Transcription and Translation How DNA Controls the Cell

DNA and Control of the Cell I. DNA controls the cells by coding for A. Proteins are used 1. in cell construction 2. as enzymes - catalysts that control

II. Protein structure A. Consists of a chain of

    2.  The order of the amino acids in the chain determine the type of that is created 3. Every three base pairs in DNA ( ) codes for one

Transcription Transcription is the process of copying one strand of DNA to

II. RNA is the working molecule A II. RNA is the working molecule A. DNA stays in the so it is protected B. is the copy of DNA that is functional

B. RNA has a Single Strand 1. Only has a single B. RNA has a Single Strand 1. Only has a single *Thymine is replaced by Uracil (Uracil pairs with

Use this DNA template to create a strand of RNA T A C C T A A C G *Divide up your strand into codons

Use this chart to discover what amino acids your codons code for… write them under each codon

Translation  Once the mRNA leaves the nucleus it travels to a ribosome that will help translate the mRNA into an amino acid chain. Where are ribosomes found in the cell? *If the protein is going to be used inside the cell it is made at a *If the protein is going to be packaged for use outside the cell, it will be made on a ribosome attached to the

Translation The ribosome matches up the codons of mRNA with “anitcodons” of transfer RNA (tRNA) by matching up the bases. *Label a codon, anticodon, mRNA, tRNA and amino acid on this image

Translation Each tRNA unit has an amino acid attached to it When two units of tRNA are in the ribosome the amino acids are linked to each other

Translation The ribosome ejects the first tRNA unit and moves down, accepts another tRNA unit and links the amino acids. This continues and the amino acid chain grows.

Translation The ribosome reaches a “stop” codon and the ribosome and protein releases from the mRNA http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/translation.swf

Based on the order of amino acids, the protein folds up into a particular shape that does a particular function in the body: Hemoglobin: delivers oxygen to the body Insulin: regulates blood sugar

Proteins Come in two basic categories: Fibrous: Globular: Fig. 1: Image of a collagen protein responsible for building connective tissue Come in two basic categories: Fibrous: Structure is long chains Function is that they’re typically are a structural protein that help build tissues in the body Globular: Structure is more like a sphere shape Functions are typically enzymes and transport proteins Fig. 2: Representation of a hemoglobin protein responsible for transportation of oxygen in the blood stream