DNA & RNA

What we already know... The nucleus holds the DNA Eukaryotes have linear (in a line) DNA Prokaryotes have circular DNA DNA is copied during Interphase of the Cell Cycle

What you may also know... Traits are distinguishing features or characteristics Traits are passed from parent to offspring Traits are passed on through genes Genes are specific sections of DNA In sexual reproduction, offspring get half their genes from each parent

DNA is INFORMATION DNA = Deoxyribonucleic acid Molecule that stores information Contains instructions for making proteins Similar to a cookbook which contains instructions for making a cake

Check for understanding: What is a trait? When is DNA copied? What is a gene?

Check for understanding: What is a trait? distinguishing features or characteristics When is DNA copied? during Interphase of the Cell Cycle What is a gene? specific sections of DNA

DNA Structure Double Helix -Shaped like a twisted ladder Formed from Nucleotides which are made of: Phosphate Sugar (deoxyribose) Nitrogen base Latin Bonus: Any word in science ending in “-ose” means it is a sugar (ex- glucose, fructose, deoxyribose)

DNA Structure Side rails of ladder are sugar-phosphates Rungs of ladder are formed by 2 nitrogen bases coming together 4 Nitrogen bases (GCAT): Guanine Cytosine Adenine Thymine Let's learn the DNA song! As you listen, write the lyrics in your notes

Base Pair Rule of DNA Structure These Nitrogen Bases ALWAYS pair together! Guanine - Cytosine Adenine - Thymine Let's review!

Check for understanding What are the 3 parts of a nucleotide? What are the 4 bases and how do they pair together?

Check for understanding answers What are the 3 parts of a nucleotide? Sugar, Phosphate, Nitrogen base What are the 4 bases and how do they pair together? Guanine - Cytosine Adenine - Thymine

So what’s RNA? RNA is similar to DNA except RNA has: RNA explained RNA is similar to DNA except RNA has: RIBOSE sugar instead of deoxyribose sugar. URACIL instead of thymine. Has a SINGLE STRAND. Another DNA & RNA song

RNA is needed to make PROTEINS

Try this: Copy this DNA sequence: A - T - G - A - C - G Write the base pair letters of the 2nd strand of DNA. Let's build a DNA molecule on the board!

Check your answer: Copy this DNA sequence: A - T - G - A - C - G Write the base pair letters of the 2nd strand of DNA. T - A - C - T - G - C

History of DNA discovery 1952 Rosalind Franklin takes X-Ray photograph of DNA 1953 James Watson & Francis Crick use Franklin’s images to describe the structure of DNA 1962 Watson, Crick, & Wilkins win Nobel Prize. Franklin died in 1958 so she did not get recognized for her part.