Monday, November 5th• Warm-up: What are genes?• Review – Nucleic Acid • Replication

• James Watson reflects• Review of DNA model

• Video • Questions from the model

Homework: The New Geneticspp. 11-19Essential Question:How is a protein made from a gene?

Notes/Chunk/questionsSummaery

Warm-up:• All living things do one thing the same way. To make more of itself, it first copies its molecular instruction manual and then passes this information on to its offspring.

• This cycle has been repeated for 3.5 billion years.

• What are genes? What are they made of?

Nucleic Acids Examples

• DNA• DeoxyriboNucleic Acid

• RNA• RiboNucleic Acid

RNA

DNA

Nucleic Acids•Function:

• genetic material• stores information

• Genes (packaged in chromosomes)• blueprint for building proteins

•DNA RNA proteins• transfers information

• blueprint for new cells• blueprint for next generation

proteins

AA

A

A

TC

G

CG

TG

CT

Genes (DNA)are needed to run bodies every day…to make you and me…to make new cells…to make babies!

Nucleic acids• Building block = nucleotides

5 different nucleotides different nitrogen bases A, T, C, G, U

nucleotide – nucleotide – nucleotide – nucleotide

phosphate

sugar N base

Nitrogen basesI’m the A,T,C,G or Upart!

Nucleotide chains• Nucleic acids

• nucleotides chained into a polymer• DNA

• double-sided• double helix• A, C, G, T

• RNA

• single-sided• A, C, G, U

phosphate

sugar N base

phosphate

sugar N base

phosphate

sugar N base

phosphate

sugar N base

strong bonds

RNA

DNA• Double strand twists into a double helix

• weak bonds between nitrogen bases join the 2 strands

• A pairs with T • A :: T

• C pairs with G• C :: G

• the two strands can separate when our cells need to make copies of it

weak bonds

Copying DNA• Replication

• copy DNA• 2 strands of DNA helix are complementary

• they are matching• have one, can build other• have one, can rebuild the whole

• Copying DNA• pairing of the bases allows each

strand to serve as a pattern for a new strand

Newly copied strands of DNA

DNA replication

Watson and Crick 1953 … and others…|

Watson: creating the model• http://www.hhmi.org/biointeractive/media/DNAi_watson_b

asepairing-sm.wmv

Review• Problem 19: The DNA molecule is shaped like a twisted la

dder. :: DNA Learning Center

• http://www.dnalc.org/view/16441-Problem-19-The-DNA-molecule-is-shaped-like-a-twisted-ladder-.html

Biotech Objectives for a DNA model: • Label the functional groups on the sugars and carbons to determine the 5’ and 3’

• Know the components of the DNA “backbone” & where they bond

• Determine the location and function of hydrogen bonds

• Demonstrate that the molecular structure & shape of the complementary pairs is critical• Identify the purine and pyrimidine bases & sizes

• Know the names of the bases (not just letters)

Your model will be similar to this.

DNA Model

Questions about the model• What base does adenine pair with?• What base does guanine pair with?• What is the smallest unit of DNA called?• What is the shape of the DNA model?

DNA Replication • Schematic: HHMI's BioInteractive

- DNA replication (schematic)

• Basic: HHMI's BioInteractive - DNA replication (basic detail)

• Advanced: HHMI's BioInteractive - DNA replication (advanced detail)

• Suppose you know that the sequence of bases on one DNA strand is AGCTCAG. What is the sequence on the opposite strand?

• Referring to the above question, suppose that the 5’-most base on the given strand is the first A from the left to the right. What would the 5’-most base on the opposite strand?

• Assume that a 100 base pair DNA double helix segment contains 45 cytosines. How many adenines are there?

Replication animation• http://www.johnkyrk.com/DNAreplication.html

Video: Understanding DNA