Download DNA - Moore Public Schools

DNA
Replication and Protein
Synthesis Review
Lookabaugh Day 4 Review
DNA – Chemical that makes up your chromosomes
• “Deoxyribonucleic Acid”
1. Double stranded Helical
ladder
2. Contains all genetic info
• Blueprint for whole body
3. In the nucleus
4. Made up of nucleotides
• Sugar: Deoxyribose sugar
• Phosphate group
• Nitrogen Bases• Adenine
• Thymine
• Cytosine
• Guanine
DNA Replication- Happens in S phase(Interphase) when
making a new cell Click blue link for Amoeba Sisters video
• Making a copy of DNA
The complementary DNA to the following to
TTG-GCA would be AAC-CGT.
Enzymes cause this UNWINDING and UNZIPPING
Remember make new DNA ALWAYS in 5’ to 3”
direction. What does this mean?
RNA – 3 kinds(mRNA, tRNA and
rRNA) • Ribonucleic Acid
1. Single stranded
2. Made up of
nucleotides
1. Sugar: Ribose
2. Phosphate group
3. Nitrogen Bases1. Adenine
2. Uracil
3. Cytosine
4. Guanine
What is DNA’s JOB?
MAKE PROTEINS for the ORGANISM! SO….uses a process
called
PROTEIN SYNTHESIS
This has 2 MAJOR PARTS
DO YOU REMEMBER WHAT THEY ARE?
***Click on Blue link above and watch the video
Review by the Amoeba Sisters
FIRST: Transcription –(SCRIBBLE down the code)
• DNA  mRNA
• rewriting
DNA is too large and wide to leave
nucleus so a copy is made of just the
section needed (mRNA)
DNA = TAT - CGA so
RNA = AUA - GCU
STEP Two to make a Protein is
“Translation” = decoding bases into language of
1. mRNA leaves nucleus finds a ribosome attached to ER proteins
2. tRNA brings amino acids on tail to pair up with mRNA codon
3. tRNA’s will drop off amino acids and leave after they connect
4. When a STOP codon is
detected on mRNA the
protein(amino acid) strand
will FALL off and get packaged
by ER and Golgi for use where
needed.
Protein Synthesis
• DNA is like the “whole instruction manualBLUEPRINT”.
• RNA is like “the construction workers” reading the
blueprint/instructions and then getting protein built.
Protein Synthesis
mRNA has the 3 letter
CODON which binds to the
3 base letters on
tRNA which has the
ANTICODON.
There are 64 possible letter
combos. Why do we only
have 20 amino acids then?
Mutations
• changes in DNA sequence.
• caused by mutagens: radiation, chemicals or
infectious agents.
• can also occur during replication, transcription or
meiosis.
• benefit mutations are called adaptations.
• If occur in somatic cells (body cells) will not affect
potential offspring.
• If occur in gamete cells (sex cells) can be passed on to
offspring.
Mutations to DNA
• Point mutation – nitrogen base(A,T,C or G)
in DNA sequence replaced with another.
• This may not affect the protein being
made. Because of the WOBBLE EFFECT.
(3rd base)
• Frame shift mutations – nitrogen
base(A,T,C or G) is mistakenly inserted or
deleted from the DNA sequence.
• This almost always affects the protein
being made.
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The diagram below shows models of nucleic acids. A
segment of each model is highlighted.
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14.Based on the model, which
feature is a characteristic of
DNA replication?
A.The molecule makes
chromatin fibers.
B.The molecule is in the
form of a triple helix.
C.Sequence mutations occur
in all DNA strands.
D.Complementary bases
pair together to form new
DNA.
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15.Which of the following would be
produced if a messenger RNA strand is
coded from the DNA sequence
CCCGGAATT?
A. CCCGGAAUU
B. GGGCCTTAA
C. AAATTCCGG
D. GGGCCUUAA
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16.Which amino acid sequence can be coded
from the DNA sequence CAG TAG CGA?
A. Valine –
Isoleucine
– Glycine
B. Valine –
Aspartic
Acid –
Alanine
C. Valine –
Isoleucine
– Alanine
D. Valine –
Phenylala
nine –
Alanine
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