Lecture #9 - Gene Expression Ii

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Biology 301 Cellular and Molecular Biology Spring 2002

Lecture # 9: Gene Expression II Translation

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Overall outline  DNA to Protein  RNA Translation  Review of Gene Expression

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

DNA to Protein  The Central Dogma  Flow of information in prokaryotes & eukaryotes  DNA to protein: triplet code  The dictionary of the genetic code

The Central Dogma

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Flow of information in prokaryotes & eukaryotes

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Types of RNA in the eukaryotic cell

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

DNA to protein: triplet code

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

The dictionary of the genetic code • Nirenberg (NIH) & Khorana (MIT) – early 1960s

• UUU -> phenylalanine • Redundancy • no ambiguity • Early evolution

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

RNA Translation  Translation: the basic concept  Structure of tRNA  An aminoacyl-tRNA synthetase joins a

specific amino acid to a tRNA  Anatomy of a ribosome  Initiation of translation  Elongation of translation  Termination of translation  Polyribosomes  Coupled transcription and translation in bacteria

Translation: the basic concept

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Structure of tRNA

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

An aminoacyl-tRNA synthetase joins a specific amino acid to a tRNA

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Anatomy of a ribosome

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Initiation of translation Shine Dalgarno Sequence in mRNA is complementary to a sequence in the rRNA in the small ribosomal subunit

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Translation elongation

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Termination of translation

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Polyribosomes

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Coupled transcription and translation in prokaryotes

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Review of Gene Expression  Summary of transcription & translation in a eukaryotic cell  DNA > RNA > Protein (revisited)

Summary of transcription & translation in a eukaryotic cell

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

Ogan Gurel, MD Biology 301 Lecture # 9 Roosevelt University

DNA > RNA > Protein (revisited)