AP Biology Discussion Notes Monday (or Tuesday) 1/5/2015

WELCOME BACK! You may choose your seat

Semester 2 AP BIOLOGY DNA Structure & Function –DNA replication, Protein synthesis Gene Activity & Biotechnology –(Genetics & Inheritance) Diversity & Organisms Anatomy/Development Ecology –Animal behavior, community & population Ecology

Things to think about: 1.Look over material before the next class –Write down thoughts, connections or questions 2.Read the chapter –even when not “assigned” 3.Watch Videos about topics –even when not assigned 4.Start reviewing topics from last semester –Tie them to topics this semester and write down connections or questions 5.ASK QUESTIONS

PANIC now and avoid the rush!

AP BIO TEST May 11 th

Goals for Today Be able to name the scientists that helped build our knowledge of DNA and be able to describe their contributions Be able to discuss how scientific understanding is built Be able to list or understand the contributions of less known scientists Be name the 3 basic components of DNA

Question of the Day Each day in class I will put up a question of the day. Students will be responsible for writing the question & their best answer. After each student has answered the question on their own we will discuss it as a class QODs will be collected before each test for points!!!

Question of the Day 1/(5) What is DNA? Write your thoughts down, and what you know about it, you don’t have to be sure you are correct!

How long have we known what was the genetic material? (What molecules allow us to inherit similarities and characteristics from our parents?)

3 likely candidates DNA RNA Protein

What do we know about the relationship between DNA & Protein? DNA RNA Protein

Griffith’s Experiments (1928 – publication) Griffith discovered that harmless bacteria could turn virulent when mixed with bacteria that cause disease. A bacteria that is virulent is able to cause disease. Griffith had discovered what is now called transformation, a change in genotype caused when cells take up foreign genetic material.

Oswald Avery’s Experiments (1930 – 1944) Series of experiments showed that the activity of the material responsible for transformation is not affected by protein- destroying enzymes. The activity is stopped, however, by a DNA-destroying enzyme. Thus, almost 100 years after Mendel’s experiments, Oswald Avery and his co-workers demonstrated that DNA is the material responsible for transformation NOT protein.

DNA or Proteins? Even after Avery’s experiments it was not widely accepted that DNA was the genetic material, but this line of research did spark a race of sorts to figure out more about the physical structure of DNA

DNA Nucleotide – a nucleotide is the three component parts together Phosphate Group N Nitrogenous base (Adenine, Guanine, Cytosine, or Thymine) Sugar (deoxyribose)

Erwin Chargaff Chargaff’s research analyzed the amount of each nitrogen base in different organisms Humans Adenine= 30.4% E. coli Adenine = 24.7%

Erwin Chargaff Chargaff’s research determined that in DNA there were always equal parts Adenine = Thymine As well as equal parts Cytosine = Guanine

Erwin Chargaff Chargaff’s research determined that in DNA there were always equal parts Humans Adenine = 30% Humans Thymine = ? Humans Guanine = ? Humans Cytosine = ?

DNA’s Role Revealed In 1952, Alfred Hershey and Martha Chase used the bacteriophage (__________) to prove that DNA carried genetic material. A bacteriophage is a virus that infects bacteria.

Life Cycle of a virus (bacteriophage)

Hershey & Chase use viruses to prove DNA is the genetic material

Still needed to know the structure! What is the structure of DNA? Who discovered the structure of DNA?

DNA is shaped like a double helix (a twisted ladder) This shape was discovered by two scientists: James Watson & Francis Crick

Scientific Knowledge Scientific knowledge and discovery is always built on what we already know, past discovery & knowledge Were Watson & Crick the only ones responsible for discovering the structure of the DNA molecule?

Who is Rosalind Franklin?

Discovery of DNA’s Structure Secret of Photo 51 Video

SPECIES of the Day Poinsettia - Euphorbia pulcherrima

ASSIGNMENT DUE TOMORROW Set 2 goals for the quarter List 3 ways you can help yourself to achieve each goal