120 likes | 306 Views
Biology Taktak/Storey 2013. DNA Structure and Function. Review. Recall that there are 4 types of organic compounds: Carbohydrates Proteins Lipids Nucleic Acids. Nucleic Acids. There are 2 types of Nucleic Acids DNA (Deoxyribonucleic Acid)
E N D
Biology Taktak/Storey 2013 DNA Structure and Function
Review • Recall that there are 4 types of organic compounds: • Carbohydrates • Proteins • Lipids • Nucleic Acids
Nucleic Acids • There are 2 types of Nucleic Acids • DNA (Deoxyribonucleic Acid) • RNA (Ribonucleic acid)……more on this to come later!
DNA Functions • DNA controls cells because it contains the CODE that INSTRUCTS the cell to form PROTIENS • Small segments of DNA are known as GENES • Living organisms DIFFER from one another due to the SYNTHESIS of proteins based on the code found in the DNA strands
Different names…. • Recall that DNA will take different forms. • Chromatin- DNA long and thin (INTERPHASE) • Chromosomes- DNA short and thick (MITOSIS)
DNA Discovery • DNA was discovered in 1953 by two scientists: • James Watson and Francis Crick • Rosalind Franklin- took the picture of the structure which gave Watson and Crick the opportunity to develop the model
DNA Structure • Shape of DNA is a DOUBLE HELIX (twisted ladder) • “Sides” or “Backbone” of the DNA is made of alternating DEOXYRIBOSE SUGAR and PHOSPHATE groups.
DNA Structure Continued • “Rungs” of the DNA ladder are paired NITROGEN BASES • Adenine (A) • Thymine (T) • Cytosine (C) • Guanine (G)
Base Pairing Rules • Adenine always pairs with Thymine (A-T) • Guanine always pairs with Cytosine (G-C)
Recall: What is the monomer of a Nucleic Acid??? • The NUCLEOTIDE which contains… • Deoxyribose sugar • Phosphate group • Nitrogen Base (A,T,G,C)
What holds the two strands together? • DNA is held together by HYDROGEN bonds (weak bonds that are broken easily when the DNA code needs accessed or for DNA replication.)