This lecture note is specifically designed for medical laboratory technologists, Study notes of Molecular biology

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FOR

Medical Laboratory

Technology Students

Mohammed Awole Adem

Upgraded

Lecture Note Series

Jimma University

MOLECULAR BIOLOGY AND

APPLIED GENETICS

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

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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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INTRODUCTION

Molecular genetics, or molecular biology, is the study of the biochemical mechanisms of inheritance. It is the study of the biochemical nature of the genetic material and its control of phenotype. It is the study of the connection between genotype and phenotype. The connection is a chemical one.

Control of phenotype is one of the two roles of DNA (transcription). You have already been exposed to the concept of the Central Dogma of Molecular Biology, i.e. that the connection between genotype and phenotype is DNA (genotype) to RNA to enzyme to cell chemistry to phenotype.

James Watson and Francis Crick received the 1953 Nobel Prize for their discovery of the structure of the DNA molecule. This is the second most important discovery in the history of biology, ranking just behind that of Charles Darwin. This discovery marked the beginning of an intense study of molecular biology, one that dominates modern biology and that will continue to do so into the foreseeable future..

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The essential characteristic of Molecular Genetics is that gene products are studied through the genes that encode them. This contrasts with a biochemical approach, in which the gene products themselves are purified and their activities studied in vitro.

Genetics tells that a gene product has a role in the process that are studying in vivo, but it doesn’t necessarily tell how direct that role is. Biochemistry, by contrast, tells what a factor can do in vitro, but it doesn’t necessarily mean that it does it in vivo.

The genetic and biochemical approaches tell you different things:

Genetics Æ has a role, but not how direct Biochemistry Æ tells what a protein can do in vitro, but not whether it really does it in vivo

These approaches therefore tell different things. Both are needed and are equally valuable. When one can combine these approaches to figure out what a

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1966 -Gene transcription become reality

1975- Southern blot was invented

1977- DNA sequencing methodology discovered

1981-Genetic diagnosis of sickle cell disease was first shown to be feasible by kan and Chang

1985- PCR develop by Mullis an Co-workers

2001-Draft of Human genome sequence was revealed

Molecular Biology and Applied Genetics

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CHAPTER ONE

THE CELL

Specific learning objectives

⇒ Identify an eukaryotic and prokaryotic cell ⇒ Describe chemical composition of the cell membrane ⇒ List the structure found in a membrane ⇒ Describe the role of each component found in cell membrane

1.0. Eukaryotic and Prokaryotic Cell

► Cells in our world come in two basic types,

prokaryotic and eukaryotic. "Karyose" comes from a Greek word which means "kernel," as in a kernel of grain. In biology, one use this word root to refer to the nucleus of a cell. "Pro" means "before," and "eu" means "true," or "good." ► So "Prokaryotic" means "before a nucleus," and "eukaryotic" means "possessing a true nucleus."