Question

essentials of human anatomy and physiology
60
and vitamin d. like carbohydrates, the lipids are degraded by hydrolysis and synthesized by de - hydration synthesis.
d. proteins are constructed from building blocks called amino acids; 20 common types of amino acids are found in the body.
e. levels of protein structure include the amino - acid chain (1°), the alpha helix and beta - pleated sheet (2°), a helical structure superimposed on 2° structures (3°), and a globular structure formed by two or more polypeptide chains (4°). amino - acid sequence determines the proteins constructed.
f. fibrous, or structural, proteins are the basic structural materials of the body. globular proteins are also called functional proteins; examples of these include enzymes, some hormones, and hemoglobin. disruption of the hydrogen bonds of functional proteins leads to their denaturation and inactivation.
g. enzymes increase the rates of chemical reactions by combining specifically with the reactants and holding them in the proper position to interact. they do not become part of the product. many enzymes are produced in an inactive form or are inactivated immediately after use.
h. nucleic acids include deoxyribonucleic acid (dna) and ribonucleic acid (rna). the building unit of nucleic acids is the nucleotide; each nucleotide consists of a nitrogen - containing base, a sugar (ribose or deoxyribose), and a phosphate group. dna (the \stuff\ of the genes) maintains genetic heritage by replicating itself before cell division and specifying protein structure. rna acts in protein synthesis to ensure that instructions of the dna are executed.
i. atp (adenosine triphosphate) is the universal energy compound used by all cells of the body. when energy is liberated by the oxidation of glucose, some of that energy is captured in the high - energy phosphate bonds of atp molecules and is stored for later use.
review questions
multiple choice
more than one choice may apply.

1. which of the following is (are) true concerning the atomic nucleus?

a. contains the mass of the atom.
b. the negatively charged particles are here.
c. particles can be ejected.
d. contains particles that determine atomic number.
e. contains particles that interact with other atoms.

1. pick out the correct match(es) of element and number of valence - shell electrons.

a. oxygen—6
d. nitrogen—3
b. chlorine—8
c. phosphorus—5
e. carbon—4

1. important functions of water include which of the following?

a. provides cushioning
b. acts as a transport medium
c. participates in chemical reactions
d. acts as a solvent for sugars, salts, and other solutes
e. reduces temperature fluctuations

1. alkaline substances include

a. gastric juice
d. lemon juice
b. water
c. blood
e. ammonia

1. glucose is to starch as

a. a steroid is to a lipid.
b. a nucleotide is to a nucleic acid.
c. an amino acid is to a protein.
d. a polypeptide is to an amino acid.

1. what lipid type is stored in fat deposits beneath the skin?

a. triglyceride
d. phospholipid
b. steroid
e. prostaglandin
c. vitamin d

1. absence of which of the following nitrogen - containing bases would prevent protein synthesis?

a. adenine
d. thymine
b. cytosine
e. uracil
c. guanine

1. atp is not associated with

a. a basic nucleotide structure.
b. high - energy phosphate bonds.
c. deoxyribose.
d. inorganic phosphate.
e. reversible reactions.

1. the element essential for normal thyroid function is

a. iodine.
d. selenium.
b. iron.
e. zinc.
c. copper.

Explanation:

Step1: Analyze question 1

The atomic nucleus contains most of the atom's mass and particles can be ejected (as in radioactive decay). Negatively - charged particles (electrons) are outside the nucleus. So, a and c are correct.

Step2: Analyze question 2

Oxygen has 6 valence - shell electrons. Chlorine has 7 valence - shell electrons, phosphorus has 5, nitrogen has 5, and carbon has 4. So, a is correct.

Step3: Analyze question 3

Water provides cushioning, acts as a transport medium, participates in chemical reactions, acts as a solvent for sugars, salts, and other solutes, and reduces temperature fluctuations. So, a, b, c, d, e are correct.

Step4: Analyze question 4

Alkaline substances have a pH greater than 7. Ammonia is an alkaline substance. Gastric juice is acidic, water is neutral, and blood has a slightly alkaline pH but ammonia is a more typical alkaline substance among the options. So, e is correct.

Step5: Analyze question 5

Glucose is a monomer of starch, and a nucleotide is a monomer of a nucleic acid, similar to the relationship of glucose to starch. So, b is correct.

Step6: Analyze question 6

Triglycerides are stored in fat deposits beneath the skin. So, a is correct.

Step7: Analyze question 7

Adenine, cytosine, guanine, and uracil are involved in RNA - related protein synthesis, and adenine, cytosine, guanine, and thymine are involved in DNA - related processes. Absence of adenine would prevent protein synthesis as it is part of nucleotides in both DNA and RNA and also in ATP which is needed for protein synthesis reactions. So, a is correct.

Step8: Analyze question 8

ATP has a basic nucleotide structure (adenosine + phosphate groups), high - energy phosphate bonds, and is involved in reversible reactions. It does not contain deoxyribose. So, c is correct.

Step9: Analyze question 9

Iodine is essential for normal thyroid function as it is used in the synthesis of thyroid hormones. So, a is correct.

Answer:

1. A. Contains the mass of the atom, C. Particles can be ejected
2. A. Oxygen—6
3. A. Provides cushioning, B. Acts as a transport medium, C. Participates in chemical reactions, D. Acts as a solvent for sugars, salts, and other solutes, E. Reduces temperature fluctuations
4. E. ammonia
5. B. a nucleotide is to a nucleic acid
6. A. Triglyceride
7. A. Adenine
8. C. deoxyribose
9. A. iodine