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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? - PowerPoint PPT Presentation
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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
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