5 resultados para rye

em Brock University, Canada


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The number of P700 (the reaction centre of Photosystem I) converted to P700+, in winter rye, was determined by measuring the absorbance change at 820nm . It was found, with a single turnover flash, that thylakoids isolated from cold grown plants have a 50% greater number of P700 oxidized than thylakoids isolated from warm grown plants. Incubation of thylakoids in the dark at 35 C did not change the number of P700 oxidized. The conversion of P700 to P700+ with a single flash can be compared to a steady state rate of electron transport using a Clark electrode. The results for P700 oxidation using the absorbance change at 820 nm measure effects within the PSI complex whereas the results obtained from a Clark electrode measures steady state electron transport between the cytochrome blf complex and the PSI complex. In contrast to the results for P700 oxidation it was shown, using a Clark electrode, that both thylakoids from cold grown plants and thylakoids incubated at in the dark 35 C exhibited 50% higher rates of electron transport than thylakoids from warm grown plants. The correlation between the higher rate of steady state PSI electron transport observed in thylakoids isolated from cold grown winter rye and number of active PSI reaction centres localizes the site of the increase to the PSI reaction centre. In contrast the lack of correlation after incubation at 35 C indicates the increase in the rate of light saturated electron transport in thylakoids isolated from cold grown plants and thylakoids incubated in the dark at 35 C occur by different mechanisms.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Low temperature (77K) linear dichroism spectroscopy was used to characterize pigment orientation changes accompanying the light state transition in the cyanobacterium, Synechococcus sp. pee 6301, and cold-hardening in winter rye (Secale cereale L. cv. Puma). Samples were oriented for spectroscopy using the gel squeezing method (Abdourakhmanov et aI., 1979) and brought to 77K in liquid nitrogen. The linear dichroism (LD) spectra of Synechococcus 6301 phycobilisome/thylakoid membrane fragments cross-linked in light state 1 and light state 2 with glutaraldehyde showed differences in both chlorophyll a and phycobilin orientation. A decrease in the relative amplitude of the 681nm chlorophyll a positive LD peak was observed in membrane fragments in state 2. Reorientation of the phycobilisome (PBS) during the transition to state 2 resulted in an increase in core allophycocyanin absorption parallel to the membrane, and a decrease in rod phycocyanin parallel absorption. This result supports the "spillover" and "PBS detachment" models of the light state transition in PBS-containing organisms, but not the "mobile PBS" model. A model was proposed for PBS reorientation upon transition to state 2, consisting of a tilt in the antenna complex with respect to the membrane plane. Linear dichroism spectra of PBS/thylakoid fragments from the red alga, Porphyridium cruentum, grown in green light (containing relatively more PSI) and red light (containing relatively more PSll) were compared to identify chlorophyll a absorption bands associated with each photosystem. Spectra from red light - grown samples had a larger positive LD signal on the short wavelength side of the 686nm chlorophyll a peak than those from green light - grown fragments. These results support the identification of the difference in linear dichroism seen at 681nm in Synechococcus spectra as a reorientation of PSll chromophores. Linear dichroism spectra were taken of thylakoid membranes isolated from winter rye grown at 20°C (non-hardened) and 5°C (cold-hardened). Differences were seen in the orientation of chlorophyll b relative to chlorophyll a. An increase in parallel absorption was identified at the long-wavelength chlorophyll a absorption peak, along with a decrease in parallel absorption from chlorophyll b chromophores. The same changes in relative pigment orientation were seen in the LD of isolated hardened and non-hardened light-harvesting antenna complexes (LHCII). It was concluded that orientational differences in LHCII pigments were responsible for thylakoid LD differences. Changes in pigment orientation, along with differences observed in long-wavelength absorption and in the overall magnitude of LD in hardened and non-hardened complexes, could be explained by the higher LHCII monomer:oligomer ratio in hardened rye (Huner et ai., 1987) if differences in this ratio affect differential light scattering properties, or fluctuation of chromophore orientation in the isolated LHCII sample.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

George William Schram (1809-1885), son of Garrett Schram and Leah Van Etten, married Orpha Pearson on Nov.13, 1835. His son Marsena John Schram (farmer) was born in May of 1840, in Canada. He died on Nov. 17, 1926 in Wexford County, Michigan. He was married in 1867 to Sarah (1825-1887).Marsena married again on April 18, 1910 to Ann Clarinda Warner (1861-1924). He was working as a carpenter at this time. They had another son, William who was born about 1838 and he married Sabina Chambers on Jan. 21, 1862. The 1861 census for Wainfleet lists siblings of Marsena John Schram as Sarah J. (age 14), Georgiana (age 5), and William (age 21). The Schrams lived on Concession 5 and owned approximately 144 acres of land. David Thompson was born Feb. 4, 1873 and died Feb. 19, 1951. He married Sally Ann Wilson on Sept. 7, 1825 in Pelham. She died about 1840 in Indiana Ontario (near Cayuga). Lemuel Victor Hogue was born Dec.1, 1854 and died Jan. 12, 1929. He was married to Elizabeth Wills who was born Aug. 2, 1861 and died Mar. 8, 1926. Sources: http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=99294842 http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?op=GET&db=seadragon5&id=I91708

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A price list form for the Alberta Liquor Control Board from 1 January 1925. The price list includes "General Information" in regards to permits for individuals and special permits. The alcohol is then listed by category for pricing: Scotch Whisky, Irish Whisky, Rye Whisky, Bourbon Whisky, Rum, Gin, Brandy, Port, Native Wine, Italian (Type) Wines, Sherry, Claret, Burgundy, White Wine, Sparkling Wine, Vermouth, Cocktails, Liqueurs, Champagne, Bitters, Ale and Stout, Chinese Liquors.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A collection of Gooderham's labels that include: Bonded Stock Canadian Whisky, London Dry Gin, Big Brown Jug Canadian Rye Whiskey, and Rich and Rare Canadian Whiskey. The labels indicate the distillery was established in 1832, Toronto, and is Canada's first.