Module 7 Intro

Self-Check Answers

1. Carbohydrates, lipids, proteins, and nucleic acids make up the four categories of macromolecules. (answer 1)
   
   
2. The process that builds macromolecules is dehydration synthesis. (answer 2)
   
   
3. The process that breaks down macromolecules is hydrolysis. (answer 3)
   
   
4. Two types of carbohydrates are simple sugars and polysaccharides. Subunits of simple sugars include mono or disaccarides and they are composed of one or two glucose molecules, such as maltose. Polysaccharides contain more than two glucose molecules—an example is cellulose. (answer 4)
   
   
5. Subunits that make up fats are glycerol and three fatty acid molecules. (answer 5)
   
   
6. With saturated fats, all fatty acids contain single bonds between carbon atoms.  Meanwhile, with unsaturated fats, at least one of the fatty acids in the molecule contains a double covalent bond between two adjacent carbon atoms. (answer 6)
   
   
7. The subunits that make up proteins are amino acids. (answer 7)
   
   
8. Proteins are more structurally and functionally diverse than carbohydrates and lipids because of the R-group. Structurally, the combination of attraction and repulsion of different R-groups along a protein will result in a complex, three-dimensional structure. Functionally, since R-groups can be positively or negatively charged, proteins can be water soluble or water insoluble. Proteins such as enzymes are water soluble, while the proteins in your fingernails are insoluble, or they repel water. (answer 8)
   
   
9. An enzyme is a specific protein molecule in a biological system that increases the rate of a chemical reaction. (answer 9)
   
   
10. An enzyme lowers the energy required for a substrate molecule to react. By binding to the substrate, the enzyme weakens the bonds within the substrate, allowing it to become more reactive. This speeds up reactions. (answer 10)
    
    
11. An increase in temperature can increase the rate of enzyme binding to the substrate, allowing for an increase in the rate of reaction. However, if the temperature is too high, the enzyme can be damaged or denatured. This would slow or cease reactions. The pH can affect the shape of proteins. If an enzyme’s shape (particularly the active site) is altered due to pH, the ability of the substrate to bind to this area may be affected, altering the rate of reaction. (answer 11)