CH7 key concepts genetic material: DNA DNA structure DNA replication
DNA
description
Transcript of DNA
![Page 1: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/1.jpg)
DNA
What do you know about it?
![Page 2: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/2.jpg)
The Secret of Life…Watch the following video and answer the questions about the discovery of DNA!
![Page 3: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/3.jpg)
DNA Extraction
• Having looked at the card sort try to put the steps in order.
• Why is each step important?
![Page 4: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/4.jpg)
DNA Extraction1 – 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.
![Page 5: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/5.jpg)
DNA Extraction5 – Transfer the mixture to a test tube and incubate at 60oC 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!
![Page 6: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/6.jpg)
DNA
Genetic information is stored in the nucleus of a cell.
![Page 7: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/7.jpg)
• Genetic information is especially found on thread-like structures called, chromosomes.
• Genes are located on chromosomes in the nucleus.
![Page 8: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/8.jpg)
• Genes and chromosomes are made of DNA.
• DNA stands for Deoxyribonucleic Acid.
![Page 9: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/9.jpg)
• DNA has a double helix shape and is made of 4 bases.
• The 4 bases are shown as; A, C, T and G
![Page 10: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/10.jpg)
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.
![Page 11: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/11.jpg)
Genes
• Genes are sections of DNA containing the instructions needed to make proteins which are made of amino acids.
![Page 12: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/12.jpg)
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
![Page 13: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/13.jpg)
• 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…
![Page 14: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/14.jpg)
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?
![Page 15: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/15.jpg)
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.
![Page 16: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/16.jpg)
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.
![Page 17: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/17.jpg)
Inheritance• Each person’s DNA is unique.• This is because they inherit their
genes from their parents.
![Page 18: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/18.jpg)
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.
![Page 19: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/19.jpg)
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?
![Page 20: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/20.jpg)
Inherited Diseases TaskCollect 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:http://learn.genetics.utah.edu/content/disorders/whataregd/ (Huntington’s and cystic fibrosis)
http://genome.wellcome.ac.uk/doc_wtd020857.html or http://www.genome.gov/10001214 (haemochromotosis)
http://www.genome.gov/10001220 (Tay Sachs)
![Page 21: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/21.jpg)
DNA StructureDNA 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.
![Page 22: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/22.jpg)
DNA StructureDNA 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.
![Page 23: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/23.jpg)
DNA Bracelet• From the sequence you have been
given make a bracelet to show the order of bases which codes for……
![Page 24: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/24.jpg)
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!
![Page 25: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/25.jpg)
Edible DNA!!• Follow the recipe to make your edible
DNA!
![Page 26: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/26.jpg)
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?
![Page 27: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/27.jpg)
Quick Check• What instructions does DNA carry?
• Where is DNA found in the cell?
• Where are proteins made in the cell?
![Page 28: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/28.jpg)
DNA to Protein• Watch the following video as an
introduction to DNA being used to make protein.
![Page 29: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/29.jpg)
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)
![Page 30: DNA](https://reader035.fdocuments.in/reader035/viewer/2022070423/568166d9550346895ddaf97d/html5/thumbnails/30.jpg)
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.