3.3+DNA+structure

3 Chemistry of Life - 3.1 Chemical elements and water - 3.2 Carbohydrates, proteins and lipids - 3.3 DNA structure - 3.4 DNA replication - 3.5 Transcription and translation - 3.6 Enzymes - 3.7 Cell respiration - 3.8 Photosynthesis - Biochemistry Labs - DNA Labs

3.3 //(and 7.1)// DNA structure
//N.B. This topic links to 7.1 DNA Structure which HL students will be studying in conjunction with this topic. This page contains both Core and AHL content. AHL specific content is written in italics.//


 * Starters**
 * __Discuss the image to the right__ and it's relevance to the topic
 * After the discussion try to identify which assessment statements it is relevant to

source: http://lucasmind.tumblr.com __Learn how to draw a simple diagram of the molecular structure of DNA__. There is lots of good advice in the video, but remember label lines should be drawn with a ruler and avoid arrow heads. media type="custom" key="24526816" Afterwards play the draw label annotate game to test your understanding.


 * Assessment statements** (IBO notes added to some points to clearly indicate what needs to be understood and what does not)
 * 3.3.1 || Outline DNA nucleotide structure in terms of sugar (deoxyribose), base and phosphate. Chemical formulas and the purine/pyrimidine subdivision are not required. ||
 * 3.3.2 || State the names of the four bases in DNA. ||
 * 3.3.3 || Outline how DNA nucleotides are linked together by covalent bonds into a single strand. Only the relative positions are required. ||
 * 3.3.4 || Explain how a DNA double helix is formed using complementary base pairing and hydrogen bonds. ||
 * 3.3.5 || Draw and label a simple diagram of the molecular structure of DNA. ||


 * //7.1.1// || //Describe the structure of DNA, including the antiparallel strands, 3’–5’ linkages and hydrogen bonding between purines and pyrimidines. Major and minor grooves, direction of the “twist”, alternative B and Z forms, and details of the dimensions are not required.// ||
 * //7.1.2// || //Outline the structure of nucleosomes. Limit this to the fact that a nucleosome consists of DNA wrapped around eight histone proteins and held together by another histone protein.// ||
 * //7.1.3// || //State that nucleosomes help to supercoil chromosomes and help to regulate transcription.// ||
 * //7.1.4// || //Distinguish between unique or single-copy genes and highly repetitive sequences in nuclear DNA.// ||
 * //7.1.5// || //State that eukaryotic genes can contain exons and introns.// ||

Log in to the DCS Bridge to obtain your workbooks and supporting resources on [|3.3 Core] and //[|7.1 AHL]// DNA Structure
 * Workbooks and Worksheets **

An alternative set of notes from i-Biology can be found here __Core content only__ media type="custom" key="23828528" __//Core and AHL together//__ media type="custom" key="23828538"

What is DNA (Learn.Genetics) and Zoom in on your Genome (Welcome Trust) provide good introduction to DNA and where it can be found.
 * Presentations and tutorials **

Steven Taylor ( [|i-Biology] ) has a great presentation to view and take notes from before starting your notebook media type="custom" key="23828584"

The khan academy has a good [|introduction to DNA]

Use [|click4biology] to review and complete your notes on [|3.3 DNA Structure] and additionally for //HL students [|7.1 DNA Structure]//

__Display contest__ The class will be divided into groups. Each group will be given an area of wall or board that they can put there work on. The group which comes up with the best display wins a prize!
 * Activities**

Rules and outline for the contest:
 * Displays must **address all the assessment statements**
 * Display must **clearly commnincate** to anyone reading at a distance of 1 metre or more
 * Content is king, but **design** and how clearly the information is communicated **is still very important**

You can in preparation for the display seek help from your teacher ONCE:
 * Help is limited to a **10 minute** Q&A session
 * Your teacher will not volunteer information so **designing relevant questions is important**
 * **Questions have to be specific**, "Can you explain everything about this topic?" is not an acceptable question

Both of the below questions can be examined by research and debate:
 * TOK and useful extras**
 * 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 was Watson and Crick’s “discovery” of the three-dimensional structure of DNA dependent on the use of data generated by Rosalind Franklin, which was shared without her knowledge or consent?
 * //Highly repetitive sequences were once classified as “junk DNA”, showing a degree of confidence that it had no role. This addresses the question: To what extent do the labels and categories used in the pursuit of knowledge affect the knowledge we obtain?//

**Four-stranded ‘quadruple helix’ DNA structure proven to exist in human cells** The work done at Cambridge University opens up possibilities for a new generation of targeted therapies for cancer.
 * Articles for Interest**

[|DNA Anatomy] by John Kyrk has more biochemical detail of DNA structure [|The story of the DNA discovery] is a nice introduction to DNA this youtube link is easy to watch and is only 9 mins long [|Nobelprize.org] outlines the discovery of DNA and why they awarded prizes to Watson, Crick and Wilkins [|Build your own DNA molecule] from the Unversity of Utah gives you practise with base pairing and is a useful introduction to DNA replication
 * Useful Links **