1. CH 11: DNA, RNA, AND PROTEIN SYNTHESIS

2. DNA: The molecule of heredity
The sequence of nucleotides in DNA contain instructions for making proteins.
DNA remains in the nucleus, but in order for it to get its instructions translated into proteins, it must send its message to the cytoplasm.
Proteins are organic compounds composed of a long chain of amino acids.

3. Why are proteins important?
What is a Protein
Proteins are organic compounds composed of a long chain of amino acids.
Why are proteins important?
Hair, horns, nails, skin, muscles
Enzymes-speed up metabolism
Antibodies-fight disease
Hemoglobin-carry oxygen in blood

4. From DNA to Protein
There are two processes involved in converting DNA into proteins:
Transcription-DNA serves as a blueprint for making RiboNucleic Acid or RNA.
Translation-Proteins are made from the instructions on the RNA.

5. Comparing DNA and RNA
RNA contains the sugar ribose; DNA contains deoxyribose.
RNA has ONE strand; DNA has 2 strands.
In RNA, the base Uracil (U) replaces Thymine (T).

6. From DNA to Protein Three types of RNA: Messenger RNA (mRNA)
Transfer RNA (tRNA)
Ribosomal RNA (rRNA)

7. TRANSCRIPTION (Read pg. 206)
One strand of DNA is used as a template to create a strand of mRNA.
RNA nucleotides pair with their complementary DNA nucleotides to make mRNA.
DNA sequence reads T A G C T A A C C
mRNA sequence A U C G A U U G G
mRNA copies and carries the template from DNA (nucleus) to the ribosomes (cytoplasm).

9. Codon-Every set of three nucleotides on mRNA that codes for an amino acid
Each codon specifies one amino acid; more than one codon can specify the same amino acid.

10. Protein Synthesis AT-A-GLANCE

12. Translation (Read pg 208-209)
Converts the message on mRNA into an amino acid chain.
Step 1: Ribosomes composed of rRNA read the mRNA chain
Step 2: tRNA carries (or transfers) the correct amino acid to the mRNA chain.
Amino acid is determined by the mRNA codon.
Step 3: the tRNA anticodon attaches to the mRNA codon by complementary base pairing.
The amino acids link to form a chain
The amino acid chain becomes a protein when it detaches from the ribosome.

13. Translation

15. Translation