DNA What do you know about it?

The Secret of Life… Watch the following video and answer the questions about the discovery of DNA!

DNA Extraction Having looked at the card sort try to put the steps in order. Why is each step important?

DNA Extraction 1 – Collect berries as allocated and a pestle and mortar. 2 - Mash the berries using the pestle and mortar. This is to break open some of the cells. 3 – To make an extraction buffer, add 10ml water, 1ml detergent and 1 spatula of salt to a small beaker and stir slowly until the salt dissolves. 4 - Add the extraction buffer to the mashed up berries and mix well using the pestle and mortar.

DNA Extraction 5 – Transfer the mixture to a test tube and incubate at 60 o C for 15 minutes. This starts to break down the cell’s membranes. 6 - Filter the berry mixture through a funnel & filter paper into a clean test tube until it is about 1/3 full. This separates the parts of the cell leaving a liquid containing the berry DNA. 7 – Using a dropper pour the ice cold ethanol slowly down the side of the test tube. The ethanol makes the DNA visible as it is insoluble in ethanol. 8- Use a paperclip to hook the white jelly-like substance forming. This is the DNA!

DNA Genetic information is stored in the nucleus of a cell.

Genetic information is especially found on thread-like structures called, chromosomes. Genes are located on chromosomes in the nucleus.

Genes and chromosomes are made of DNA. DNA stands for Deoxyribonucleic Acid.

DNA has a double helix shape and is made of 4 bases. The 4 bases are shown as; A, C, T and G

Organisms to Bases... Cut out the names and definitions in the cardsort. Arrange the names in order of size – The largest at the top down to the smallest. Then match the definitions to the names.

Genes Genes are sections of DNA containing the instructions needed to make proteins which are made of amino acids.

Decoding… Collect a DNA sequence – this will have a string of letters A, T, G and C to represent the 4 DNA bases. Re-write the DNA sequence leaving a space after every third letter e.g. TACACGACCGTCTAG becomes TAC ACG ACC GTC TAG

Collect a decoder key Use the decoder to find out which amino acid (represented by a different shape for each amino acid) comes first in the sequence e.g. in the sequence above TAC is the first code which in the key means ‘START’ Find the next amino acid in your sequence using the key e.g. ACG is Continue adding the correct amino acids to the chain until the chain is complete. Decoding…

Decoding Posters Make a poster showing your; Starting code - TACACGACCGTCTAG Triplets - TAC ACG ACC GTC TAG Amino acids - Protein – Are any 2 proteins the same? Why?

Why do we need proteins? Enzymes are proteins that help us digest food. Hair is protein. Skin contains protein. Antibodies which fight disease are proteins. Our blood contains proteins.

Questions Where are genes located? Where are chromosomes found? What do genes contain the instructions for making? Give 3 examples of proteins found in your body.

Inheritance Each person’s DNA is unique. This is because they inherit their genes from their parents.

Inheritance Sometimes a change if the order of the code occurs in the genes which are passed on from parents to offspring. This leads to faulty proteins and inherited diseases. Examples include; Cystic Fibrosis and Huntingdon’s Disease.

Questions Why can DNA be used to identify the father or a child? Why can DNA be used to identify criminals? Explain how inherited diseases arise?

Inherited Diseases Task Collect an inherited disorder Case Study card. You have been given a scenario related to a specific disease caused by a problem with the genetic code for a particular gene. Starter sites for research: / / (Huntington’s and cystic fibrosis) or (haemochromotosis) (Tay Sachs)

DNA Structure DNA is double stranded. DNA is a double helix shape. The “rungs” of the ladder of DNA are made of 4 bases, A, C, T, G.

DNA Structure DNA carries the instructions to make proteins. The order of bases determines the order of amino acids. The amino acid sequence determines the type of protein which is made.

DNA Bracelet From the sequence you have been given make a bracelet to show the order of bases which codes for……

DNA Bracelet Use your instructions sheet to make your bracelet. Be careful to use the right colour for each base! Remember A matches T, C matches G!

Edible DNA!! Follow the recipe to make your edible DNA!

Edible DNA!! Using your bracelet and edible DNA explain to your partner the structure of DNA. Tell your partner why the order of the bases is important? What does your sequence code for?

Quick Check What instructions does DNA carry? Where is DNA found in the cell? Where are proteins made in the cell?

DNA to Protein Watch the following video as an introduction to DNA being used to make protein.

DNA to Protein So that the instructions for making protein can pass from the nucleus to the ribosome a new molecule must be made…….. Messenger RNA (mRNA)

DNA to Protein Messenger RNA (mRNA) takes a copy of the code from DNA in the nucleus to the ribosome. At the ribosome amino acids are assembled into a protein as directed by the code.