Donations Requested We could use some Gummy Bears (we need lots of these) Red Twizzlers Black Twizzlers Why? Well we are going to be making models of DNA! What is that here we go ***I stand by my promise +10 pts. on a HW assignment if you can find some healthy ingredients from which to make your model!
Genetics The study of heredity whatever that means. Heredity-The passing of traits from parents to progeny (offspring)
DNA 1. It s a nucleic Acid specifically it s Deoxyribonucleic Acid. 2. This is the substance (it s a molecule) that determines inherited characteristics. What s that mean to a human! Inherited means it you get it from mom and dad. A characteristic is something like eye color, the shape of your face your blood type.
The Structure of DNA The DNA molecule looks like a ladder that has been twisted. This shape is called a DOUBLE HELIX. 1950 Irwin Chargaff figures out that there is always the same amount of adenine as thymine, and there was the same amount of cytosine as guanine smart human I gotta say.
The Parts of DNA DNA is made up of NUCLEOTIDES NUCLEOTIDES are made of three parts: 1. A Pentose Sugar: Deoxyribose it s a sugar with 5 carbons (penta=5, -ose=sugar).
2. A Phosphate Group that s a compound with a PO 4- group.
3.One of four different Nitrogenous Bases: Adenine Thymine Cytosine Guanine A T C G
Purines & Pyrimidines aka: Types of Nitrogenous Bases Sooo a nitrogen base can have a single 6 carbon ring is called a PYRIMIDINE: Cytosine and Thymine, or It can have 2 rings and 9 carbons then it s a PURINE (Adenine and Guanine).
Nucleoside: a NITROGEN BASE and a a SUGAR. Nucleotide: a NITROGEN BASE and a PHOSPHATE (PO 4- ). YOU: Waaahhhhh! This is complicated; I don t get it ME: Ohhhh you poor baby. You mean you don t understand the chemistry and biochemical mechanism of the molecule responsible for the existence and diversity of life on Earth after studying it for half an hour? Poor You Welcome to the club of most of us! And DUH! That s why we spend many lifetimes studying this stuff. Now as we were discussing
Nucleoside v Nucleotide What s the big diff?
*Extremely smart dudes/dudettes warning* 1. Rosalind Franklin: used X-ray diffraction to determine that the DNA molecule was a spiral. 2. James Watson & Francis Crick: figured out that the spiral was a double helix (TWO spirals a twisted ladder) and made a model. Let s see you use the properties of high energy electromagnetic waves to discover the shape of an organic macromolecule yeah that s what I thought.
The Structure of the Double Helix The Rails of the ladder are alternating molecules of sugars and phosphates. The Rungs of the ladder are the nitrogen (nitrogenous) bases that are attached to the sugars.
Here s What it Looks Like
Here s Where it Fits in With Cells and YOU!
Here s Another View
Genes are A GENE is a set of chemical instructions for assembling a protein. DNA is the molecule that carries these genetic instructions. Within a gene, each group of three nitrogenous bases codes for one amino acid. A sequence of amino acids is linked to make a protein. Proteins are fundamental to the function of cells and the expression of traits.
Here s The Relationship To Chromosomes
Replication When DNA copies (every time a cell divides), it splits down the middle separating in between the base pairs. The new strand of bases is complimentary that means that where there s an A (adenine), there will be a T (thymine) to match with it. Where there is a C (cytosine), there will be a G (guanine) to match with it. Write the complimentary strand for this sequence: GAATTCGCGGAT
Here s What You Should Have GAATTCGCGGAT CTTAAGCGCCTA
Enzymes (an enzyme is a protein look for the ase) *There are a number of enzymes that are involved in this process: DNA helicase: unzips the DNA DNA polymerase: lines up the new bases DNA ligase: glues sections together *Bonus info no extra charge, and no you don t need to know it. But some day
Genetic Engineering By understanding DNA we can you tell me it s in your book We re gotta get waaaay more into this part when we hit GENETICS which is gonna be soon!