For this presentation – add to your notes all that is shown in

green font or with green background.

Bristol International Airport =

 

Pilots abort in torrential rain

Microsoft Zune

Frozen to music

How many letters are there in the English language?

How many words are there in the English language?

MAD

• *** had to carry info from one generation to the next• *** heretiable traits had to be distinguishable• *** had to be “copy-able”• How to Extract DNA from Anything Living• Complex, versatile structure ………Deoxyribonucleic

acid.• Describe the model that scientists developed to

display the structure of DNA = twisted ladder, spiral staircase, double helix in which two strands or chains are wound around each other.

• Each strand is made up of nucleotides = a series of molecules (monomers)

• 5-carbon sugar = deoxyribose• 1-phosphate group---------• } nucleic acid (polymer)• 1-nitrogenous base pair---•  • The base pairs are specifically paired as = A/T, C/G• Adenine/Thymine and Guanine/Cytosine

• The base pairs are specifically paired as = A/T, C/G

• Adenine/Thymine and Guanine/Cytosine

• Adenine and guanine are = Purines with two rings in their structure

• Thymine and cytosine are = Pyrimidines with one ring in their structure

• The two strands are held together by (weak) hydrogen bonds between the nitrogenous base pairs.

• 1 human cell > nucleus > chromatin (DNA/histones) > super coiled nucleosomes > 1-2m of DNA 

• Recall from the cell cycle the phase in which replication of DNA takes place = the S phase

• *An enzyme called DNA polymerase controls the replication process and triggers the separation of the hydrogen bonds between the 2 strands. The unzipped base pairs serve as a template and allow new strands to be synthesized. * Complementary

• ATTCGACT ATGCATCACG CTAAGTC

Where do we go from here?

• http://www.tvdsb.on.ca/westmin/science/sbi3a1/Genetics/Replicat.htm

MutationsMutation—mistake in the DNA that causes

errors in protein production.

Point mutation—mistake at a single point in the DNA.

*substitution—different base(s)*insertion—extra base(s)*deletion—lacking base(s)

SubstitutionDNA: ACC GTA CTA ATTmRNA:tRNA:Amino Acid:But is : ACC CTA CTA ATTAmino Acid:

The C has substitutedWhere there should be a G.

Point mutation con’t

Insertion

Should be: AAT TAG CCA GCGBut is : AAT ATA GCC AGC G

An extra base has been inserted where it should notbe causing a frameshift mutation.

What amino acids are formed?

Point mutation con’t

Deletion

Should be: ATA TTA TAG CGA But is: ATT TAT AGC GA

The A from the original strand of DNA is missingcausing a frameshift mutation.

What amino acids are formed?

Point mutation con’t

Chromosomal Mutations

• Deletion—part of a chrosome is missing.

• Duplication—creates extra copies of parts of chromomosomes.

• Inversion—reverse the direction of parts of the chrosomomes.

• Translocation—part of one chrobreaksmosome off and attaches to another.

Significance of Mutations

• Most are neutral (no problem, no benefit)• Some can cause dramatic effect on

proteins created (big problem) (Can I use baby powder instead of flour for my cake?)

• But some may be very beneficial, and provide a source for genetic variability (I substituted chocolate for nuts, and this cake is the best I’ve ever had!)

6th Block…show announcements!!!

http://ghsolycasts.com/announcements/English_Podcasts/English_Podcasts.html

DNA Test Review• Number of sugar molecules in DNA section

containing 3 base pairs.• Name of sugar found in DNA but not RNA.• Carbohydrate subunit of a polysaccharide

polymer. *tough one*

• CONTINUE REVIEWING WITH HOMEWORK…TEST ON friDAY!