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DNA Notes
DNA and Chromosomes
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The _______________________ contains __________________ which are
made of DNA and a segment of ________________ is a ______________.
What does DNA do?
• DNA contains the ___________________.
• The code is the information needed to make ______________________.
DNA Structure
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DNA is a double stranded polymer made of individual nucleotides.
NUCLEOTIDES: The monomer of DNA
• Phosphate group
• Deoxyribose sugar
• Nitrogen base
Nitrogenous Bases
Bases come in two types
– pyrimidines
– cytosine (C)
– thymine (T)
– Uracil (U) found in RNA only
– purines
– guanine (G)
– adenine (A)
The Backbone
• ____________ and _____________ group makes up the
backbone of the DNA molecule
Nitrogenous Bases
• _____________ always pairs with ______________
• _____________ always pairs with ______________
• Always meet in the middle with a week hydrogen bond.
Polarity of DNA
• The polarity of a DNA molecule is opposite;
• the ____ end of one strand matches up to the _____ end of the other
strand. Thus, the strands are said to be "_____________________"
Replication
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______________ of DNA
Occurs in many locations and in both directions
The Procedure
1. _____________ unzips the DNA
2. ______________ – joins individual nucleotides to produce a
new strand.
3. DNA is “proofread” by DNA Polymerase for mistakes.
Protein Synthesis
How are Proteins Synthesized from DNA?
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DNA is ________________ into mRNA (messenger RNA)
mRNA leaves the nucleus and travels to the __________
Ribosomes in the cytoplasm use the code on mRNA to
_____________ it into amino acids
Amino acids form a chain - a ________________.
Transcription
• RNA is very similar to DNA with the following
exceptions:
– _____________________
– it has __________ instead of thymine
– it has the ____________ ribose, instead of deoxyribose
Transcription
• Transcribe the following DNA strand to RNA:
–T G C A T C A G A
– ____ _____ _____
Translation
• The _________ travels through the cytoplasm to the
ribosome.
• The ribosome looks for the "start" _________ - AUG, this is
where the chain begins
• ____________________ has an anticodon at one end and an
amino acid at the other, it binds to a complementary codon.
Draw a tRNA molecule to the right.
• Translate the following mRNA to tRNA:
–ACG UAG UCU
– _____ _____ _____
• Now, what is the amino acid sequence?
What codons mean stop?
After watching the short video clip, summarize protein synthesis.