Embed Size (px)
Citation preview
Chapter 5: The Structure and Function of Large Biological Molecules
1. Name the four main classes of organic molecules found in all living things. Which of the four are classified as macromolecules. Define macromolecule. ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
2. What is a polymer? What is a monomer? Provide a specific example. ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
3. Monomers are connected in what type of reaction? What occurs in this reaction?
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
4. Polymers are converted to monomers in what type of reaction? ____________________________________________________________________________________________________________________________________
5. The root words of hydrolysis will be used many times to form other words you will learn this year. What does each root word mean? ____________________________________________________________________________________________________________________________________
6. Consider the following reaction: C6H12O6 + C6H12O6 à C12H22O11
a. The equation is not balanced; it is missing a molecule of water. Write it in on the correct side of the equation. b. Polymers are assembled and broken down in two types of reactions: dehydration synthesis and hydrolysis. Which kind of reaction is this? c. Is C6H12O6 (glucose) a monomer, or a polymer? d. To summarize, when two monomers are joined, a molecule of ____________________ is always removed. 7. What are the monomers of all carbohydrates? ________________________________________ 8. Most monosaccharides are some multiple of CH2O. For example, ribose is a 5-‐carbon sugar with the formula C5H10O5. It is a pentose sugar. (From the root penta–, meaning five.) What is the formula of a hexose sugar? 9. Here are the three hexose sugars. Label each of them. Notice that all sugars have the same two functional groups. Name them. ________________________ ________________________ ________________________ 10. As a quick review, all of the sugars in the figure above have the same chemical formula: C6H12O6. IMPORTANT: Change the structure, change the function! What term did you learn in Chapter 4 for compounds that have the same molecular formulas but different structural formulas?
11. Here is the abbreviated ring structure of glucose:
• Where are all the carbons? • Number them. • Circle the number 3 carbon. • Put a square around the number 5 carbon. • Is this alpha glucose or beta glucose? Why?
____________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________
12. What is a disaccharide? Three disaccharides have the formula C12H22O11. Name them below and complete the chart.
Disaccharide Formed from Which Two Monosaccharides? Found Where?
13. Have you noticed that all the sugars end in –ose? This root word means __________________________________.
14. What is a glycosidic linkage? ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
15. Here is a molecule of starch, which shows 1–4 glycosidic linkages of α-‐glucose monomers as well as 1–6 glycosidic linkages. Number the carbons in the first two sugars of this figure. Use this to explain what is meant by a 1–4 glycosidic linkage.
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
16. There are two categories of polysaccharides. Name them and give examples.
Type of Polysaccharide Examples
17. Why can you not digest cellulose? What organisms can? ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
18. Name the correct carbohydrate for each of the following:
• ________________________ Has 1–4 β glucose linkages
• ________________________ A storage polysaccharide made by vertebrates; stored in your liver
• ________________________ Two monomers of this form maltose
• ________________________ Glucose + ______ form sucrose
• ________________________ Monosaccharide commonly called “fruit sugar”
• ________________________ “Milk sugar”
• ________________________ Structural polysaccharide that gives cockroaches their crunch
• ________________________ Malt sugar; used to brew beer
• ________________________ Structural polysaccharide that comprises plant cell walls 19. Lipids include fats, waxes, oils, phospholipids, and steroids. What characteristic do all lipids share? _________________________________________________________________________________________________________________________ 20. What are the building blocks of fats? Label them on this figure. Label the ester linkages as well.
21. If a fat is composed of three fatty acids and one glycerol molecule, how many water molecules will be removed to form it? What is this process called?
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
22. Draw a fatty acid chain that is eight carbons long and is unsaturated. Circle the element in your chain that makes it unsaturated, and explain what this means.
23. Provide examples of both saturated fats and unsaturated fats. ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
24. Why are many unsaturated fats liquid at room temperature? ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________ 25. What is a trans fat? Why should you limit them in your diet? ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________ 26. List four important functions of fats. ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
27. Carefully examine the figure below of a phospholipid and complete the following:
• Label the sketch to show the phosphate group, the glycerol, and the fatty acid chains.
• Indicate the region that is hydrophobic and the region that is hydrophilic.
• Why are the “tails” hydrophobic?
_________________________________________________________________________________________________________________
_________________________________________________________________________________________________________________
• Which of the two fatty acid chains is unsaturated? Label it. How do you know it is unsaturated? _________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________
28. To summarize, a phospholipid has a glycerol attached to a phosphate group and two fatty acid chains. The head is hydrophilic, and the tail is hydrophobic. Now, sketch the phospholipid bilayer structure of a plasma membrane. Label the hydrophilic heads, hydrophobic tails, and location of water.
29. Why are the phospholipid tails all located in the interior of your plasma membrane?
____________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________
30. Some people refer to the structure shown in a cholesterol molecule as three hexagons and a doghouse. Cholesterol and other steroids all have this general shape. Name two other steroids.
______________________________________________________
______________________________________________________
31. Complete the following table summarizing protein functions. The 1st has been done for you!
Type of Protein Function Example Enzyme
Selective acceleration of chemical reactions.
Digestive enzymes such as amylase; Enzyme (Catalase) that breaks down H2O2 into H2O and O2
32. The monomers of proteins are amino acids.
• Sketch an amino acid below. Label the alpha (central) carbon, amino group, carboxyl group, and R group.
• What is represented by R? How many are there? _______________________________________________________________________________________________________________ _______________________________________________________________________________________________________________
• STUDY the 20 different amino acid models. Do you understand why some R groups are nonpolar, some polar, and others electrically charged (acidic or basic)? If you were given an R group, could you place it in the correct group?
33. Define the following terms:
ü Peptide bond
_______________________________________________________________________________________________________________
ü Dipeptide
_______________________________________________________________________________________________________________
ü Polypeptide
_______________________________________________________________________________________________________________
ü Dehydration synthesis:
_______________________________________________________________________________________________________________
34. Examine the figure to the right. Label the following:
ü peptide bond ü H20 ü alpha carbon ü amino group ü carboxyl group ü R group.
What process is this figure modeling? __________________________________________
35. There are four levels of protein structure. Summarize each level in the following table.
Level of Protein Structure Explanation
Primary
Secondary • α helix
• β pleated sheet
Tertiary
Quaternary
36. Label each of the levels of protein structure on this figure.
37. Enzymes are globular proteins that exhibit at least tertiary structure. Use the figure below to identify and explain each interaction that folds this protein fragment.
38. A very important concept in Biology is … a change in structure will change the function. Explain how this principle applies to sickle-‐cell disease. Why is the structure changed? _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ 39. Besides mutation, which changes the primary structure of a protein, protein structure can be changed by denaturation. Define denaturation, and give at least three ways a protein may become denatured. _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ 40. Chaperone proteins or chaperonins assist in the proper folding of proteins. Annotate the figure below to explain the process.
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
41. The flow of genetic information is from DNA àRNAà protein. Use the figure below to briefly explain the process. Label the nucleus, DNA, mRNA, ribosome, amino acids, polypeptide, and cytoplasm.
42. DNA and RNA are nucleic acids. A nucleic acid is composed of nucleotides. The components of a nucleotide are a 5-‐carbon sugar, a nitrogenous base, and a phosphate group. Carefully STUDY the figure below. • Circle the four nucleotides of the polynucleotide strand. • Label each nitrogenous base (on the right upper side of figure) and indicate which are purines and
which are pyrimidines. • Label deoxyribose and ribose (on the right lower side of figure). • Label the end of the polynucleotide strand that has a phosphate attached to a 5' carbon … 5' • Label the other end of the chain which has a hydroxyl group on a 3' carbon … 3'. • Label the three components of one nucleotide.
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________
43. Notice that there are five nitrogen bases.
• Which four are found in DNA? ___________________________________________________________________________
• Which four are found in RNA? ___________________________________________________________________________ 44. How do ribose and deoxyribose sugars differ?
_________________________________________________________________________________________________________________________
45. Examine and label the model of DNA that was proposed by James Watson and Francis Crick.
46. Our current understanding of many areas of biology has been transformed by genomics and proteomics. Explain each, and give an example of its application. _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ 47. Why can DNA and protein sequences serve as tape measures of evolution? _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________ _________________________________________________________________________________________________________________________
• What is this shape called? • Why are the strands said to be antiparallel? • What two molecules make up the “uprights”?
• What molecules make up the “rungs”?
• In a DNA double helix, a region along one DNA strand
has the sequence of nitrogenous bases shown below. Write the complementary strand. Indicate the 5' and 3' ends of the new strand.
5'-‐T A G G C C T-‐3'
