1. Nucleic Acids and Protein Synthesis
Photo credit: Jacob Halaska/Index Stock Imagery, Inc.
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2. Two Types of Nucleic Acids:
1. DNA
2. RNA
Together they have the code to make all necessary proteins = our traits.
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Nucleic Acids: DNA
Deoxyribonucleic Acid
-It is our genetic code
-code for making all proteins/enzymes
= all our traits and cell reactions
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DNA is:
Located:
in the nucleus of all our cells.
Makes up our:
Chromosomes
Number of chromosomes in each of our cells? 46
23 from mom
23 from dad
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Fertilization: 23 23 46 46 46 46 46 46 46
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Chromosomes:
-46 linear pieces/segments of DNA
-Each piece is super coiled into “bow tie” shaped structures during cell division.
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7. Approximately 6ft/cell ~ supercoils into mere nanometers
Supercoiling of DNA: DNA wraps around histone proteins and condenses itself down from 6ft to mere nanometers.
Approximately 6ft/cell ~ supercoils into mere nanometers
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Human Genome:
- Is our complete set of genes that makes up a human.
-there are approximately 22,000 genes in our genome.
-99.9% of every humans genes are identical. There is only a .1% difference in the DNA code from person to person
Karyotype Chart
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9. Male karyotype Female karyotypeXY XX
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Genes:
segments of DNA that codes for 1 or more proteins. Each chromosome is made up of many genes.
Junk DNA
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Every cell in your body has an exact copy of all 46 chromosomes.
BUT cells are selective on what
genes are read and proteins
made.
Ex/ skin makes collagen
pancreas makes insulin
testicles make testosterone
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13. What is the Human Genome Project?
-Research that mapped all 22,000 of our genes.
-Completed in 2003
-Headed by James Watson
We now know exactly where every one of our genes are located.
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Structure of DNA:
1. is a nucleic acid
2. made up of many nucleotides
bonded together to form a large molecule / polymer.
Each nucleotide is made up of:
1. A sugar
“deoxyribose”
2. A phosphate
3. A nitrogen base (4 types)
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16. The Components and Structure of DNA
3. There are four kinds of DNA nitrogen bases:
Adenine
Guanine
Cytosine
Thymine
DNA is made up of nucleotides. Each nucleotide has three parts: a deoxyribose molecule, a phosphate group, and a nitrogenous base. There are four different bases in DNA: adenine, guanine, cytosine, and thymine.
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4. DNA is made up of a double strand of nucleotides held together with weak hydrogen bonds.
5. DNA has a double helix shape (twisted).
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DNA follows the “Base Pairing Rule”
Adenine only bonds to Thymine
Cytosine only bonds to Guanine
Why?
A and T have 2 hydrogen bonds to form and G and C have 3 hydrogen bonds to form
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DNA’s structure
was determined
by James Watson
and Francis Crick
In 1953.
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20. The Components and Structure of DNA
DNA Double Helix
DNA is a double helix in which two strands are wound around each other. Each strand is made up of a chain of nucleotides. The two strands are held together by hydrogen bonds between adenine and thymine and between guanine and cytosine.
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21. Nobel Prize winners in 1962 ~
Crick and Watson
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Watson: current head
of the Human Genome
Project
Crick: died in 2004
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DNA Replication:
-DNA makes an exact copy of itself
-Why?
So cells can divide
and each new cell has an
exact copy of DNA.
-DNA replication occurs in all cells
-Some cells lose the ability to divide.
Example: nerve, brain, heart
-Some cells divide all the time:
Example: skin, bone
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25. -DNA replication requires enzymes.
-Each chromosomes is over 20,000 nitrogen
bases long so it happens in sections.
Interesting but useless bits of knowledge:
DNA is an invisibly thin, very long double strand of nucleotides.
The DNA found in each human cell is almost 2 meters or 6 feet long.
If all the DNA in a human adult were laid end to end the DNA molecule would stretch 113 billion miles.
That would equal 610 trips to the sun and back.
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27. Steps to DNA Replication:
The enzyme DNA helicase unwinds and unzips DNA by breaking the hydrogen bonds between nitrogen base pairs at several places along each strand.
Creating several “replication bubbles”.
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Replication Bubble
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3. Two DNA polymerase enzymes, one on each side of the DNA strand add new nucleotides following the base pair rule.
A to T
G to C
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4. This continues until 2 new but identical DNA molecules are created.
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5. Two new strands recoil into their double helix shape and two new, identical molecules are formed. T A G C A T C G T A G C A T C G
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DNA Replication
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