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Chemical Composition of the Body and Enzyme Function
Study Guide, Chapter 2 and 4
Part I. Clinical Applications
1. It is determined that a patient is in acidosis. What does this mean, what is the normal pH range
for the human body, and would you treat the condition with a chemical that would raise or
lower the pH?
Acidosis means blood pH is below the normal range. Normal pH range is 7.35 to 7.45. The
patient should be treated with something to raise the pH
2. Johnny’s body temperature is spiking upward. When it reaches 104 F, his mother puts a call to
the pediatrician. She is advised to give Johnny Children’s acetaminophen or ibuprofen and
sponge his body with cool water to prevent a further rise in temperature. How might a fever
(excessively high body temperature) be detrimental to Johnny’s welfare?
“Normal” body temperature for an adult taken orally is 98.6°F (37°C) and many of our enzymes
functional well at that temperature. Heat increases the kinetic energy of molecules. Vital
biological molecules, like enzymes, can have their structure altered and rendered
nonfunctional by excessive heat. All biological enzymes are proteins and their destruction is
lethal because many key enzymatic reactions for life would be stopped.
3. Stanly has indigestion and is doubled over with pain. How could an antacid reduce his
stomach discomfort?
Stomach discomfort is frequently caused by excess stomach acidity (“acid indigestion”). An
antacid contains a weak base that will neutralize the excess acid (H+).
4. How can the rapid breakdown of fat result in a dangerous decrease in blood pH? Hint – Ketone
bodies
Hydrolysis of triglycerides within adipose tissue releases glycerol and free fatty acids into the
blood which are both used as an energy source by many organs; they can also be converted
by the liver into derivatives called ketone bodies which circulate through the blood and used as
an energy source by organs such as the heart and brain. Ketone bodies include acetoacetic
acid, β–hydroxybutryric acid, and acetone (solvent in nail polish remover). A rapid
breakdown of fat (lipolysis), as may occur during low-carbohydrate diets and in uncontrolled
diabetes mellitus, can result in elevated levels of ketone bodies in the blood – a condition
called ketosis. If there are sufficient amounts of ketone bodies in the blood to lower the blood
pH, the condition is called ketoacidosis. Severe ketoacidosis, which may occur in diabetes
mellitus, can lead to coma and death. A person in this condition may also have a sweetsmelling breath due to the presence of acetone, which is volatile and leaves the blood in the
exhaled air.
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Part II
1. O
2. C
3. K
4. I
5. H
6. N
7. Ca
8. Na
9. P
10. Mg
11. Cl
12. Fe
13. monosaccharides
14. Fatty acids and glycerol
15. amino acids
16. nucleotides
17. proteins
18. monosaccharides or carbohydrates
19. lipids
20. carbohydrates or monosaccharides
21. lipids
22. amino acids
23. nucleotides
24. nucleotides
25. lipids
26. proteins
27. carbohydrates
28. lipids
29. proteins
30. lipids
31. 2:1; C6H12O6; 2 hydrogens and 1 oxygen
32. collagen and keratin
33. enzyme and hemoglobin and certain
hormones
34. enzyme
35. starch
36. glycogen
37. DNA
38. Cholesterol (used to make all steroids)
and certain hormones
39. lactose and maltose
40. monosaccharide
41. functional proteins
42. nucleotide
43. fat
44. polysaccharide
45. polysaccharide
46. disaccharide
47. monosaccharide
48. monosaccharide
Part III
1. C
6. Ca
11. water
2. N
7. Cl
12. 10 times more
3. P
8. Na
13. 100 times more
4. Fe
9. 10
5. O
10. 4
14. antibodies, contraction, enzymes, certain hormones
15. nitrogen
16. monosaccharides; amino acids; 20; side chain; -NH2
17. adenine; ribose
18. triphosphate
19. ADP + P (phosphate)
20. Enzymes decrease the activation energy of a chemical reaction by orienting molecules
(substrate) so that they are more likely to react, and increase frequency of collisions.
21. proteins; substrate
22. active site; enzyme-substrate; substrate; enzyme
23. – ase ; dehydrogenase; water; fats (lipids); lactase
24. ions; vitamins ( or portions of vitamins)
25. nucleotide
26. adenine to thymine and cytosine to guanine
27. bases (A,C,T,G); 1,000; 40,000. Note: The haploid human genome contains approximately
20,000 protein-coding genes.
28. RNA is single stranded, its sugar is ribose and it contains the base uracil instead of thymine.
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Part IV
1. B
2. B
3. B
4. B
5. A
6. A
7. C
8. D
9. A
10. B, C
11. B
12. A
13. E
14. B
15. B
16. A, D
17. C, B
18. E, C
19. C, D
20. C
21. D
22. B
23. C
24. A
25. D
26. C
27. C
7. A
8. B
9. D
10. D
11. B
12. D
13. C
14. E
15. D
16. C
17. D
18. B
Part V
1.
2.
3.
4.
5.
6.
C
B
D
C
E
D
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Part VI
1. Which ion is responsible for increased acidity?
H+ is responsible for increased acidity.
2. What are monomers of carbohydrates called? Which monomer is blood sugar?
Monomers of carbohydrates are called monosaccharides or simple sugars. Glucose is blood
sugar.
3. What is the animal form of stored carbohydrate called?
The animal form of stored carbohydrate is glycogen
4. How do triglycerides differ from phospholipids in body function and location?
Triglycerides, the major source of stored energy in the body, are composed of three fatty acid
chains and a glycerol molecule and are found in fat tissue (adipose). Phospholipids consist of
two fatty acid chains and a charged phosphorus containing group. They are found in all cell
membranes and form the basis of those membranes.
5. What is the primary structure of proteins?
The primary structure of proteins is the linear sequence of amino acids composing the
polypeptide chain.
6. What are the two types of secondary structure in proteins?
The secondary structures of proteins are the alpha helix and the beta-pleated sheet. The alpha
helix structure resembles a Slinky toy or the coils of a telephone cord whereas a beta-pleated
sheet resembles ribbon-like structure such as an accordion’s bellows.
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7. How do DNA and RNA differ in the bases and sugars they contain?
DNA contains deoxyribose sugar and the bases A, T, G, C. RNA contains ribose sugar and the
bases A, U, G, C.
8. What are the two important roles of DNA?
DNA dictates protein structure by its base sequence and reproduces itself before a cell divides
to ensure that the genetic information in the daughter cells is identical
9. Describe the difference between competitive and non-competitive (allosteric) enzyme
inhibitors.
Competitive inhibition: The inhibitor competes for the same active site as the substrate
molecule. Non-competitive or allosteric inhibition: The inhibitor binds to an enzyme at a
location other than the active site causing the enzyme active site to change shape, thus
preventing its activity.
10. Name the types of pyrimidines and purines found in DNA. Name the types of pyrimidines and
purines found in RNA.
DNA contains the pyrimidines Thymine and Cytosine
DNA contains the purines Adenine and Guanine
RNA contains the pyrimidines Uracil and Cytosine
RNA contains the purines Adenine and Guanine
Part VII
1. Xanthomas
2. Phenylketonuria; Phenylketones or phenylpyruvic acid
3. Familial Hypercholesterolemia (FH); Homozygous; Heterozygous; Low-density lipoprotein;
Low-density lipoprotein; LDL or low density lipoproteins
4. Microcephaly
5. Aspartame
6. Familial Hypercholesterolemia (FH)
7. Phenylketonuria
8. Tay-Sachs Disease
9. Metabolism
10. Tay-Sachs Disease
11. Phenylketones (phenylpyruvic acid); tyrosine
12. Dopamine mostly and although not significant can have a decrease in norepinephrine
13. Glucose and galactose
14. Tyrosine
15. Albinism
16. Galactosemia
17. A