DNA Structure

http://www.youtube.com/watch?v=8kK2zwjR V0M 0:00-5:07

DNA Has Three Primary Functions: Storage of genetic information DNA is a stored record of precise instructions. Self-duplication and inheritance DNA is capable of making copies of itself and passing those copies on. Expression of genetic message The code in DNA can be TRANSLATED to produce specific materials in the cell.

DNA Structure The structure of DNA is like a twisted ladder Known as a double-helix

Structure DNA is a type of molecule known as nucleic acid. All nucleic acids are composed of nucleotides. Five-carbon sugar (deoxyribose) Phosphate group Nitrogen Base

Put a box around a single nucleotide.

Nitrogen bases The “rungs” of the DNA ladder, are one of four bases. -Adenine (A) -Thymine (T) -Guanine (G) -Cytosine (C) The order of these bases determine the genetic code.

Base pairing The two DNA strands are held together by hydrogen bonds, which are relatively easy to break when DNA needs to replicate

Base Pairing A’s always pair with T’s A’s and T’s C’s always pair with G’s C’s and G’s Always

Base Pairing and DNA Replication If you know the sequence of one strand… what do you know about the other? T G A C G G A C T G C C One strand can be used as a template to make a new strand

DNA Organization NUCLEOTIDE BASE-PAIR (2 Nucleotides) DNA GENE (Segment of DNA) CHROMOSOME

Chromosomes Humans have 46chromosomes One molecule of DNA= one chrosomome

Summarizing the Big Ideas 1.Read through your notes 2. Draw a 2 strand, DNA Double Helix and include: 6 Nucleotides on each side(Phosphate, 5 Carbon Sugar, Nitrogen Base) 6 correct Base Pairs 3. Write out the Correct Complementary Strand of Nucleic Acids- ACTGCGATGCTTAGGCTA