The Structure and Function of DNA

The Function of DNA Genes are made of DNA DNA contains the blueprint for producing the whole organism Three critical things genes need to do: 1.) genes need to carry information from one generation to the next 2.) put that information to work by determining the heritable characteristics of organisms 3.) genes need to be easily copied

Structure Scientists James Watson and Francis Crick developed a three dimensional model of DNA This model of DNA consisted of two strands which were wound around each other like a twisted ladder. This structure is known as a double helix

Components DNA is a long molecule made up of units called nucleotides Each nucleotide is made up of three basic components: 5-carbon sugar called deoxyribose Phosphate group Nitrogenous base

Nitrogenous Bases There are four kinds of nitrogenous basses in DNA: Adenine Guanine Cytosine Thymine Provide the code for making proteins

The backbone of DNA chain is formed by sugar and phosphate groups of each nucleotide. Nitrogenous bases stick out sideways from the chain The nucleotides can be joined together in any order

The Opposite Strand The opposite strand of nucleotides matches the other strand in a particular pattern. Adenine = Thymine Cytosine = Guanine

Left Hand Assignment: DNA Structure Glue the DNA strand and use the following instructions to color the double helix. Write and answer the questions when you are finished DNA Structure Analysis The twisted ladder structure of DNA is called a ________________. The backbone of DNA is made up of _______________________. The ladder-like rungs of DNA are made up of _________________. Adenine always pairs up with __________. Cytosine always pairs up with _________________. A nucleotide is the basic building block of DNA. A nucleotide is made up of one ___________, one ________, and one___________. DNA Coloring Instructions Color the deoxyribose sugars green. Leave the phosphate groups white. Color the nitrogen base adenine orange. Color the nitrogen base thymine light blue. Color the nitrogen base cytosine red. Color the nitrogen base guanine yellow.