The formation of compact, globular structures is governed by the constituent amino acid residues.