AP Biology Discussion Notes

Thursday 01/08/2015

Goals for Today• Be able to say what the central dogma of

biology is.

• Be able to describe the structure of DNA and its associated terms

• Be able to describe the process of DNA replication

• Be able to “build” a strand of DNA

Question of the Day 1/8

• List the 2 groups of Nitrogen bases and which bases belong to each group (Hint we are not talking about pairing.)

*Bases always pair Pyrimidine to _________

Review of Base Pairing

Ever Heard the Word “DOGMA”?

dog⋅ma• 1.a system of principles or tenets, as

of a church.• 2.a specific tenet or doctrine

authoritatively laid down, as by a church

• 3.prescribed doctrine: political dogma.

• 4.a settled or established opinion, belief, or principle.

The Central Dogma

Genetic information is:

Encoded in DNA;Transmitted by DNA Replication;

Transcribed into RNA;Translated into Protein.

A Nucleotide

DNA Structure

Deoxyribose—

A pentose sugar

O

2’C

1’C

5’C

4’C

3’C

Ribose vs DeoxyriboseRNA vs DNA

Ribose vs Deoxyribose• How will adding an oxygen affect things?

Ribose vs Deoxyribose• What does it matter?

DNA Coiling—A Nucleosome• DNA itself is negatively charge. WHY?• So, what charge do histones have???• DNA

• Histone Proteins

What is the sugar (S)

in DNA?

What is “P”?

Hydrogen bonds:

Strong or Weak?

Covalent bonds:

Strong or Weak?

ANTIparallel?

Antiparallel?

Antiparallel!The strands are parallel, but run in opposite directions!

Antiparallel!

Antiparallel!

The Famous Double Helix

DNA Replication

DNA Replication is known as

“Semiconservative Replication”

Semi = ???

Conserve = ???

“The Players”in DNA Replication

• The Enzymes– Helicase (“Hacks”)– DNA Polymerase (“Pastes”)– Ligase (“Links”)

• Nucleotides (A,T,C,G)• Origin(s) of Replication• Leading Strand• Lagging Strand• 5’ 3’• Okazaki Fragments

• DNA Replication in Action

Let’s Build SOME!?

Secret of Photo 51Thoughts & Questions?• Time to reflect maybe on how we

“other people”• Are there people that you don’t treat

well?• What do you do when people around

you are not acting respectfully?

Species of the Day 1/8• Rough-legged Hawk

– Buteo lagopus

Species of the Day 1/8

Species of the Day 1/8• Rough-legged Hawk

– Buteo lagopus

If the egg cell of this hawk had 30 chromosomes, how many chromosomes would you find in its SOMATIC cells?