Cells and DNA

What is a cell?  A cell is the basic unit of structure in a living thing.  Cells are microscopic.  Living things are made up of trillions of cells! Image source: (Plant cell)

What is a cell?  Animal cells are surrounded by a boundary called a membrane. Plant cells have a cell wall.  Inside of cells are small “organelles”. Like our organs, these help the cell function.  Organelles help make energy, remove waste, store liquids…and much more! Image source: (animal cell) Image source: (Plant cell)

The information center…  How does a cell know what types of molecules to make?  The nucleus is inside the cell. This organelle has all the information the cell needs to act.  For example, it “tells” a hair cell how to be a hair cell and not a skin cell. Nucleus Image source: (Plant cell)

Information Storage  The information in the nucleus is stored in molecules called “DNA”.  “Deoxyribonucleic Acid” – this molecule is coiled in a special shape called a double helix Image source:

 DNA uses patterns and sequences to provide information and instructions to the cell.  Your phone number…  Area code: 541 = Oregon,304 = WV  House number: = you!  DNA patterns are made up of four “bases”: A,T,C, and G DNA ATC G Image source:

DNA sequences and Genes  The bases A,T,C,and G pair up on the DNA molecule.  Sequences of base pairs, called genes, provide a “code” for a feature of the organism  AAATTTCGAA = “yellow flowers”

Importance of DNA  The way you, a flower, the cat develops….is due to how your genes are expressed.  Remember: Genes are segments of a long DNA molecule.

One last thing…  Mutations can damage a cell and change how genes are expressed.  This can help or hurt the organism, or be neutral….but, usually it is harmful.  You cannot get superpowers from mutations!