Download DNA – The Double Helix

DNA – The Double Helix
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Recall the nucleus is often called the
“control center” because it controls all
of the cell’s activities. (eg. Cellular
reproduction)
Chromosomes
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Are threadlike structures in the nucleus,
made of DNA
DNA
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Deoxyribose nucleic acid
The nucleic acid that stores and transmits
the genetic information from one
generation of an organism to the next; it
carries the genetic code
Genetic code = the program of the cell
which is passed on from one generation to
the next
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DNA controls the production of proteins
within the cell; which proteins are made is
determined by the sequence of the DNA.
Proteins are the building blocks of an
organism. How you look is largely
determined by the proteins that are made.
Proteins make up skin hair and even parts
of individual cells.
Structure of DNA

formed of units called nucleotides it is
the shape of a double helix (spiralling
ladder)
Nucleotide

Each nucleotide contains three basic
parts:
A 5-carbon sugar (deoxyribose)
 Phosphate group
 Nitrogenous base
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Nitrogenous bases
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There are only 4 types of nitrogenous
bases in DNA:
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Adenine
Guanine
Cytosine
Thymine
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DNA contains millions of bases
Complimentary Base pairing
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The force that
holds two strands
of the DNA double
helix together
through hydrogen
bonds