Website email
Download
1 / 50

website/email - PowerPoint PPT Presentation


  • 73 Views
  • Uploaded on
  • Presentation posted in: General

website/email. http://mscwan.wordpress.com mscwan2@gmail.com. TEST: Tues. February 7 th. identifying organelles and their functions DNA structure (nucleotide base pairing) protein synthesis (only at depth of textbook)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

website/email

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


website/email

http://mscwan.wordpress.com

mscwan2@gmail.com


TEST: Tues. February 7th

  • identifying organelles and their functions

  • DNA structure (nucleotide base pairing)

  • protein synthesis (only at depth of textbook)

  • types of mutations (addition, deletion, substitution; positive, negative, neutral)

  • causes of mutations (mutagens)

  • how gene therapy works


TEST: Tues. February 7th

  • Questions?


recap

  • mutagens cause mutations in DNA

  • mutations = change in genetic sequence  proteins not made properly


recap

  • positive = beneficial to survival

  • negative = detrimental to survival

  • neutral = no effect on survival


recap

  • addition = insertion of an extra base

    • TACTGC  TACCTGC

  • deletion = removal of a base

    • TACTGC  TACTC

  • substitution = switching of a base

    • TACTGC  TAATGC


recap

  • gene therapy is a highly experimental procedure to correct mutations

  • insertion of healthy gene into cold virus, which carries the gene to target cells

  • cell must activate healthy gene to synthesize correct amounts of the healthy protein


mitosis & cancer

30 January 2012


question

  • How does each cell in the body get a complete set of DNA when a cell divides?


which stage?

  • longest stage of the cell cycle

interphase


which stage?

  • spindle fibres pull chromosomes into a line

metaphase


which stage?

  • nuclear membrane breaks down

prophase


which stage?

  • spindle fibres contract and shorten

anaphase


which stage?

  • condensation of chromatin into visible chromosomes

prophase


which stage?

  • individual chromosomes not visible

interphase


which stage?

  • nucleolus disappears

prophase


which stage?

  • growth and DNA replication occurs

interphase


which stage?

  • spindle forms

prophase


which stage?

  • nuclear membranes start to re-form

telophase


which stage?

  • spindle attaches to centromere

prophase


which stage?

  • chromosomes aligned at cell equator

metaphase


which stage?

  • spindle fibres start to disappear

telophase


which stage?

  • sister chromatids pulled to opposite poles of the cell

anaphase


which stage?

  • cell membrane pinches to divide cytoplasm and organelles

cytokinesis


which stage?

  • one set of chromosomes at each pole of the cell

telophase


which stage?

  • centromere pulled apart

anaphase


which stage?

  • DNA loosely coiled so it can be transcribed into RNA

interphase


which stage?

  • nucleolus reappears

telophase


which stage?

  • shortest stage of mitosis

anaphase

*


  • “In Cell Division” song

  • http://www.youtube.com/watch?v=IlV9hExXZnM


question & discussion

  • Nina spent all summer tanning on the beach without any sunscreen. After feeling poorly for several months, she went to see a doctor, who told her that she had metastatic melanoma, and that there were tumours growing on her internal organs. How did she get cancer? How did it spread from her skin to her organs?


checkpoints


cancer

  • loss of cell cycle control (mutation in gene that codes for a checkpoint protein)

  • may lead to uncontrollable cell division


cancer


cancer


cancer

  • cancerous cells release chemicals that cause blood vessels to branch into tumour

  • nutrients delivered, tumour grows

  • cancerous cells may break away and be carried to other locations where they form a new tumour


cancer (extra)

30 January 2012


general facts

  • leading cause of death worldwide

  • lung, stomach, liver, colon and breast cancer cause the most cancer deaths each yr.

  • most frequent types of cancer differ between men and women.

  • About 30% of cancer deaths due to the five leading behavioural and dietary risks: high body mass index, low fruit and vegetable intake, lack of physical activity, tobacco use, alcohol use.


general facts

  • In the US, direct medical costs (total of all health expenditures): $102.8 billion


UV damage

  • “…key reaction on the DNA molecule that is linked to sunburn happens with astounding speed - in less than one picosecond.”

  • one picosecond = one trillionth of a second (10-12 seconds)

http://www.scienceagogo.com/news/20070101164743data_trunc_sys.shtml


UV damage

  • “Badly damaged cells simply die - the effect that gives sunburn its sting.”

  • “… chronic damage creates mutations that lead to diseases such as skin cancer.”

http://www.scienceagogo.com/news/20070101164743data_trunc_sys.shtml


UV damage

  • “UV-B light causes crosslinking between adjacent cytosine and thymine bases creating pyrimidine dimers. This is called direct DNA damage.

  • UV-A light creates mostly free radicals. The damage caused by free radicals is called indirect DNA damage.”

http://en.wikipedia.org/wiki/DNA_repair#Types_of_damage


free radicals

  • atom or group of atoms with an odd (unpaired) number of electrons

  • highly reactive


free radicals

  • as molecules react with oxygen in cellular respiration, they become free radicals, which are highly unstable and highly reactive

  • free radical goes around cell, ‘stealing’ electrons from stable molecules, rendering them unstable


free radicals

  • antioxidants


eating grilled red meat cancer?

  • The Nature of Things

    • “Myth or Science?”

    • original air date: November 24, 2011

    • http://www.cbc.ca/video/#/Shows/The_Nature_of_Things/1242300217/ID=2170768762


ad
  • Login