DNA Structure PDF

DNA Structure DNA Structure ⚫ DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix. ⚫ A molecule of DNA is made up of millions of tiny subunits called Nucleotides. ⚫ Each nucleotide consists of: 1. Phosphate group 2. Pentose sugar 3...

DNA Structure DNA Structure ⚫ DNA consists of two molecules that are arranged into a ladder-like structure called a Double Helix. ⚫ A molecule of DNA is made up of millions of tiny subunits called Nucleotides. ⚫ Each nucleotide consists of: 1. Phosphate group 2. Pentose sugar 3. Nitrogenous base Nucleotides Phosphate Nitrogenous Base Pentose Sugar Nucleotides ⚫ The phosphate and sugar form the backbone of the DNA molecule, whereas the bases form the “rungs”. ⚫ There are four types of nitrogenous bases. Nucleotides A T Adenine Thymine C G Cytosine Guanine Nucleotides ⚫ Each base will only bond with one other specific base. ⚫ Adenine (A) Form a base pair. ⚫ Thymine (T) ⚫ Cytosine (C) ⚫ Guanine (G) Form a base pair. DNA Structure ⚫ Because of this complementary base pairing, the order of the bases in one strand determines the order of the bases in the other strand. A T C G T A C G A T G C T A DNA Structure ⚫ To crack the genetic code found in DNA we need to look at the sequence of bases. ⚫ The bases are arranged in triplets called codons. AGG-CTC-AAG-TCC-TAG TCC-GAG-TTC-AGG-ATC DNA Structure ⚫ A gene is a section of DNA that codes for a protein. ⚫ Each unique gene has a unique sequence of bases. ⚫ This unique sequence of bases will code for the production of a unique protein. ⚫ It is these proteins and combination of proteins that give us a unique phenotype (physical appearance).  DNA Gene Protein Trait