DNA Structure

Essential Questions for Today What is DNA? What is a gene? What is the basic structure of DNA? What is the function of DNA?

What is DNA? (DEOXYRIBONUCLEIC ACID) A Nucleic acid that carries genetic information. A large molecule that contains all of the info to build proteins for a cell.

CHROMOSOME STRUCTURE 1. A chromosome is an enormous strand of super coiled DNA. 2. Sections of DNA on the chromosome that code for proteins are called genes. 3. There are also noncoding sections of DNA (regulatory or unknown function)

What is a GENE? A section of DNA that codes for a specific protein

What are the BUILDING BLOCKS OF DNA? Nucleotides! Nucleotides contain three parts: 1. Sugar 2. Phosphate Group 3. Nitrogen Base (four types, adenine, guanine, thymine and cytosine) What is another molecule that has a PHOSPHATE Group?

What is the STRUCTURE OF DNA? Made of two strands of nucleotides that form a twisted ladder (double helix) Sugar and phosphate alternate along the sides of the ladder (linked by strong covalent bonds) Pairs of nitrogen bases form the rungs of the ladder (linked by weak hydrogen bonds).

What is the STRUCTURE OF DNA? Specific base pairing arrangement: Adenine ALWAYS bonds with Thymine Cytosine ALWAYS bonds with Guanine

4 Nitrogen Bases- Adenine, Guanine, Thymine, Cytosine dk5iS1f0&safety_mode=true&persist_sa fety_mode=1&safe=active

What is the FUNCTION OF DNA? DNA codes for proteins -(structural proteins, enzymes, and hormones) Information for building proteins is carried in the sequence of nitrogen bases proteins determine physical and metabolic traits and regulate growth and development. PROTEINS ARE SO IMPORTANT!

DNA codes for PROTEINS!

SUMMARY What type of organic compound is DNA? What are the building blocks of DNA called? What are the sides of the “Twisted ladder” made of? What are the rungs made of? Which nitrogen bases pair with one another? What is the function of DNA?