Download Honors Biology Module 7 Cellular Reproduction

Honors Biology
Module 7
Cellular Reproduction and DNA
November 12, 2015
Notebook Check Today
Through Module 6
OYO’s
Study Guide
Module Tests completed and graded
Lab book completed
Class Challenge
Draw a picture of an animal
By Bev
Doolittle
Part 1: What are you Thankful for this year?
Part 2: How many different pies can you
write down in 1 minute?
Fluid Mosaic Model
Quiz
Fluid Mosaic Model
Answer A- K
Extra Credit: 1 and 2
Fluid Mosaic Model
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
Integral Protein – Protein Molecule - globerprotein
Hydrophobic Tail
Glycoprotein
Hydropholic head – glycerol – gylcolipid – lipid
molecule
Peripheral Protein – glycoprotein
Phospholipid Bilayer
Glycolipid
Glycoprotein
* Cholesterol
Carbohydrate
Protein Channel – Transport Protein
Cellular Reproduction and DNA
All living organisms reproduce. It is one of the
four criteria for life.
Scientists have tried to understand how an
organism’s offspring receive the traits and
characteristics that make then what they are.
Sometimes the offspring and the parents look
identical and other times you can hardly believe
the offspring came from those parents.
The beginning of a real explanation for how
traits are passed on from generation to
generation was developed by a monk
named Gregor Mendel in the mid 1800’s.
He did careful experiments with peas,
determining how pea plants reproduce and
passed on characteristics to their
offspring.
Hidden Away
Unfortunately, this magnificent work was
tucked away in a monastery for more than
50 years! When it was finally discovered,
it laid the groundwork for all of our modern
studies of genetics.
Genetics: The science that studies how
characteristics get passed from parent to
offspring.
Building on the work of Gregor Mendel,
Scientists today have determined that
each organism contains a storehouse of
information that governs its traits and
characteristics.
This storehouse is DNA and its main
function is to tell the cell what proteins to
make.
It may be hard to believe, but most of your
traits and characteristics are governed by
what kinds of proteins your cells make.
Eye color is completely dependent upon
what proteins are produces in some of the
cells in your eyes. The coding for the
production of certain proteins in your eyes,
your DNA determines your eye color.
Inherent Limit set up by your DNA
Not all of your traits are characteristics are
completely determined by your genetic makeup.
If you lift weights and workout, you will develop
strong muscles. Even though you increase your
strength, there is a fundamental limit to how
strong you can become. Your DNA determines
the general range of how strong your muscle
can become.
Genetic Tendency
It turns out that the majority of characteristics
in your body are determined in this way.
The DNA sets a range of possibilities.
You might have heard that Alcoholism is genetic.
This is partially true. A Swedish study looked at
alcohol use in 3000 children who were adopted
and raised by nonrelatives. The incident of
alcoholism was 2 1/2 times higher among those
children who had at least one biological parent
who was an alcoholic.
What the data indicates is that DNA might set up
an tendency towards or away from alcoholism,
but that people can break that tendency.
DNA
Your DNA alone does not determine who you are
or what you will become.
There are some traits (blood type, for example)
that are completely determined by your DNA.
However for many characteristics, your DNA just
sets up a general framework. Within that
general framework, what you do with yourself
will ultimately decide what you become.
3 Factors
There are 3 factors that determine what kind
of person you will be:
1. Genetic factors: The general guideline
of traits determined by a person’s DNA.
2. Environmental factors: Those
“nonbiological” factors that are involved
in a persons surroundings such as the
nature of the person’s parents, friends
and your individual behavior choices.
“Free Will”
Proverbs 23:7
“For as he thinks in his heart, so is he.”
3. Spiritual Factors: The factors in a
person’s life that are determined by the
quality of his or her relationship with
God.
2 Corinthians 5:17 (NKJV)
“Therefore, if anyone is in Christ, he is a new
creation; old things have passed away;
behold, all things have become new.”
This means that anyone who belongs to Christ
has become a new person. The old life is
gone; a new life has begun!
These three factors work together to
determine what kind of person you are.
From a Christian point of view, spiritual
factors are of the utmost importance for
life, health and peace.
DNA is split up into little groups known as
Genes.
Gene: A section of DNA that codes for the
production of a protein or a portion of
protein, thereby causing a trait.
Your Genetic traits or tendencies are
determined by what proteins are produced
in your cells. A gene is actually coding for
a particular genetic trait or tendency.
In our second hour we will perform
Experiment 7.1 DNA Extraction and
hopefully actually see DNA strands.
Experiment 7.1
DNA Extraction
OBJECT: To extract DNA from peas so that
you can see what DNA looks like on a
macroscopic scale.
OYO Question 7.1
Page 198
Transcription
In multicellular organisms, specific cells have specific
tasks which they must accomplish so that the
organism will survive.
In your body, you have skin cells that shield the inside
of your body from contaminants. You have cells in
your retina of your eye that detect light and sent
electronic messages to your brain based on the light
that they detect.
How do these cells perform such radically different
tasks?
Simply, they produce different types of
proteins. The tasks that a cell can
complete are dependent on the proteins
that it produces.
Before you see how a cell uses DNA to
produce protein, you need to understand
an important chemical of life, Ribonucleic
Acid (RNA) .
RNA
Is made up of nucleotides, but the individual
structure of the nucleotides is a bit
different.
The sugar that makes up the foundation of
nucleotides is ribose, not deoxyribose (as
in the case of DNA).
RNA
Unlike DNA, they do not form a double helix.
1. RNA forms a single strand of joined
nucleotides.
2. RNA has four nucleotides bases.
3. 3 of the RNA strands are like DNA’s
(adenine, cytosine, and guanine), one of
them is different (uracil).
Uracil performs the same tasks in RNA that
thymine does in DNA.
RNA has uracil in place of thymine.
Don’t be confused… When you are thinking about
RNA, just remember that uracil takes the place
of thymine. DNA is much more stable than RNA
because DNA uses thymine and deoxyrobose
instead of uracil and ribose.
This means it is unlikely to undergo major
changes with time, making it the ideal
molecule for storing information from
generation to generation, so that each
organism reproduces after its own kind.
(Genesis 1:11)
RNA has a lot of similarities to DNA, but also
some differences.
Why is it important in the process of how the
cell makes proteins? RNA acts like a
camera.
The main portion of a cell’s DNA is in its
nucleus, but proteins are made in the
ribosomes which are outside of the nucleus.
To get information from the nuclear DNA to
the ribosomes, one type of RNA makes a
“snapshot” of the DNA and takes that
information out of the nucleus to the
ribosome.
How is that Done?
Certain nucleotide bases can only link to other nucleotide
bases. RNA has nucleotide bases. It has cytosine,
guanine, and adenine, just like DNA. But RNA also has
Uracil.
The RNA can link its nucleotide bases to the bases on the
DNA.
1. The uracil in RNA links up to the adenine in
DNA.
2. So the then the Adenine in the RNA can link to the
thymine in DNA,
3. the cytosine in RNA can link to the Guanine in DNA,
and
4. the guanine in RNA can link to the cytosine in DNA.
What does all this accomplish?
When RNA does its job, it produces a “negative” of
the DNA section that it is copying.
Everywhere the DNA has a cytosine, the RNA will
have a guanine.
Everywhere DNA has a guanine, the RNA has a
cytosine.
Everywhere the DNA has a thymine, the RNA will
have an adenine
Everywhere DNA has adenine, the RNA will have a
uracil.
This is much like what happens when film is
being developed. During the developing
process, the first thing to appear is a
negative.
The negative is dark everywhere that the
picture is supposed to be light, and it is
light everywhere that the picture is
supposed to be dark. Based on this
negative, then a picture can be made.
Dr. Wile’s animation CD
Transcription: Figure 7.1
Based on the “negative” produced by RNA,
a protein can be made.
When the RNA strand is built, it is a negative
image of the DNA strand to which it linked.
This process is called transcription, and
the negative image produced by
transcription can be used by the ribosome
to make a protein.
Translation
After transcription, the RNA leaves the
nucleus and moves to the ribosome. This
carries the negative image of the gene that
was transcribed to the organelle that
produces the protein. Because the RNA
that performs transcription is essentially a
messenger (sending instructions from the
nuclear DNA to the ribosome), we call this
a Messenger RNA (mRNA).
In order to get the DNA’s instructions from the
nucleus to the ribosome, the RNA produces a
negative image of the DNA;s nucleotide
sequence and takes it to the ribosome.
The ribosome is surrounded by amino acids,
enzymes, and a different kind of RNA called
transfer RNA (tRNA). Transfer RNA is a big
molecule that contains a special sequence of
three necleotides called Anticodon (a threenucleotide base sequence on tRNA)
Translation: Figure 7.2
A strand of mRNA can be thought of as a bunch of
three-nucleotide sequence. Each threenucleotide base sequence is called a codon. A
strand of tRNA contains a three-nucleotide base
seque4nce called an anticodon. A certain
anticodon on tRNA results in an certan amino
acid boded to the tRNA. Since the tRNA
anticodons are attracted by the mRNA codons,
the net result is that a codon on mRNA attracts a
specific amino acid.
Translation Explained
When the tRNA strands have linked up to the
mRNA, there are amino acids lined right up next
to each other.
So what is a protein?
It is a bunch of amino acids linked together in a
particular sequence.
This happens again and again, so that many,
many amino acids link up together. When all the
amino acids called for by the codons on mRNA
are linked together, the result is a protein.
When a cell needs to make a protein, its DNA has the plan
for making that protein in a long series of threenucleotide base sequences.
Messenger RNA reads this sequence and makes a
“negative image” of the relevant portion of DNA.
It then takes this series of nucleotide base sequences out
to the ribosome.
Once at the ribosome, each codon (set of three nucleotide
bases) on the mRNA will attract a particular anticodon
(set to three nucleotide bases) on tRNA.
The tRNA that is attracted to the codon has a particular
amino acid riding on it. This amino acid is determined by
the anticodon on the tRNA.
Since each codon on mRNA attracts a particular anticodon,
the condons attract a particular amino acid.
As the amino acids line up, they link together, forming a
protein.
Transcription and Translation
This process we just went over is split into
two phases:
1. Transcription
2. Translation
Transcription
mRNA makes its negative image in order to
copy the nucleotide sequence in DNA.
This is like a transcriptionist “copying” a
conversation by writing everything down.
Translation
The mRNA leaves the nucleus and goes to the
ribosome, where the tRNA strands carry amino
acids to the mRNA and line them up in the order
determined by the sequence of nucleotides.
The amino acids then bond together, making a
protein.
The “language” of the nucleotide base sequences
in RNA is translated into the “language” of amino
acid sequences in a protein.
transcription
translation
DNA -----
RNA
-----
See figure 7.3
Protein
For Further Explanation
Mr. Anderson’s Youtube
Mendelian Genetics
http://youtu.be/NWqgZUnJdAY
What is DNA?
http://youtu.be/q6PP-C4udkA
Transcription and Translation
http://youtu.be/h3b9ArupXZg
DNA Replication
http://youtu.be/FBmO_rmXxIw
Mitosis and Meiosis Simulation
http://youtu.be/zGVBAHAsjJM
Mitosis
http://youtu.be/1cVZBV9tD-A
Phases of Mitosis
https://youtu.be/mXVoTj06zwg
Synchronized Swimming Mitosis
https://youtu.be/eFuCE22agyM
Onion root tip
http://youtu.be/mUBlZ1VNReQ