Class Summary - Today we started discussing movement of substances across a membrane. We talked about the passive forms of movement including facilitated diffusion, diffusion and osmosis. These types of movement move across a concentration gradient (from high concentration to low concentration) so they do not require energy. However, active methods of movement including active transport and endocytosis and exocytosis require energy in order to perform. We looked at gummy bears in hypotonic solutions (gummy bears grew) and hypertonic solutions (gummy bears shrunk) and isotonic solutions which made gummy bears stay the same. Today we reviewed DNA structure. We talked about DNA containing the genetic structure for every cell in our body. We get half of our genetic information from our mom and half from our dad. DNA shape is a double helix. The 'handles' of the double helix are sugar (deoxyribose) and a phosphate group. The rungs of the double helix are the nitrogenous bases (adenine, thymine, guanine and cytosine). Adenine always pairs with Thymine and Guanine always pairs with Cytosine. A 'nucleotide' would consist of a nitrogenous base and a sugar and a phosphate. Nucleotides are held together by hydrogen bonds. The order combination of the nitrogenous bases will indicate which amino acid it is, and in turn which protein is indicated. Three nitrogenous bases is an amino acid. Proteins can range from a few amino acids to many. Then students were to start creating strands of DNA in model form.
Homework - Cell Projects are due on Friday
Objectives - Students will recognize different affects of movements across a plasma membrane. Students will label and list structure of DNA.