Download Biology Ch 10 How Proteins are Made

Biology Ch 10 How Proteins
are Made
Section 1 From Genes to Protein
Importance of Proteins
• You are who you are based on your ability to
make specific proteins
• Many diseases are caused by the bodies
inability to make specific proteins properly
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Diabetes
Cystic Fibrosis
Sickle Cell Anemia
Albinism
• The information on how to make those proteins
is stored in the genes (DNA)
From Genes to Proteins
• The genes don’t directly make proteins
– A combined effort between 3 types of RNA
• RNA = ribonucleic acid
– Long chain of nucleotides
– 4 N bases include adenine, guanine, cytosine,
and URACIL
– A-U
G-C
Gene Expression
1. Transcription
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DNA used as a template to form mRNA
mRNA can leave the nucleus
2. Translation
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mRNA message used to create a polymer of
amino acids = protein
tRNA and rRNA work together to deliver the
proper amino acids in the proper order
Transcription
• DNA is unwound and unzipped at the site of the
gene to be expressed (promoter)
• RNA polymerase adds the complementary
nucleotides to the exposed DNA nucleotides
– Every three mRNA bases is called a codon
• Process ends when a stop signal is reached. A
single strand of mRNA can then leave the
nucleus and enter the cytoplasm (ribosome)
A–U
G-C
Translation
• Takes place in the cytoplasm (ribosome)
– rRNA
• Transfer RNA (tRNA) molecules deliver the
proper amino acids to the ribosome
• Each codon codes for a specific amino acid
• tRNA molecules have an anti-codon that
matches the codon
• The delivered AA attaches to the chain adding to
the polymer (protein)
Amino Acid Chart for mRNA