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Review Chapter 10
Nucleic Acids and Protein Synthesis
Characteristics of DNA
 Made up of nucleotides (deoxyribose (sugar), phosphate, nitrogen base)
 Four type of bases (A,T,C,G)
 Double strand of DNA in the shape of a double helix
 Used to carry the genetic information
Base pairing in DNA
 A=T
 C=G
Steps in DNA replication
1. DNA unwinds
2. Helicase is used to separate the strands and form the replication fork
3. DNA polymerase is used to add new chains of DNA using complementary
nucleotides
4. Two copies of the DNA are made with one old strand and one new strand
(Write-out steps)
Characteristics of RNA
 Single strand
 Made up of ribose (sugar), phosphate, nitrogen bases
 Nitrogen bases ( A = U and C = G)
 Made from DNA and carries genetic information into the cytoplasm
Three different types of RNA and their function
 Messenger RNA (mRNA): single strand shape that carries the genetic information from
the nucleus to the cytoplasm

Transfer RNA (tRNA): hairpin shape that carries a specific amino acid to the ribosome
and has an anticodon

Ribosomal RNA (rRNA): globular shape that is a part of the ribosome where the protein
will be made
Steps in transcription: process of making RNA from DNA
1. RNA polymerase binds to promoters
2. DNA strands are separated
3. RNA polymerase adds complementary RNA nucleotides using one DNA strand
as template
4. Continues until termination signal is reached
Codons and the genetic code
 3 bases read together to form a “word”
 the “word” indicates a specific amino acid
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Steps in translation: process of making a protein
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mRNA moves to the ribosome and attaches
tRNA brings in the first amino acid and links to the mRNA
second tRNA brings in the next amino acid and links to the mRNA
peptide bond forms between the two amino acids
first tRNA is released from the ribosome
third tRNA brings in the next amino acid
stop codon is reached
mRNA is released from the ribosome and the protein is complete
(Put steps in correct order, don’t have to write out steps)
Define
Mutation: change in DNA sequence
Replication: coping DNA
Transcription: making RNA from DNA
Translation: making a protein from RNA
Codon: group of 3 bases on mRNA
Anticodon: group of 3 bases on tRNA
Protein: made of a sequence of amino acids and put together in the ribosome
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