Download DNA, RNA and Proteins

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Mendel showed
that traits are
passed from parent
to offspring.
Genetics:
Instructions for
how genes are
inherited.
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Genes are made up of segments of DNA:
Deoxyribonucleic acid.
DNA is the primary material that causes
recognizable, inheritable characteristics in
related groups of organisms.
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DNA is composed of four nucleotide
subunits:
◦ Each nucleotide has the same five carbon sugar
molecule and phosphate group but different
nitrogenous bases:
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Adenine
Guanine
Cytosine
Thymine
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Winding stair case – 1
Parts of the nucleotide
subunits – 2
1’s find another 1 and
compare notes!
2’s find another 2 and
compare notes!
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If you are a 1 find a 2
If you are a 2 find a 1
Share your information but
DO NOT COPY!!!
You must explain it to your
partner!!!
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Pyrimidines: Thymine and Cytosine (T&C)
Purines: Adenine and Guanine (G&A)
DNA is in the shape of a spiral stair case/
double helix of two complementary strands
of nucleotides.
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A always binds with T
G always binds with C
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So A=T and G=C
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Purine always binds to
pyrimidine
Watson, Franklin and
Crick discovered 3D
model .
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A=T
G=C
Base pair
rule
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Read and summarize Watson and Cricks model of
DNA.
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K,W,L
◦ Knew
◦ Would like to learn more about
◦ Learned
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Draw, label and explain a strand of DNA
including the nucleotide subunits, base
pairing and complementarity of the strands.
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1.
2.
3.
DNA replication: the process of making a
copy of DNA. (synthesis in the cell cycle)
In DNA replication, the DNA molecule
unwinds, and the two sides split.
Then new nucleotides are added to each
side until two identical sequences result.
DNA replication occurs before a cell divides
so that each cell has a complete copy of
DNA.
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DNA replication McGraw Hill
http://highered.mcgrawhill.com/olcweb/cgi/pluginpop.cgi?it=swf::53
5::535::/sites/dl/free/0072437316/120076/
micro04.swf::DNA%20Replication%20Fork
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The double helix
unwinds.
Complementary
strands of DNA
separate from each
other and form Y
shapes areas are called
replication forks.
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At the replication fork, new nucleotides are
added to each side according to the base
pairing rules.
The original two strands serve as a template
for two new strands.
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DNA replication produces two identical DNA
molecules
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During the replication of DNA, many proteins
form a machinelike complex of moving parts.
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DNA helicases unwind the DNA double helix
during DNA replication.
This process causes the helix to unwind and
forms a replication fork.
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Proteins called DNA polymerases catalyze the
formation of the DNA molecule.
The polymerases add nucleotides that pair with
each base to form two new double helixes.
DNA polymerases also have a “proofreading”
function.
During DNA replication, errors sometimes occur,
and the wrong nucleotide is added to the new
strand. DNA polymerase cannot add another
nucleotide unless the previous nucleotide is
correctly paired.
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In prokaryotic cells, replication starts at a
single site. In eukaryotic cells, replication
starts at many sites along the chromosome.
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Prokaryotic cells usually have a single DNA
molecule, or chromosomes. Prokaryotic
chromosomes are a closed loop, may contain
protein, and are attached to the inner cell
membrane.
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While prokaryotes have a single
chromosome/loop, eukaryotic cells often
have several chromosomes.
By starting DNA replication at many sites
along the chromosome they can replicate
their DNA faster than prokaryotes, two
distinct replication forks form at each start
site, and replication occurs in opposite
directions.
Eukaryote
Both
Chromosomes
Replication fork
Several
Faster
Bigger
pro
Closed loop (1)
1 closed loop
Slower
Smaller
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Create a comic strip explaining DNA
replication of a eukaryotic organism using all
proteins and correct terminology.
You need three steps including these words
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Rep fork
DNA helicase
DNA polymerase
Template strand
New strand
Base pair rule
nucleotide
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Proteins perform most of the functions of
cells. DNA provides the original “recipe”.
RNA: ribonucleic acid allows genetic
information to be taken from DNA and
proteins be made.
Gene expression: the manifestation of genes
into specific traits (geno determines pheno)
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The first stage of gene expression.
RNA is making proteins from the information
found in DNA.
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1. DNA
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2. RNA
3. Protein
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Second stage of gene expression.
Information form RNA is used to make
specific proteins.
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In cells three types of RNA complement DNA
and translate the genetic code into proteins.
RNA vs. DNA
RNA
Both
DNA
Uracil
four bases
Thymine
one strand of
nucleotides
carry genetic
information
two strands of
nucleotides
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1 – messenger RNA
2 – transfer RNA
3 – ribosomal RNA
1 share with other 1’s
Then 1, 2, 3
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Messenger RNA:
carries instructions
for a gene to the site
of translation.
Transfer RNA: reads
the messenger mRNA
sequence.
Ribosomal RNA:
found in ribosomes,
transports proteins
from the ER as they
are produced.
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During transcription , the information in a
specific region of DNA (a gene) is transcribed, or
copied into RNA.
Step 1: RNA polymerase binds to the promoter ( a
specific DNA sequence/start location).
Step 2: RNA polymerase unwinds the dbl helix to
expose both paired nucleotide bases.
Step 3: RNA polymerase links and binds
complementary base units to each strand of DNA.
The result once the stop codon is reached is one
strand of mRNA is produced.
Transcription
Both
Replication
mRNA is made,
using portions of
each strand of
DNA
use DNA as a
template.
DNAis made,
using both entire
strands of DNA
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Translation occurs in a sequence of steps,
involves three kinds of RNA and results in a
complete polypeptide.
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Each 3 nucleotide sequence is called a codon.
Each codon unit codes for a specific amino
acid.
Turn to in the book and look at the amino
acids that are possible there are 20.
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Transcribe and then translate this sequence:
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ATCGGCGGGATTTATTCCCG
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Transcribe and then translate this sequence:
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ATC GGC GGG ATT TAT TCC CG
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Now use the codon chart to determine which
amino acids this codes for.
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The relationship of gene expression is
complex.
Despite the neatness of the genetic code,
every gene cannot be simply linked to a
single outcome.
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Complete the handout by transcribing and
translating the sequence to produce a protein