SC430 Molecular Cell Biology

• Welcome to Unit 5 Seminar with Dr Hall-Pogar

• Tonight we will discuss metabolism and the cells energy▫Arguments for and against forensic DNA analysis

▫I will be available at AIM:KaplanHallPogar before and throughout the seminar if you have any questions or issues.

• We will begin promptly at 8:00pmEST

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Unit Review• DB• Quiz• Project

▫ Real scientists that impacted molecular and cell biology James Watson, Gregor Mendel, and Frances Crick are applying

for a job with the research hospital in your community Include information to explain how his achievements could help

the hospital research disease treatment Cover letter should be 2-3 pages long and include important

information on his work or publications

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Forensic DNA analysis

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DNA Collection & Comparison

•Overview:▫Investigators gather samples from the crime

scene and from suspects and then analyze it for a set of specific DNA regions or markers.

▫A match of one marker is not usually unique, but if a sample matches four or five markers, there is a very good chance it is a match.

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DNA Collection & Comparison• DNA is collected at crime scenes in a

variety of ways using tools such as:▫ Smear slides, scalpels, tweezers, scissors,

sterile cloth squares, UV light, luminol and/or blood collection kits (for sample collection of suspects or living victims)

• DNA samples can be from:▫ Saliva, blood, hair strands, skin, finger or

toe nails, and/or a tooth with root material

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DNA Collection & Comparison• What happens after the samples are collected?

▫ A DNA profile is created….how?? Markers are found by designing small pieces of DNA

(probes) that will seek out and bind to complementary DNA sequences. This creates a distinct pattern. Again, one marker is not usually unique, but with four or five regions the match is likely

▫ The DNA profiles are compared with samples from suspects to find possible matches.

▫ If there are no suspects, a national database called CODIS may be used to find potential suspects.

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Sources of DNA at Crime Scenes

•Cool table at:▫http://www.dna.gov/basics/evidence_collecti

on/identifying

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How can DNA evidence be planted??•Sneezing or coughing over evidence•Person touches their mouth, nose or other

part of the face and then touches the area that may contain the DNA to be tested.

•Scene personnel can deposit hairs, fibers, or trace material from their clothing

•Wind can carry in contaminants

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Ethical Issues• In the USA, police are unable to force suspects to give samples due to

the 4th amendment Once a person’s DNA is sequenced, it is kept on record

• Most states do not require that the DNA is destroyed after it is looked at, so the sample may be available at later times for evidence.

• Stored samples increase the possibility that someone could get a hold another human being genome.

• Use of this information for genetic discrimination = not allowing people to obtain loans, work, or get health insurance

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Applications of the DNA

• Information stored on the DNA molecule is conveyed to RNA molecules through the process of transcription.

• The information contained in the RNA molecule is then used to produce proteins in the process of translation.

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Translation

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are needed to see this picture.

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Transcription Field Trip

• Watch this simplified animation:

• http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf

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Translation

• Watch this simplified animation:• http://www.stolaf.

edu/people/giannini/flashanimat/molgenetics/translation.swf

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