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Test Bank for Porth's Essentials of Pathophysiology
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5th edition
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TEST BANK L
, Tommie L. Norris: Porth's Essentials of Pathophysiology
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Chapter 1: Cell Structure and Function
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MULTIPLE CHOICE L
1. Although the basic structure of the cell plasma membrane is formed by a lipid bilayer,
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most ofthe specific membrane functions are carried out by:
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A) Bound and transmembrane proteins L L L
B) Complex, long carbohydrate chains L L L
C) Surface antigens and hormone receptors L L L L
D) A gating system of selective ion channels
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Ans: A L
Feedback:
The functions of plasma membrane depend on the presence of proteins that are bound in the lipid
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bilayer and some that have the ability to pass freely into and out of the cell.
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Carbohydrate chains form a cell coat that surrounds the membrane and that contain surface antigens
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and surface hormone receptors. Some ion channels are gated and open only when the membrane
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potential changes significantly.
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1. Which describes the function of the nucleus?L L L L L L
A) It is basically the site of protein synthesis in the body.
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B) It contains the genetic code for the individual.
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C) It is the transformer of cellular energy.
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D) It initiates the process of aerobic metabolism.
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Ans: B L
Feedback:
The nucleus contains DNA, which contains the genetic code that contains the information that
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controls cells. Ribosomes synthesize protein. Mitochondria transform organic compounds into
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cellular energy. Mitochondria require oxygen for aerobic metabolism, using hydrogen and
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carbon combined with oxygen molecules to form carbon dioxide and water as energy is released.
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2. Which of the following aspects of the function of the nucleus is performed by ribosomal
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Med C L
, RNA (rRNA)? L
A) Copying and carrying DNA instructions for protein synthesis
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B) Carrying amino acids to the site of protein synthesis
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C) Providing the site where protein synthesis occurs L L L L L L
D) Regulating and controlling protein synthesis L L L L
Ans: C L
Feedback:
There are three types of ribonucleic acid (messenger RNA, ribosomal RNA, and transfer RNA)
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that move to the cytoplasm and carry out the actual synthesis of proteins.
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Messenger RNA (mRNA) copies and carries the DNA instructions for protein synthesis to the
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cytoplasm; ribosomal RNA (rRNA) is the site of protein synthesis; and transfer RNA (tRNA)
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transports amino acids to the site of protein synthesis for incorporation into the protein being
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synthesized.
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3. Which accurately explains the functions of the organelles lysosomes? They:
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A) Are sacs filled with enzymes that breakdown and remove foreign substances and worn-
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out cell parts
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B) Function in association with the endoplasmic reticulum to modify protein end products
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and package them into secretory granules or vesicles
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C) Are small particles of nucleoproteins that are involved in the synthesis of proteins that
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remain in the cell as cytoplasmic structural or functional elements
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D) Are a dynamic system of interconnected membranous tubes that functions as a tubular
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communication system for transporting various substances from one part of the cell to another
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Ans: A L
Feedback:
Lysosomes are sacs that are filled with hydrolytic enzymes that aid in the processing and removal
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of unwanted substances within the cytoplasm. The Golgi apparatus functions in association with
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the endoplasmic reticulum to modify and package substances in preparation for secretion, whereas
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ribosomes are small particles of nucleoproteins that are involved in the synthesis of proteins. The
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ER is a tubular communication system for transporting various substances from one part of the
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cell to another.
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4. Impairment in the function of peroxisomes would result in: L L L L L L L L
Med C L
,