Conversation - Fourth Grade - Exam

CARBOHYDRATES Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen in a ratio of about one carbon atom to two hydrogen atoms to one oxygen atom. The number of carbon atoms in a carbohydrate varies. Some carbohydrates serve as a source of energy. Other carbohydrates are used as structural materials. Carbohydrates can exist as monosaccharides, disaccharides, or polysaccharides. Monosaccharides A monomer of a carbohydrate is called a monosaccharide (MAHN-oh-SAK-uh-RIED). A monosaccharide—or simple sugar— contains carbon, hydrogen, and oxygen in a ratio of 1:2:1. The gen- eral formula for a monosaccharide is written as (CH2O)n, where n is any whole number from 3 to 8. For example, a six-carbon mono- saccharide, (CH2O)6, would have the formula C6H12O6. The most common monosaccharides are glucose, fructose, and galactose, as shown in Figure 3-6. Glucose is a main source of energy for cells. Fructose is found in fruits and is the sweetest of the monosaccharides. Galactose is found in milk. Notice in Figure 3-6 that glucose, fructose, and galactose have the same molecular formula, C6H12O6, but differing structures. The different structures determine the slightly different properties of the three compounds. Compounds like these sugars, with a single chemical formula but different structural forms, are called isomers (IE-soh-muhrz). SECTION 2 OBJECTIVES ● Distinguish between monosaccharides, disaccharides, and polysaccharides. ● Explain the relationship between amino acids and protein structure. ● Describe the induced fit model of enzyme action. ● Compare the structure and function of each of the different types of lipids. ● Compare the nucleic acids DNA and RNA. VOCABULARY carbohydrate monosaccharide disaccharide polysaccharide protein amino acid peptide bond polypeptide enzyme substrate active site lipid fatty acid phospholipid wax steroid nucleic acid deoxyribonucleic acid (DNA) ribonucleic acid (RNA) nucleotide C HO H C H OH C OH H C CH2OH H C H OH O Glucose C OH C O H OH C OH H CH2OH C H CH2OH Fructose C H HO C OH H C OH H C CH2OH H C H OH O Galactose Glucose, fructose, and galactose have the same chemical formula, but their structural differences result in different properties among the three compounds. FIGURE 3-6 Copyright © by Holt, Rinehart and Winston. All rights reserved. 56 CHAPTER 3 Disaccharides and Polysaccharides In living things, two monosaccharides can combine in a condensa- tion reaction to form a double sugar, or disaccharide (die-SAK-e-RIED). For example in Figure 3-4, the monosaccharides fructose and glu- cose can combine to form the disaccharide sucrose. A polysaccharide is a complex molecule composed of three or more monosaccharides. Animals store glucose in the form of the polysaccharide glycogen. Glycogen consists of hundreds of glucose molecules strung together in a highly branched chain. Much of the glucose that comes from food is ultimately stored in your liver and muscles as glycogen and is ready to be used for quick energy. Plants store glucose molecules in the form of the polysaccha- ride starch. Starch molecules have two basic forms—highly branched chains that are similar to glycogen and long, coiled, unbranched chains. Plants also make a large polysaccharide called cellulose. Cellulose, which gives strength and rigidity to plant cells, makes up about 50 percent of wood. In a single cellu- lose molecule, thousands of glucose monomers are linked in long, straight chains. These chains tend to form hydrogen bonds with each other. The resulting structure is strong and can be broken down by hydrolysis only under certain conditions. PROTEINS Proteins are organic compounds composed mainly of carbon, hydrogen, oxygen, and nitrogen. Like most of the other biological macromolecules, proteins are formed from the linkage of monomers called amino acids. Hair and horns, as shown in Figure 3-7a, are made mostly of proteins, as are skin, muscles and many biological catalysts (enzymes). Amino Acids There are 20 different amino acids, and all share a basic structure. As Figure 3-7b shows, each amino acid contains a central carbon atom covalently bonded to four other atoms or functional groups. A single hydrogen atom, highlighted in blue in the illustration, bonds at one site. A carboxyl group, —COOH, highlighted in green, bonds at a second site. An amino group, —NH2, highlighted in yel- low, bonds at a third site. A side chain called the R group, high- lighted in red, bonds at the fourth site. The main difference among the different amino acids is in their R groups. The R group can be complex or it can be simple, such as the CH3 group shown in the amino acid alanine in Figure 3-7b. The differences among the amino acid R groups gives different proteins very different shapes. The different shapes allow pro- teins to carry out many different activities in living things. Amino acids are commonly shown in a simplified way such as balls, as shown in Figure 3-7c. (a) Many structures, such as hair and horns are made of proteins. (b) Proteins are made up of amino acids. Amino acids differ only in the type of R group (shown in red) they carry. Polar R groups can dissolve in water, but nonpolar R groups cannot. (c) Amino acids have complex structures, so, in this and other textbooks, they are often simplified into balls. FIGURE 3-7 (b) Alanine (an amino acid) (c) Simplified version of amino acid CH3 H N OH C C H O H (a) Copyright © by Holt, Rinehart and Winston. All rights reserved. BIOCHEMISTRY 57 H H N C C OH H O H CH3 H2O Glycine Alanine H N OH C C H O H H H N C C H O H CH3 N OH C C H O H (a) (b) (a) The peptide bond (shaded blue) that binds amino acids together to form a polypeptide results from a condensation reaction that produces water. (b) Poly- peptides are commonly shown as a string of balls in this textbook and elsewhere. Each ball represents an amino acid. FIGURE 3-8 Substrate Products Enzyme 1 2 3 In the induced fit model of enzyme action, the enzyme can attach only to a substrate (reactant) with a specific shape. The enzyme then changes and reduces the activation energy of the reaction so reactants can become products. The enzyme is unchanged and is available to be used again. 3 2 1 FIGURE 3-9 Dipeptides and Polypeptides Figure 3-8a shows how two amino acids bond to form a dipeptide (die-PEP-TIED). In this condensation reaction, the two amino acids form a covalent bond, called a peptide bond (shaded in blue in Figure 3-8a) and release a water molecule. Amino acids often form very long chains called polypeptides (PAHL-i-PEP-TIEDZ). Proteins are composed of one or more polypep- tides. Some proteins are very large molecules, containing hun- dreds of amino acids. Often, these long proteins are bent and folded upon themselves as a result of interactions—such as hydrogen bonding—between individual amino acids. Protein shape can also be influenced by conditions such as temperature and the type of solvent in which a protein is dissolved. For exam- ple, cooking an egg changes the shape of proteins in the egg white. The firm, opaque result is very different from the initial clear, runny material. Enzymes Enzymes—RNA or protein molecules that act as biological catalysts—are essential for the functioning of any cell. Many enzymes are proteins. Figure 3-9 shows an induced fit model of enzyme action. Enzyme reactions depend on a physical fit between the enzyme molecule and its specific substrate, the reactant being catalyzed. Notice that the enzyme has folds, or an active site, with a shape that allows the substrate to fit into the active site. An enzyme acts only on a specific substrate because only that substrate fits into its active site. The linkage of the enzyme and substrate causes a slight change in the enzyme’s shape. The change in the enzyme’s shape weakens some chemical bonds in the substrate, which is one way that enzymes reduce activation energy, the energy needed to start the reaction. After the reaction, the enzyme releases the products. Like any catalyst, the enzyme itself is unchanged, so it can be used many times. An enzyme may not work if its environment is changed. For example, change in temperature or pH can cause a change in the shape of the enzyme or the substrate. If such a change happens, the reaction that the enzyme would have catalyzed cannot occur.

Richard Bland College (RBC), Virginia’s selective, two-year, residential, liberal arts transfer institution, was born through innovation. In 1959, years before the Virginia Community College system was imagined, Frank Ernst – a Gateway region native, entrepreneur, and retired executive of Hopewell’s Allied Chemical Plant – proposed the creation of an institution grounded in the liberal arts tradition with opportunities for specialized training in in-demand fields such as engineering to the State Council of Higher Education. After discussions with Virginia Tech and the University of Virginia, Ernst found a willing partner in the College of William & Mary, the second-oldest university in the United States, who founded Richard Bland College in 1960. RBC has since offered multiple certificates and university-parallel two-year degrees. The College was named for the Virginia statesman and champion of public rights, Richard Bland. Son and grandson of successful planters, Richard Bland was educated at The College of William and Mary. From 1742 until his death in 1776, he represented the area in which the College is now located, first in the House of Burgesses, and later, with the adoption of a state constitution, in the House of Delegates. He also served as a delegate from Virginia in both the First and Second Continental Congresses. It seems fitting, therefore, that an institution of higher learning located in an area served for so many years by this distinguished Virginia patriot and scholar, should derive its name from one whom Jefferson described “as the most learned and logical man of those who took prominent lead in public affairs.” Before the Civil War, the property on which the College is now located was a plantation owned by the Gurley family. It became an important part of the Union-occupied territory during the 1864-1865 Siege of Petersburg. The present campus was the scene of two battles during that campaign. Shortly after the turn of the century, Hatcher Seward established a dairy and cattle farm on the former Gurley property and constructed two farmhouses. Today they serve as the President’s residence and the Hospitality House. In the early 1900s, the still-beautiful grove of pecan trees was planted. The farm was used as a work camp for about twenty conscientious objectors during World War I. The Commonwealth of Virginia authorized Central State Hospital to purchase the land in 1932 for use as the Petersburg Training School and Hospital for African-American Youth. That institution was moved in 1959, and the land, still owned by the Commonwealth, became the location for the establishment of Richard Bland College of The College of William and Mary. Under the guidance of Colonel (Ret.) James M. Carson, the former hospital and training facility was transformed into Richard Bland College, and classes were held beginning in 1961. In the late 1960s, Ernst Hall (named for a local business leader influential in the establishment of the college) was added to the original campus. In addition, a Student Center Library building and a gymnasium also were constructed in the early 1970s. Colonel Carson retired as the founding President of the College in 1973. From 1973 through 1975, Dr. Cornelius Laban, Professor of Biology, Emeritus, served as the Acting President of Richard Bland College. In 1975, Dr. Clarence Maze succeeded Colonel Carson as Richard Bland College’s second President. During his tenure, Richard Bland College expanded its academic programs, added an Asian water garden that was designed by Dr. Maze and expanded international programs and travel. In recognition of his service to the College, the renovated administration building was named Maze Hall upon his retirement in 1996. In 1996, Dr. James B. McNeer succeeded Dr. Clarence Maze as Richard Bland College’s third President. Dr. McNeer introduced a residential life program and oversaw the addition of the Residential Village in 2008. The Residential Village was comprised of two dormitories, Freedom Hall and Patriot Hall, which housed 250 students. A new Science and Technology Building was added in 2010, and in recognition of his service to the College, this building was named James B. McNeer Hall. Dr. McNeer retired in 2012. In 2012, Dr. Debbie L. Sydow succeeded Dr. James McNeer as Richard Bland College’s fourth president. Dr. Sydow expanded the reach, range and diversity of students attending Richard Bland College. She oversaw a physical campus transformation through extensive building renovation and new construction, creation of a Business Innovation Park, and conservation of the iconic pecan grove and water garden. President Sydow reinstituted intercollegiate athletics in 2013 and has since hailed three NJCAA national championship teams. She supported the Foundation’s emergence as a vibrant, entrepreneurial organization led by a Board of Directors composed largely of alumni, and she secured the largest private gift in College history to launch the W&M Promise Scholars program. By effectively leveraging partnerships, President Sydow boosted work-based learning and expanded academic and career pathways for students.

Conversation

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Conversation in French Greetings • Bonjour – Good morning/Hello • Salut – Hi/Bye • Bonsoir – Good evening • Allô – Hello (on the phone) • Bon après-midi – Good afternoon How Are You? • Comment ça va? – How are you? • Ça va? – How’s it going? I’m Feeling… • Ça va bien – I’m feeling good • Ça va mal – I’m feeling bad • Comme ci, comme ça – I’m feeling so-so • Ça va très bien – I’m feeling very good • Ça va très mal – I’m feeling very bad My Name Is… • Je m’appelle… – My name is… What’s Your Name? • Comment t’appelles-tu? – What’s your name? I’m This Old • J’ai ** ans – I am ** years old How Old Are You? • Quel âge as-tu? – How old are you? I Live Here • J’habite à… – I live in… Where Do You Live? • Où habites-tu? – Where do you live? Can I Borrow… • Puis-je emprunter…? – Can I borrow…? Goodbyes • Au revoir – Goodbye • À bientôt – See you soon • À demain - See you tomorrow • À lundi - See you Monday • Bonne nuit – Good night • Bonne soirée – Have a good evening

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