Genetic Engineering

I. With the use of bacterial restriction nucleases, segments of DNA can be cut from the DNA of one cell and inserted into the DNA of another cell— transfection—forming a transgenic organism.

II. Transfection of human genes into bacteria provides a mechanism for producing large quantities of the expressed protein, which can be isolated and used to treat disease (for example, the production of insulin).

III. Analysis of the pattern of tissue DNA fragments formed by nuclease digestion is the basis of DNA fingerprinting used to identify a specific individual.

IV. Experimental techniques that lead to the selective removal or inactivation of a specific gene produce a knockout organism that can be used to study the functional consequences of the loss of the gene's activity.

KEY TERMS

gene genome chromosome histone nucleosome transcription translation

"stop" signal messenger RNA (mRNA)

RNA polymerase template strand promoter codon primary RNA transcript exon intron spliceosome ribosomal RNA (rRNA)

transfer RNA (tRNA)

anticodon initiation factor chaperone transcription factor preinitiation complex

Vander et al.: Human Physiology: The Mechanism of Body Function, Eighth Edition

PART ONE Basic Cell Functions

5. Genetic Information and

Protein Synthesis

ubiquitin

centrosome

25.

Describe the mechanism of DNA repair.

proteosome

mitotic apparatus

26.

State the difference between a homozygote and a

signal sequence

cell division cycle kinase

heterozygote in terms of alleles.

autosome

cyclin

27.

Describe the difference between a phenotype that is

sex chromosome

growth factor

inherited as a dominant or recessive trait.

daughter cells

natural selection

28.

Describe the characteristics of a cancer cell.

DNA polymerase

allele

29.

Describe the difference between a benign and a

telomere

gene pool

malignant tumor.

telomerase

homozygous

30.

Describe the difference between an oncogene and a

proofreading

heterozygous

tumor suppressor gene.

interphase

genotype

31.

Describe the properties of bacterial restriction

mitosis

phenotype

nucleases and their role in gene transfection.

cytokinesis

dominant

32.

Describe the process of DNA fingerprinting.

sister chromatid

recessive

33.

How does the base sequence in a cDNA molecule

centromere

p53

differ from the base sequence in the gene from which

spindle fiber

it is derived?

REVIEW QUESTIONS

CLINICAL TERMS

10 11

Summarize the direction of information flow during protein synthesis.

Describe how the genetic code in DNA specifies the amino acid sequence in a protein.

List the four nucleotides found in mRNA.

Describe the main events in the transcription of genetic information in DNA into mRNA.

State the difference between an exon and an intron.

What is the function of a spliceosome?

Identify the site of ribosomal subunit assembly.

Describe the role of tRNA in protein assembly.

Describe the events of protein translation that occur on the surface of a ribosome.

What is the function of a chaperone?

Describe the effects of transcription factors on gene transcription.

List the factors that regulate the concentration of a protein in a cell.

What is the function of the signal sequence of a protein? How is it formed, and where is it located? Describe the pathway that leads to the secretion of proteins from cells.

Describe the functions of the Golgi apparatus. Describe the structure of chromatin, and state the number and types of chromosomes found in a human cell.

Describe the mechanism by which DNA is replicated.

What is a telomere, and what is its function? Summarize the main events of mitosis and cytokinesis.

Describe the role of cell division cycle kinases and cyclins in controlling cell division.

Describe the function of growth factors.

Describe several ways in which the genetic message can be altered by mutation.

How will the deletion of a single base in a gene affect the protein synthesized?

List the three general types of effects that a mutation can have on a cell's function.

CLINICAL TERMS

mutation

benign tumor

mutagen

metastasis

familial hypercho-

malignant tumor

lesterolemia

dysplasia

cystic fibrosis

carcinogen

single gene disease

oncogene

chromosomal disease

proto-oncogene

polygenic disease

tumor suppressor gene

Down's syndrome

restriction nuclease

(trisomy 21)

DNA fingerprinting

cancer cell

transfection

carcinoma

transgenic organism

sarcoma

cloned DNA

leukemia

cDNA

lymphoma

knockout organism

tumor

(Answers are given in Appendix A)

1. A base sequence in a portion of one strand of DNA is A-G-T-G-C-A-A-G-T-C-T. Predict:

a. the base sequence in the complementary strand of DNA.

b. The base sequence in RNA transcribed from the sequence shown.

2. The triplet code in DNA for the amino acid histidine is G-T-A. Predict the mRNA codon for this amino acid and the tRNA anticodon.

3. If a protein contains 100 amino acids, how many nucleotides will be present in the gene that codes for this protein?

4. Why do chemical agents that inhibit the polymerization of tubulin (Chapter 3) inhibit cell division?

5. Why are drugs that inhibit the replication of DNA potentially useful in the treatment of cancer? What are some of the limitations of such drugs?

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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