Download LN #22

LN #22
DNA to Protein
California Content Standards
Genetics
4a. Students know the general pathway by which ribosomes synthesize
proteins, using tRNAs to translate genetic information in mRNA.
4b. Students know how to apply the genetic coding rules to predict the
sequence of amino acids from a sequence of codons in RNA.
DNA
Full Name
Sugar
# of strands
Nitrogen bases
Types
Location
RNA
Full Name
Sugar
# of strands
Nitrogen bases
Types
Location
DNA
Deoxyribonucleic
acid
RNA
Ribonucleic acid
Full Name
DNA
Deoxyribonucleic
acid
Sugar
Deoxyribose
# of strands
Nitrogen bases
Types
Location
RNA
Ribonucleic acid
Ribose
Full Name
DNA
Deoxyribonucleic
acid
Sugar
Deoxyribose
# of strands 2
Nitrogen bases
Types
Location
RNA
Ribonucleic acid
Ribose
1
Full Name
DNA
Deoxyribonucleic
acid
Sugar
Deoxyribose
# of strands 2
Nitrogen bases Adenine (A)
Types
Location
RNA
Ribonucleic acid
Ribose
1
Guanine (G)
Cytosine (C)
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Uracil (U)
Full Name
DNA
Deoxyribonucleic
acid
Sugar
Deoxyribose
# of strands 2
Nitrogen bases Adenine (A)
Types
Location
RNA
Ribonucleic acid
Ribose
1
Guanine (G)
Cytosine (C)
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Uracil (U)
One type
DNA
Three types
mRNA, tRNA,
rRNA
Full Name
DNA
Deoxyribonucleic
acid
Sugar
Deoxyribose
# of strands 2
Nitrogen bases Adenine (A)
RNA
Ribonucleic acid
Ribose
1
Guanine (G)
Cytosine (C)
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Uracil (U)
Types
One type
DNA
Three types
mRNA, tRNA,
rRNA
Location
Nucleus
Nucleus &
cytoplasm
In the Nucleus
• Transcription
– occurs in the nucleus
– a portion of DNA is transcribed
(copied) into mRNA.
– mRNA is made by applying
base pairing rules.
• messenger RNA (mRNA)
– carries the instructions for
making proteins to the
cytoplasm.
– mRNA has codons.
– a codon is a set of 3 bases that
codes for an amino acid. there
are a total of 20 amino acids
that make up proteins.
In the Cytoplasm
• Ribosome
– made of protein and
ribosomal RNA (rRNA)
– site where proteins are
made.
– mRNA attaches to the
ribosome in order for
protein synthesis to
occur.
Also found in the Cytoplasm
• Transfer RNA (tRNA)
– vehicle that brings the
correct amino acid
according to the
directions on mRNA.
– tRNA has a site that
holds an amino acid
and a site that bonds
with mRNA.
– the anticodon on tRNA
bonds with the codon
on mRNA.
Translation
1. tRNA carrying an amino acid
bonds to the mRNA.
2. a bond is formed between the
amino acids.
3. the mRNA slides across the
ribosome. the tRNA without an
amino acids leaves the ribosome
4. tRNA carrying an amino acid
bonds to the mRNA.
End of Translation
• Translation continues
until a stop codon is
reached.
• When the stop codon
is reached a releasing
factor bond to the
mRNA and the protein
is released.
Steps for making proteins
DNA strand
transcription
mRNA
translation
Phe
Gly
Arg
Phe
Protein
(amino acid chain)
Summary
• What are the differences between DNA
and RNA?
• What are the steps for making proteins?
• Where in the cell do transcription and
translation occur?
• What is made during transcription?
• What happens during translation?