Every cell in a specific organism (body) has the same DNA DNA to RNA to Protein Transcription & Translation

Facts Every body has  200 major types of cells  Total number of cells: trillions (10 ¹²) Each cell contains  10 billion ( billion = 10⁹ ) proteins  2,000+ different varieties of proteins

DNA → RNA → Proteins How is the DNA coded to make proteins? Do all cells produce the same proteins? How do the different cells “know” what proteins to make?  “Gene expression”

The structure of the DNA provides the its function. How does the structure of the DNA provide instructions for the working of the cells?

Biotech course: Overview: Transcription and Translation  Additional information about DNA The Code for Gene Expression  Say it with DNA What controls the code? Proteins  Structure & Function  Enzymes Using biotechnology to produce proteins needed for medicine or products

Video segment

How are proteins made?

DNA Contains Genes DNA Gene 1 Gene 2 Genes

DNA Gene 1 Gene 2 Protein 1 Protein 2 Genes Proteins Genes Provide Instructions for Making Proteins

Proteins Have Functions DNA Gene 1 Gene 2 Protein 1 Protein 2 Genes Proteins Function Blue eye color Blood clotting factor

During replication, each Original strand acts as a template for a new complementary strand

DNA polymerase See HHMI video

Using The New Genetics to help your understanding: Getting the Message Pp. 11 – 14. Transcription RNA splicing  Introns and Exons Pp. 18 – 21 Translation

Gene Expression DNA only carries the instructions, in the form of genes Proteins do the work mRNA

DNATranscription

Translation

Differences between DNA and RNA DNARNA Sugardeoxyriboseribose StrandDoubleSingle BasesA,T,C,GA,C,G,U Function Carries instructions* Intermediary between DNA and proteins * Exception - RNA viruses

A little more about RNA 3 types  mRNA Messenger RNA, works between DNA and protein  tRNA Transfers RNA, converts RNA to amino acids (the smallest part of a protein)  rRNA Ribosomal RNA- part of the ribosome

Differences between DNA and RNA

Transcription DNA is converted to mRNA  Requires protein called RNA Polymerase  Complimentary bases (A-U) and (G-C)

RNA polymerase  Green DNA strand  Blue RNA  Pink

DNA Interactive: Code (copying the code) Finding the DNA Structure, Copying, Reading, & Controlling DNA Code Finding the DNA Structure, Copying, Reading, & Controlling DNA Code

Starting & stopping the RNase  Controlling the code Genetics.utah.edu  Epigenetics Inside the Cell:  p.23 RNA’s many talents; p.32 Tags New Genetics  P RNA splicing; p epigenetics & chromatins

How does it start? DNA contains promoters  Think “promote transcription” Without a promoter RNA polymerase doesn’t know where to start Gene A promoter RNA polymerase

Transcription Once initiated RNA P adds complimentary nucleotides How does it stop?  Stop signal  When RNA P encounters this signal it stops

Eukaryotic Example

Promoter Examples Negative system Repressor prevents transcription If a specific protein is in the cell, then it will bind with the repressor & stop the repressor from working. Then, transcription can take place.

Why is there a negative system to control transcription ?