Topic: GeneticsTopic: Genetics

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

What is DNA?What is DNA?

• DDeoxyriboeoxyribonnucleic ucleic aacidcid• Makes up genesMakes up genes• Stores and passes on genetic Stores and passes on genetic

information from one generation to the information from one generation to the nextnext

• Discovered by James Watson & Francis Discovered by James Watson & Francis Crick in 1962 (Nobel Prize)Crick in 1962 (Nobel Prize)

What does DNA look like?What does DNA look like?

• A “spiral staircase” called a A “spiral staircase” called a double double helixhelix

• Double helix (2 strands)Double helix (2 strands)

Structure of DNAStructure of DNAWhat is a nucleotide?What is a nucleotide?

• Building block of DNABuilding block of DNA• Contains a phosphate, sugar, and Contains a phosphate, sugar, and

nitrogen basenitrogen base• Two chains of these make up a DNA Two chains of these make up a DNA

moleculemolecule

Nucleotide

DNA MoleculeDNA Molecule

What are nitrogen bases?What are nitrogen bases?

• Represent the “steps”Represent the “steps”• Four different nitrogen bases in DNAFour different nitrogen bases in DNA

– Adenine (A)Adenine (A) – Thymine (T)– Thymine (T)– Guanine (G) Guanine (G) – Cytosine (C)– Cytosine (C)

• Adenine (A) always pairs with Thymine (T)Adenine (A) always pairs with Thymine (T)• Guanine (G) always pairs with Cytosine Guanine (G) always pairs with Cytosine

(C)(C)• Example:Example:

A ------- TA ------- T G ------- CG ------- C

T ------- AT ------- A C ------- GC ------- G

Draw the complimentary strand of Draw the complimentary strand of DNA. DNA.

Topic: GeneticsTopic: Genetics

AimAim: How does DNA replicate?: How does DNA replicate?

Do NowDo Now: A strand of DNA has the bases : A strand of DNA has the bases ATTGCCTAATGCGTA. What would be the ATTGCCTAATGCGTA. What would be the

sequence of the matching strand of sequence of the matching strand of DNA?DNA?

Topic: GeneticsTopic: Genetics

AimAim: How does DNA replicate?: How does DNA replicate?

Do NowDo Now: Draw and label a nucleotide.: Draw and label a nucleotide.

How does DNA replicate?How does DNA replicate?• Two strand of DNATwo strand of DNA

1.1. DNA unzipsDNA unzips

2.2. Free nucleotides match up with the Free nucleotides match up with the strandsstrands

3.3. Each new DNA has 1 old strand and 1 Each new DNA has 1 old strand and 1 new strandnew strand

3.

2.

1

DNA ReplicationDNA Replication

Topic: GeneticsTopic: Genetics

AimAim: How is DNA organized?: How is DNA organized?Do NowDo Now: Explain how DNA is : Explain how DNA is

replicated.replicated.

What is a chromosome?What is a chromosome?• Made of DNA Made of DNA • Chromosomes are made of many genes Chromosomes are made of many genes

joined together like beads on a stringjoined together like beads on a string• Humans have 23 pairs of chromosomes in Humans have 23 pairs of chromosomes in

each body cell with more than 60,000 geneseach body cell with more than 60,000 genes

What determines which genes What determines which genes are on a chromosome?are on a chromosome?

• DNA ladder may contain thousands of DNA ladder may contain thousands of rungs and nitrogen basesrungs and nitrogen bases

• The order of nitrogen bases determines The order of nitrogen bases determines the particular gene on the chromosomethe particular gene on the chromosome

• The “The “genetic codegenetic code” – order of nitrogen ” – order of nitrogen bases on the DNA moleculebases on the DNA molecule

• The genetic code (order of nitrogen bases) tells the cell what proteins to make

Topic: GeneticsTopic: Genetics

AimAim: What is RNA?: What is RNA?Do NowDo Now: Draw a nucleotide and label all : Draw a nucleotide and label all parts? How does a nucleotide relate to parts? How does a nucleotide relate to

DNA?DNA?

What is protein synthesis?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 Amino AcidsAcids

What is RNA?What is RNA?• RNA – RNA – RRiboibonnucleic ucleic aacidcid• Only one strandOnly one strand• Sugar in RNA = riboseSugar in RNA = ribose• Sugar in DNA = deoxyribose Sugar in DNA = deoxyribose • No thymine (T) in RNA, instead it has No thymine (T) in RNA, instead it has

URACIL (U)URACIL (U)

exampleexample: :

AGTGCTAAT = DNA strandAGTGCTAAT = DNA strand

UCACGAUUA = complimentary RNA UCACGAUUA = complimentary RNA strandstrand

What are the types of RNA?What are the types of RNA?

1.1. Messenger RNA (mRNA):Messenger RNA (mRNA): copies code copies code from DNA and brings it out to the from DNA and brings it out to the ribosome in the cytoplasmribosome in the cytoplasm

2.2. Transfer RNA (tRNA):Transfer RNA (tRNA): carries amino carries amino acids (building blocks of proteins) and acids (building blocks of proteins) and adds them to the new growing proteinadds them to the new growing protein

3.3. Ribosomal RNA (rRNA):Ribosomal RNA (rRNA): make up make up ribosomesribosomes

Protein SynthesisProtein Synthesis

Protein Synthesis in MotionProtein Synthesis in Motion

http://www.columbia.edu/cu/biology/courses/c2005/images/animtransln.gif

Quiz A – DNAQuiz A – DNA1. What is the name of

structure #1?2. What is the name of

structure #2?3. What is the name of

structure #3?4. Structures 1, 2, & 3

make up what larger structure?

5.5. A strand of DNA has the A strand of DNA has the bases GTAATG. What bases GTAATG. What would be the sequence would be the sequence of the complimentary of the complimentary strand of DNA?strand of DNA?

BONUSBONUS: What is : What is the shape of the shape of DNA?DNA?

11

22

33

Quiz B – DNAQuiz B – DNA1. What is the name of

structure #1?2. What is the name of

structure #2?3. What is the name of

structure #3?4. Structures 1, 2, & 3

make up what larger structure?

5.5. A strand of DNA has the A strand of DNA has the bases GTAATG. What bases GTAATG. What would be the sequence would be the sequence of the complimentary of the complimentary strand of DNA?strand of DNA?

BONUSBONUS: What is : What is the shape of the shape of DNA?DNA?

11

22

33

Quiz C – DNAQuiz C – DNA1. What is the name of

structure #1?2. What is the name of

structure #2?3. What is the name of

structure #3?4. Structures 1, 2, & 3

make up what larger structure?

5.5. A strand of DNA has the A strand of DNA has the bases GTAATG. What bases GTAATG. What would be the sequence would be the sequence of the complimentary of the complimentary strand of DNA?strand of DNA?

BONUSBONUS: What is : What is the shape of the shape of DNA?DNA?

11

22

33

Quiz D – DNAQuiz D – DNA1. What is the name of

structure #1?2. What is the name of

structure #2?3. What is the name of

structure #3?4. Structures 1, 2, & 3

make up what larger structure?

5.5. A strand of DNA has the A strand of DNA has the bases GTAATG. What bases GTAATG. What would be the sequence would be the sequence of the complimentary of the complimentary strand of DNA?strand of DNA?

BONUSBONUS: What is : What is the shape of the shape of DNA?DNA?

11

22

33

Quiz 7A – DNAQuiz 7A – DNA

1-4. Draw and label a nucleotide.

5. How does a nucleotide relate to a DNA molecule?

6.6. What is the shape What is the shape of DNA? of DNA?

7-8. What makes up 7-8. What makes up the backbone the backbone (sides) of a DNA (sides) of a DNA molecule?molecule?

9.9. A strand of DNA has A strand of DNA has the bases GTAATG. the bases GTAATG. What would be the What would be the sequence of the sequence of the complimentary complimentary strand of DNA?strand of DNA?

10.10. In RNA, Adenine In RNA, Adenine

pairs with what pairs with what

nitrogen base?nitrogen base?