Your “Do Now” 2/23(On ½ sheet of paper)

What is DNA replication?

What has to happen to DNA before it can be replicated?

What is the name of the chemicals that “unzip” it?

What can happen if DNA is not copied perfectly?  

Where does a mutation have to happen if it gets passed on to somebody’s kids?

http://www.youtube.com/watch?v=zdDkiRw1PdU&feature=related

http://www.pbs.org/wgbh/aso/tryit/dna/#

Agenda 2/24 Notes #3 Practice probs (partners) Get Candy Lab & DNA Replication

Activity in Final day for Test Retakes Progress reports home today Phone calls home this afternoon

Learning Target

I can explain the process of protein synthesis and how proteins determine our traits

CH 12 Notes #3 Protein Synthesis

Protein Synthesis:

Process of making proteins from a DNA template

We need proteins for:1) Traits2) Cell Structure3) Hormones 4) chemical reactions

Some basics: RNA

RNA = Ribonucleic acid Single stranded Can leave nucleus to go into cytoplasm RNA uses A, C, G, and Uracil (U)

There are 3 types of RNA:

Messenger RNA (mRNA) Makes copies of DNA inside nucleus

Transfer RNA (tRNA) Brings amino acids to

ribosomes during translation

There are 2 major parts to protein synthesis

A. Transcription

B. Translation

Part A: Transcription

Making an RNA template from the DNA

Step 1: Unzip the DNA

Step 2: mRNA attaches to DNA template

Similar to DNA replication

Base-paringBUT: RNA uses U’s instead of T’s

Step 3: mRNA moves out of the nucleus & into the cytoplasm

Important: DNA stays in the nucleus!

Let’s try some DNA TRANSCRIPTION

A G A T A C C C T G A CU C U A U G G G A C U G

DNA Sequence:

mRNA Sequence:

Part B: Translation

The process of using mRNA to make proteins

Proteins are made up of long strands of chemicals called amino acids

Part B: Translation

Step 1: mRNA moves to a ribosome

Step 2: the ribosome “reads” mRNA nucleotides 3 at a time

Each set of 3 nucleotides is called a codon

Step 3: tRNA brings an amino acid (AA) to connect to mRNA Each tRNA has an set of three bases that

match-up to the mRNA’s codons called anti-codons

ExamplemRNA codon: U C CtRNA Anti-codon: A G G

Reading the mRNA code to build proteins

Practice: UAG = _____________

GGG = _______________ AAC = ____________

Step 4: Creating a Protein

Amino acids are connected by peptide bonds to form a protein

Example: AAG = Phenylalanine

DNA translation must be accurate

Amino acids must be in the correct order to build the right protein

If mutations in the DNA happen, the wrong protein will be made

http://www.pbs.org/wgbh/aso/tryit/dna/#

Overview of Protein Synthesis

DNA

RNA

Protein

Transcription

Translation

http://www.youtube.com/watch?v=erOP76_qLWA&feature=related

Practice Problem

DNA sequence: ATA GCC UAA What is the mRNA strand?

UAU CGG AUU What is the amino acid chain?

What is the amino acid chain?UAU CGG AUU