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

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 (10¹²)

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 2Genes

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

DNA Transcription

Translation

Differences between DNA and RNA

DNA RNA

Sugar deoxyribose ribose

Strand Double Single

Bases A,T,C,G A,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 PolymeraseComplimentary bases (A-U) and (G-C)

RNA polymerase Green

DNA strand Blue

RNA Pink

DNA Interactive: Code (copying the code)www.dnai.org

Finding the DNA Structure, Copying, Reading, & Controlling DNA Code

Starting & stopping the RNase

www.DNAi.org Controlling the code

Genetics.utah.edu Epigenetics

Inside the Cell: p.23 RNA’s many talents; p.32 Tags

New Genetics P. 14-16 RNA splicing; p.30-31 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 signalWhen 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?