Biology Journal 10/14/2013 What do the letters in the acronym DNA stand for? What 5 elements are found in DNA? Deoxyribonucleic Acid Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous What are the 4 most commonly occurring elements in living things? Carbon, Hydrogen, Oxygen, Nitrogen

1.True or false: DNA and RNA use the same bases: adenine, guanine, cytosine, and thymine. 2.True or false: DNA is antiparallel, which means that the distance between the 2 strands of DNA varies and is not parallel. 3.Name any 2 differences between DNA and RNA Biology Journal 9/30/ Homework Quiz!

Biology Journal 10/1/2014 One of the standards of 2.6 is Draw a simple diagram of the structure of nucleotides of DNA and RNA, using: o circles = phosphates o pentagons = pentoses o rectangles = bases

2.6 Structure of DNA and RNA: The structure of DNA allows efficient storage of genetic information. Nature of science: Using models as representation of the real world—Crick and Watson used model making to discover the structure of DNA. Understandings: The nucleic acids DNA and RNA are polymers of nucleotides. DNA is a double helix made of two antiparallel strands of nucleotides linked by hydrogen bonding between complementary base pairs. The relative lengths of the purine and pyrimidine bases do not need to be recalled, nor the numbers of hydrogen bonds between the base pairs. Applications and skills: Application: Crick and Watson’s elucidation of the structure of DNA using model making. Skill: Drawing simple diagrams of the structure of single nucleotides of DNA and RNA, using: o circles = phosphates o pentagons = pentoses o rectangles = bases Theory of knowledge: The story of the elucidation of the structure of DNA illustrates that cooperation and collaboration among scientists exists alongside competition between research groups. To what extent is research in secret ‘anti-scientific’? What is the relationship between shared and personal knowledge in the natural sciences? Topic 2: Molecular biology (21 hours)

DNAyeeeeeee

What do you call these types of carbohydrates? A DB C Disaccharide MonosaccharidePolysaccharide Review!

What is the name of these carbohydrates? A DB C Dextrose Sucrose RiboseStarch Review!

What are the products of this reaction? H2OH2O + → + Review! What kind of reaction is this? It is a anabolic condensation reaction. Maltose and water. What are the reactants of this reaction? 2 glucose molecules.

The Parts of DNA Deoxyribose: a monosaccharide, or “sugar.” C 5 H 10 O 4.

What is the difference between ribose and deoxyribose? C 5 H 10 O 5 C 5 H 10 O 4 RiboseDeoxyribose Deoxyribose has one less oxygen atom in it than ribose.

The Parts of DNA Phosphate: PO 4 It’s the same phosphate that we find in a phospholipid. What are these?

The Parts of DNA Deoxyribose and phosphate alternate to make up the sugar-phosophate backbone.

The Parts of DNA The bases (aka nitrogenous bases, aka nucleic acids, aka nucleotides) Adenine, cytosine, thymine, guanine They attach to the deoxyriboses

What is a hydrogen bond? Hydrogen bonds are attractions between positive and negative sides of molecules. Review!

 A always pairs with T  C always pairs with G

Complementary base pairing: the size and number of hydrogen bonds of the bases match. How might this help find and correct errors (mutations) in DNA?

DNA Can be represented in many ways…

Which of the following are not found in pairs? Dookies Aces Twins Adenine and Thymine Thymine and Cytosine

Phosphate Deoxyribose Hydrogen bonds A G T C

Where’s the backbone? Where’s the base pairs?

The double helix is a twisted ladder shape that helps the DNA take up less space.

The 2 strands of DNA are antiparallel. This means that the strands are parallel, but have opposite alignments. If DNA were a ladder… The rails of DNA are parallel But, one rail runs “up” and one rail runs “down”

Histones are a protein that the DNA wraps around to take up less space The way that DNA wraps around histones is called the “pearl necklace” shape.

Histones are like little stones that the DNA wraps around. How long would this ball of yarn be if it wasn’t wrapped around something?

Histones are a protein. What is another word for a protein? What are proteins made out of?

A temporary, disposable copy of DNA called RNA is made by the cell whenever it needs to “read” the DNA code to make a protein. How is RNA different? DNA StructureRNA Structure Deoxyribonucleic acid Double stranded Uses thymine (T) Sugar used is deoxyribose (C 5 H 10 O 4 ) Ribonucleic acid Single stranded Uses uracil (U) Sugar used is ribose (C 5 H 10 O 5 )

DNA and RNA comparison

In the 1950s and 60s, the structure of DNA was put hypothesized and verified through sharing evidence between scientists. What are the benefits of free collaboration between scientists? What are the disadvantages of free collaboration between scientists? Left: Watson and Crick. They are often criticized for not giving enough credit to their colleagues for whom they owe many important breakthroughs. Right: A key piece of the puzzle: Rosalind Franklin’s x-ray diffraction picture of DNA.

Your assignment: Show DNA replication using the pieces provided. Show at least 3 base pairs in the “starting DNA” Show at least 2 base pairs in each “new strand of DNA” Label: – Parent strand of DNA and New strands – DNA helicase – DNA polymerase – Hydrogen bonds – Each of the molecules in DNA (deoxyribose, phosphate, cytosine, adenine, guanine, thymine) Define the job of: – DNA helicase – DNA polymerase

Biology Journal 10/15/2013 What are the names of the two most important enzymes in DNA replication? What does each one do? DNA helicase: unzips DNA, making 2 single-strands. DNA Polymerase: adds in new complementary bases (and backbone) to each single strand, making 2 complete copies of DNA.

Biology Journal 10/17/2013 In DNA replication, what do you start with? DNA What do you end with? What is the purpose of replication? 2 sets of the original DNA (through semi- conservative replication) When cells divide, each new cells needs a full set of DNA.