Molecular Biology and Applied Genetics

529 Pages·2010·1.61 MB·English

MOLECULAR BIOLOGY AND
APPLIED GENETICS

FOR

Medical Laboratory
Technology Students

Upgraded

Lecture Note Series

Mohammed Awole Adem

Jimma University
MOLECULAR BIOLOGY AND
APPLIED GENETICS

For

Medical Laboratory
Technician Students

Lecture Note Series

Mohammed Awole Adem

Upgraded - 2006

In collaboration with
The Carter Center (EPHTI) and The Federal
Democratic Republic of Ethiopia Ministry of
Education and Ministry of Health

Jimma University
PREFACE

The problem faced today in the learning and teaching of
Applied Genetics and Molecular Biology for laboratory
technologists in universities, colleges andhealth
institutions primarily from the unavailability of textbooks
that focus on the needs of Ethiopian students.

This lecture note has been prepared with the primary
aim of alleviating the problems encountered in the
teaching of Medical Applied Genetics and Molecular
Biology course and in minimizing discrepancies
prevailing among the different teaching and training
health institutions. It can also be used in teaching any
introductory course on medical Applied Genetics and
Molecular Biology and as a reference material.

This lecture note is specifically designed for medical
laboratory technologists, and includes only those areas
of molecular cell biology and Applied Genetics relevant
to degree-level understanding of modern laboratory
technology. Since genetics is prerequisite course to
molecular biology, the lecture note starts with Genetics
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followed by Molecular Biology. It provides students with
molecular background to enable them to understand
and critically analyze recent advances in laboratory
sciences.

Finally, it contains a glossary, which summarizes
important terminologies used in the text. Each chapter
begins by specific learning objectives and at the end of
each chapter review questions are also included.

We welcoming the reviewers and users input regarding
this edition so that future editions will be better.

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ACKNOWLEDGEMENTS

I would like to acknowledge The Carter Center for its
initiative, financial, material and logistic supports for the
preparation of this teaching material. We are indebted to
The Jimma University that support directly or indirectly
for the visibility of this lecture note preparation.

I extend our appreciation to the reviewers of the
manuscript during intra-workshop, Namely, Ato
Tsehayneh Kelemu , Biochemistry Department, School
of Medicine, and Ato Yared Alemu, School of Medical
Laboratory Technology, Jimma University.We greatly
appreciate them for their attitude, concern and
dedication.

I also acknowledge all reviewers of the manuscript
during inter-institutional workshop and those who
participated as national reviewers.

Last but not least I would like to acknowledge tyhose
who helped me directly or indirectly.
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TABLE OF CONTENTS

Preface............................................................................ i
Acknowledgement.............................................................. iii
Table of Contents............................................................... iv
List of Figures ................................................................... xi
General objectives............................................................. xiv

CHAPTER ONE: THE CELL
1.0. Eukaryotic and Prokaryotic Cell .......................... 1
1.1. Function of the cell .............................................. 5
1.2. The chemical components of Cell membranes... 8
1.3. Membrane structure............................................. 10

CHAPTER TWO: THE CELL CYCLE
2.0. Introduction.......................................................... 13
2.1. Control of the Cell Cycle...................................... 15
2.2. Steps in the cycle................................................. 16
2.3. Meiosis and the Cell Cycle................................... 18
2.4. Quality Control of the Cell Cycle.......................... 18
2.5. Regulation of the Cell Cycle................................. 19
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2.6. Mitosis.................................................................. 23
2.7. Meiosis................................................................. 30
2.8. Comparison of Meiosis and Mitosis..................... 33
2.9. Meiotic errors....................................................... 33
2.10. Mitosis, Meiosis, and Ploidy............................... 34
2.11. Meiosis and Genetic Recombination.................. 35
2.12. Meiosis and Sexual Reproduction...................... 38

CHAPTER THREE: MACROMOLECULES
3.0. Introduction.......................................................... 40
3.1. Carbohydrate....................................................... 41
3.2. Nucleic acids ....................................................... 43
3.3. Protein................................................................. 46
3.4. Helix..................................................................... 49
3.5. Tertiary structure.................................................. 58
3.6. Macromolecular Interactions................................ 63
3.7. Denaturation........................................................ 64
3.8. Renaturation........................................................ 69

CHAPTER FOUR: GENETICS
4.1. Mendelian genetics.............................................. 73
4.2. Mendel's first law: principle of segregation.......... 79
4.3. Mendel's second law: principle of independent assortment.. 80
4.4. Mendel's third law: principle of Dominance.......... 81
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4.5. Exception to Mendelian Genetics........................ 82

CHAPTER FIVE: CHROMOSOME STRUCTURE AND FUNCTION
5.1. Chromosome Morphology.................................... 96
5.2. Normal Chromosome........................................... 97
5.3. Chromosome Abnormalities................................. 100
5.4. Types of Chromatin ............................................. 105
5.5. Codominant alleles.............................................. 106
5.6. Incomplete dominance......................................... 107
5.7. Multiple alleles..................................................... 108
5.8. Epistasis............................................................... 108
5.9. Environment and Gene Expression .................... 109
5.10. Polygenic Inheritance ........................................ 110
5.11. Pleiotropy .......................................................... 112
5.12. Human Chromosome Abnormalities ................. 113
5.13. Cytogenetics...................................................... 119

CHAPTER SIX: LINKAGE
6.0. Introduction.......................................................... 125
6.1. Mapping............................................................... 128
6.2. Double Crossovers.............................................. 132
6.3. Interference.......................................................... 132
6.4. Deriving Linkage Distance and Gene Order from
Three-Point Crosses ........................................... 134
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CHAPTER SEVEN: PEDIGREE ANALYSIS
7.1. Symbols Used to Draw Pedigrees....................... 145
7.2. Modes of inheritance............................................ 147
7.3. Autosomal dominant............................................ 150
7.4. Autosomal recessive............................................ 151
7.5. Mitochondrial inheritance..................................... 157
7.6. Uniparental disomy.............................................. 158

CHAPTER EIGHT: NUCLEIC ACID STRUCTURE AND FUNCTION
8.0. Introduction.......................................................... 161
8.1. Deoxyribonucleic acid.......................................... 162
8.2. Ribonucleic acid................................................... 167
8.3. Chemical differences between DNA & RNA........ 170
8.4. DNA Replication................................................... 173
8.5. Control of Replication........................................... 191
8.6. DNA Ligation........................................................ 193

CHAPTER NINE:DNA DAMAGE AND REPAIR
9.0. Introduction.......................................................... 200
9.1. Agents that Damage DNA ................................... 201
9.2. Types of DNA damage......................................... 202
9.3. Repairing Damaged Bases.................................. 203
9.4. Repairing Strand Breaks...................................... 209
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9.5. Mutation............................................................... 210
9.6. Insertions and Deletions...................................... 214
9. 7. Duplications........................................................ 216
9.8. Translocations...................................................... 219
9.9. Frequency of Mutations ...................................... 220
9.10.Measuring Mutation Rate.................................... 223

CHAPTER TEN: GENE TRANSFER IN BACTERIA
10.0. Introduction........................................................ 226
10.1. Conjugation........................................................ 227
10.2. Transduction...................................................... 232
10.3. Transformation................................................... 238
10.4. Transposition..................................................... 241
10.5. Recombination................................................... 242
10.6. Plasmid.............................................................. 243

CHAPTER ELEVEN: TRANSCRIPTION AND TRANSLATION
11.0. Introduction ....................................................... 247
11.1. Transcription...................................................... 249
11.2. Translation......................................................... 252
11.3. Triplet Code....................................................... 254
11.4. Transfer RNA..................................................... 258
11.5. Function of Ribosome ....................................... 261
11.5. The Central Dogma............................................ 261
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