Download DNA NB Pages 19 and 20

DNA STRUCTURE AND REPLICATION
PAGE 19
DNA Notes Day 2
Warm Up
What is the base pairing rule?_____________________________________________________
How DNA is Copied
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DNA is double stranded – base pairing allows for easy copying; one strand serves as a
______________ for a new strand
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____________________– the process of making a new DNA strand
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DNA double helix is __________________by an enzyme called a ________________.
Helicase breaks ___________________ bonds linking the nitrogen bases
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The point where the helix separates is called the ______________ ___________.
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At the fork; enzymes called DNA polymerase moves along the strands, reading the nitrogen
base of each nucleotide, and adds the ______________________ nucleotide to the new strand
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DNA polymerase will ___________________ – it will only add a new nucleotide if the
previous one was added correctly following the base pair rules
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______________________ occurs in many places within the strand. It does not start at one end
and end at the other; but occurs in segments
DNA STRUCTURE AND REPLICATION
Steps for Replication
1. DNA ________________ unzips the DNA by breaking the hydrogen bonds holding the bases
together
2. The two strands unwind creating a __________________ __________.
3. Each strand serves as a _____________ so the correct pair can come in and bind to the strands
4. DNA polymerase joins the nucleotides together and _____________ the new strand.
Proofreading improves the odds of not having _______________ in the DNA
5. Two _________________ DNA molecules are made
The Path of Genetic Information
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Cells turn the information found within the ____________ on DNA into a set of instructions
for use in building ________________.
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This set of instructions of the gene is called ribonucleic acid or _________.
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RNA is a____________ strand of nucleotides; DNA is ____________ stranded
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The sugar in RNA is a 5 Carbon sugar called ____________; DNA’s sugar is deoxyribose
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RNA does not contain _____________, but has replaced Thymine with the base __________
DNA compared to RNA
How many
strands?
Nucleotide
subunit
Phosphate
Group
DNA
RNA
2
1
Deoxyribose
Sugar
Nitro
-gen
Base
phate
Nitro
-gen
Base
Ribose
Sugar
Group
Deoxyribose sugar
Bases
Phos-
Thymine (T)
Adenine (A)
Guanine (G)
Cytosine (C)
T–A
G–C
Ribose sugar
Uracil (U)
Adenine (A)
Guanine (G)
Cytosine (C)
U–A
G–C
DNA STRUCTURE AND REPLICATION
There are 3 forms of RNA
1.
2.
3.
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PAGE 20
mRNA = messenger RNA
tRNA = transfer RNA
rRNA = ribosomal RNA
All 3 RNA’s are responsible for processing the information in a gene into ___________, this
process is
GENE EXPRESSION
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Gene expression occurs in 2 stages.
1. Transcription (RNA is made)
2. Translation (protein is made)
Transcription: Making RNA
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•
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__________________ takes place inside the ________________
____________ is made in the form of mRNA.
It has a U (uracil) instead of T (thymine)
– _____________________________
Three Types of RNA
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_______________ – used as a blueprint or template for a protein; carries DNA’s information
to site of translation
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______________ – decodes mRNA into amino acid sequences
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______________ – RNA part of a ribosomes structure.
The Genetic Code
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Instructions on _________ are written as a series of __________ nucleotide sequences called a
_____________.
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Each ______________ (every three nucleotides) corresponds to a certain
______________________ or a stop signal
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_______possible codon combinations
Translation: Making Proteins
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Takes place in the _______________
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_____________ carries the code so that proteins can be made.
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_____________ translates that code and turns it into protein.
DNA STRUCTURE AND REPLICATION
Genes and Proteins
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_____________ contain nothing more than the instructions for assembling proteins
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______________ are the keys to almost everything that living cells do
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Many proteins are enzymes which catalyze and regulate chemical reactions
Examples of enzymes determining characteristics
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An ______________produces the ________________ that makes a flower red
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An enzyme produces an ____________ on your red blood cells determining your
_____________________
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Enzymes control the growth, shape, and size of your cells
MEDIA CLIP QUESTIONS
1. Your chromosomes are in which organelle? _____________________________
2. Chromosomes contain long coils of what?
_________________
3. How long would DNA from ONE cell stretch? _______________________
4. The four building blocks pair as follows: ___ with ___ and ___ with ___
5. What kind of polymerase copies the information in a gene? ________________
6. The DNA always stays where? ______________________________
7. What then, takes the genetic information out of the nucleus? ___________________
8. What reads mRNA to make it into a protein? ___________________________
9. What molecule translates DNA and RNA into protein? ____________________
10. What do proteins do? _____________________________________________________