and a 1, and a 2…
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and a 1, and a 2…. Examples of counting and clock-keeping in biology N Kuldell for 20.020(S10) 02.18.09. And a 1: telomeres. (TTAGGG)n. And a 1: telomeres. (TTAGGG)n. 3’. Telomeric DNA with overhanging 3’ end. 5’. Telomerase and telomerase RNA bind overhang. 3’. - PowerPoint PPT PresentationTRANSCRIPT
and a 1, and a 2…
Examples of counting and clock-keeping in biology
N Kuldell for 20.020(S10)
02.18.09
And a 1: telomeres
(TTAGGG)n
And a 1: telomeres
(TTAGGG)n
Telomeric DNA with overhanging 3’ end
3’
5’Telomerase and telomerase RNA bind overhang
Telomeric DNA with overhanging 3’ end
3’
5’Telomerase and telomerase RNA bind overhang
Cell type Telomerase Telomere length
Normal Somatic OFF shortens
Counting Cell Divisions with Telomere Repeats
Cell type Telomerase Telomere length
Normal Somatic OFF shortens
Cancerous ON forever stable
Counting Cell Divisions with Telomere Repeats
“Astragaloside IV, found in minute traces in Astragalus Membranaceus extract, is known to turn this gene on and 'activate' telomerase.
http://www.terraternal.com/Astragaloside_Telomerase.html?pid=2
And a 2: bud scar countinghttp://organelleview.lsi.umich.edu/orgview2/
And a 2: bud scar counting
Annu. Rev. Biochem (1998) 67:307
And a 2: bud scar counting
Annu. Rev. Biochem (1998) 67:307
Microbiology (2003)149:3129
And a 3: circadian rhythmsOscillation of alertness, sleep, hormone
production, body temperature and organ function
Electronics: van der Pol oscillatorL = inductor
C = capacitor
V = vacuum tube containing a tetrode
I = voltage supply
And a 3: circadian rhythmsOscillation of alertness, sleep, hormone
production, body temperature and organ function
Hydraulic Model Negative feedback loop
>>water flows into B then through T1 into A and out through T4
>>level of A connected to T3 and T2 which drain A as level rises
And a 3: circadian rhythmsOscillation of alertness, sleep, hormone
production, body temperature and organ function
Molecular clocks: transcriptional-translational feedback
>>RNA is made
>>turns protein production on
>>protein turns off RNA production
>>absence of RNA turns off protein production
and a 1, and a 2, and a 3
the end