Inner+Fish+Unit+MV

Molly Vaughn August 19, 2008 Human Biology

2.3 Molecules of Life (p.27) Define... Organic molecules- Organic molecules are separated into four categories, which are called carbohydrates, lipids, proteins, and nucleic acids. - Its carbon and it was something that was alive. 1. What are the four classes of molecules unique to cells? - The four classes of molecules unique to cells are called carbohydrates, lipids, proteins, and nucleic acids. 2. What type of reaction occurs during the synthesis of macromolecules? - A dehydration reaction occurs during the synthesis of macromolecules. When this occurs it removes all the water and brings the molecules together. 2.4 Carbohydrates (p. 28-29) Define... Monosaccharide- A monosaccharide is also known as a simple sugar and it is formed if the number of carbon atoms in a carbohydrate is low. Disaccharide- A disaccharide is made by joining only two monosaccharides together by a dehydration reaction. Glucose- Glucose, the hexose our bodies need use as an immediate source of energy. Polysaccharide- Polysaccharides are macromolecules such as starch, glycogen, and cellulose that contain many glucose units. Starch- Starch is readily stored forms of glucose in plants and animals. Starch are long chains of up to 4,000 glucose units, however, it has fewer side branches, or chains, of glucose that branch off from the main chain. Glycogen- Glycogen is readily stored in forms of glucose in plants and animals. Glycogen has more side branches, or chains, of glucose that branches off from the main chain than does starch. Cellulose- Cellulose if found in plant cell walls. In cellulose, the glucose units are joined by a slightly different type of linkage than that in starch or glycogen. Cellulose largely passes through our digestive tract as fiber, or roughage. 1. What is the usual function of carbohydrates in humans? - Carbohydrate’s function is used for quick and short-term storage. 2. What is the difference between a simple carbohydrate and the various complex carbohydrates? - Simple carbohydrates are called simple sugars or monosaccharide, which are formed if the number of carbon atoms in a carbohydrate is low. Complex carbohydrates are polysaccharides that have macromolecules such as starch, glycogen, and cellulose that contain many glucose units. 3. Of what benefit is fiber in our diet? - Insoluble fiber adds bulk to fecal material, which stimulates movements of the large intestine, preventing constipation. Soluble fiber combines with cholesterol in the small intestine and prevents it from being absorbs. Fiber is also said to prevent heart disease and cancer in some cases. 2.5 Lipids 1. Define saturated fats, unsaturated fat, and trans fat. - Saturated fats: Saturated fats have no double bonds between the carbon atoms. The chain is saturated, so to speak, with all the hydrogen’s it can hold. - Unsaturated fat: Unsaturated fat is a molecule that has one or more double bonds between the atoms of its carbon chain. - Trans fat: Fats, which occur naturally in meat and dairy products of ruminants, that are also industrially created through partial hydrogenation of plant oils and animal fats. 2. What is the main function of fats and oils and what are they composed of? - The main function of fats and oils are for long-term energy storage, it insulates against heat loss, and it forms a protective cushion around major organs. Fats are composed of lard and butter. Oils are composed of corn oil and soybean oil. 3. What are the uses of phospholipids and steroids in the body? - A phosepholipid is a molecule that forms the bilayer of the cell’s membranes; has a polar, hydrophilic head bonded to two nonpolar, hydrophobic tails. A steroid is a type of lipid molecule having a complex of four carbon rings. 2.6 Proteins (p. 32-34) Define peptide bond, and denaturation - Peptide bond: A peptide bond is a type of covalent bond that joins to amino acids. - Denaturation: Denaturation is a loss of normal shape by an enzyme so that it no longer functions; caused by a less than optimal pH or temperature. 1. What are the major functions of proteins in an organism? - Proteins are of primary importance in the structure and function of cells. 2. How does an amino acid get its name? - The name amino acid is appropriate because one of the groups is an-NH2 and another is a-COOH. 3. How does the shape of a protein relate to its function? - Proteins cannot function unless they have their usual shape and once a protein loses its normal shape, it is no longer able to perform its usual function.