Chapter 2: Section 2.3 Review Sheet Review Questions 1. What is the relationship between a polymer and a monomer (write your own analogy for the formation of a polymer from monomers)? A polymer is a large molecule made up of smaller units, called monomers, which are linked together. One analogy could be a string of Christmas lights – each light is a monomer and linked together they form a polymer. 2. What elements make up a carbohydrate? Carbon, hydrogen and oxygen (each glucose monomer is made up of 6 carbon, 12 hydrogen, and 6 oxygen atoms. 3. Carbohydrates are polymers, from what monomers are they made? They are made from the monomer glucose (a simple sugar). 4. Explain how the bonding properties of carbon atoms result in the large variety of carbon-based molecules in living things? Carbon has 4 electrons in its outer shell, thus it can form covalent bonds (a bond in which electrons are shared with another atom producing a really strong bond) with four different atoms at a time. 5. What is a lipid? What is it made of? Where do you find it in the cell? Lipids are nonpolar molecules that include fats, oils, and cholesterol. Lipids typically contain chains of carbon atoms bonded to oxygen and hydrogen atoms. Fats and oils are two types of lipids. - Lipids are a major component of all cell walls. 6. How is a saturated fatty acid different from an unsaturated fatty acid? Saturated fats contain fatty acids in which all carbon-carbon bonds are single bonds. Unsaturated fats have fatty acids with at least one carbon-carbon double bond. 7. Compare and contrast, how are carbohydrates and lipids similar? How are they different? Both of them are made of carbon, hydrogen, and oxygen; both are broken down as a source of energy; and both have some structural functions in organisms. Differences include: carbohydrates are sugars and starches and lipids are fats and oils. 8. What is a protein (what is it made of)? What kinds of bonds link the protein monomers in a protein? A protein is made of amino acid monomers that are linked together by bonds call peptide bonds. Proteins are involved in a wide variety of bodily functions including movement, eyesight, digestion, and cognition (to name a few). 9. What is a nucleic acid (name the two mentioned in the book)? From what type of monomer are they made? Two types of nucleic acids are DNA (what our genes are made of – our genetic code) and RNA. Nucleic acids are polymers made from monomers called nucleotides. Nucleotides are composed of a sugar, a phosphate group, and a nitrogen-containing base. 10. What is the relationship between proteins and nucleic acids (hint, one is responsible for building the other)? Nucleic acides have just one function. They work together to make proteins. DNA stores the information for putting amino acids together to make proteins – RNA helps to build the proteins (translating the genetic code in DNA into proteins). 11. What is a hydrogen bond? How do they form? (from Section 2.2) A hydrogen bond is an attraction between a slightly positive hydrogen atom and a slightly negative atom (found among water molecules – between oxygen and hydrogen – and in nucleic acids between hydrogen and nitrogen). Hydrogen bonds are weak compared with covalent bonds (found in carbon molecules). 12. What is pH? What is an acid? What is a base? (from Section 2.2) pH is a scale that measures the concentration of Hydrogen ions in a solution. Acids are compounds that release a hydrogen ion when it dissolves in water. Bases are compounds that remove Hydrogen ions from a solution. See book page 43 for more on the pH scale at its meaning.