Topic: Genetics Aim: What is DNA? Do Now: Make a K-W-L chart regarding DNA. Fill in the K (what you know) and W (what you want to know) columns.

What is DNA? Deoxyribonucleic acid Makes up genes Stores and passes on genetic information from one generation to the next Discovered by James Watson & Francis Crick in 1962 (Nobel Prize) What is the function of DNA? Who discovered DNA? When? Discovery of DNA was the most important event of the twentieth century. What do chromosomes contain? Genes.

What does DNA look like? A “spiral staircase” called a double helix Double helix (2 strands)

Structure of DNA What is a nucleotide? Building block of DNA Contains a phosphate, sugar, and nitrogen base Two chains of these make up a DNA molecule Nucleotide

DNA Molecule

What are nitrogen bases? Represent the “steps” Four different nitrogen bases in DNA Adenine (A) – Thymine (T) Guanine (G) – Cytosine (C) Adenine (A) always pairs with Thymine (T) Guanine (G) always pairs with Cytosine (C) Example: A ------- T G ------- C T ------- A C ------- G

Draw the complimentary strand of DNA.

Aim: How does DNA replicate? Topic: Genetics Aim: How does DNA replicate? Do Now: A strand of DNA has the bases ATTGCCTAATGCGTA. What would be the sequence of the matching strand of DNA?

Aim: How does DNA replicate? Do Now: Draw and label a nucleotide. Topic: Genetics Aim: How does DNA replicate? Do Now: Draw and label a nucleotide.

How does DNA replicate? Two strand of DNA DNA unzips Free nucleotides match up with the strands Each new DNA has 1 old strand and 1 new strand 3. 1 2.

DNA Replication

Aim: How is DNA organized? Do Now: Explain how DNA is replicated. Topic: Genetics Aim: How is DNA organized? Do Now: Explain how DNA is replicated.

What is a chromosome? Made of DNA Chromosomes are made of many genes joined together like beads on a string Humans have 23 pairs of chromosomes in each body cell with more than 60,000 genes

What determines which genes are on a chromosome? DNA ladder may contain thousands of rungs and nitrogen bases The order of nitrogen bases determines the particular gene on the chromosome The “genetic code” – order of nitrogen bases on the DNA molecule The genetic code (order of nitrogen bases) tells the cell what proteins to make

Topic: Genetics Aim: What is RNA? Do Now: Draw a nucleotide and label all parts? How does a nucleotide relate to DNA?

What is protein synthesis? The cell uses information from a gene on a chromosome to make a specific protein Proteins are made of chains of amino acids Proteins are made in the ribosomes found in cytoplasm Codes for making protein are carried from the nucleus to the ribosomes by RNA Amino Acids

What is RNA? RNA – Ribonucleic acid Only one strand Sugar in RNA = ribose Sugar in DNA = deoxyribose No thymine (T) in RNA, instead it has URACIL (U) example: AGTGCTAAT = DNA strand UCACGAUUA = complimentary RNA strand

What are the types of RNA? Messenger RNA (mRNA): copies code from DNA and brings it out to the ribosome in the cytoplasm Transfer RNA (tRNA): carries amino acids (building blocks of proteins) and adds them to the new growing protein Ribosomal RNA (rRNA): make up ribosomes

Protein Synthesis

Protein Synthesis in Motion http://www.columbia.edu/cu/biology/courses/c2005/images/animtransln.gif

Quiz A – DNA 3 2 What is the name of structure #1? Structures 1, 2, & 3 make up what larger structure? A strand of DNA has the bases GTAATG. What would be the sequence of the complimentary strand of DNA? 1 3 2 BONUS: What is the shape of DNA?

Quiz B – DNA 3 2 What is the name of structure #1? Structures 1, 2, & 3 make up what larger structure? A strand of DNA has the bases GTAATG. What would be the sequence of the complimentary strand of DNA? 1 3 2 BONUS: What is the shape of DNA?

Quiz C – DNA 3 2 What is the name of structure #1? Structures 1, 2, & 3 make up what larger structure? A strand of DNA has the bases GTAATG. What would be the sequence of the complimentary strand of DNA? 1 3 2 BONUS: What is the shape of DNA?

Quiz D – DNA 3 2 What is the name of structure #1? Structures 1, 2, & 3 make up what larger structure? A strand of DNA has the bases GTAATG. What would be the sequence of the complimentary strand of DNA? 1 3 2 BONUS: What is the shape of DNA?

Quiz 7A – DNA 1-4. Draw and label a nucleotide. 5. How does a nucleotide relate to a DNA molecule? What is the shape of DNA? 7-8. What makes up the backbone (sides) of a DNA molecule? A strand of DNA has the bases GTAATG. What would be the sequence of the complimentary strand of DNA? In RNA, Adenine pairs with what nitrogen base?