Online practical 2- algae for biofuel

when are algae non-stressed

high nitrogen conditions (ammonium)

when are algae stressed

low nitrogen conditions (ammonium)

6 features of non-stressed algae

• smaller & more numerous

• move faster

• flagella are visible

• darker colour in solution

• oval shaped

• see some organelles within cells

6 deaths of stressed algae

• larger & fewer

• move slower

• no flagella visible

• paler colour in solution

• rounder shaped

• granular bodies within cells

why are stressed algae larger & slower than non stressed

• creating storage products (starch & lipids)

• saving energy (photosynthesis is inhibited)

how to work out total magnification

objective lens * ocular

what does cell biovolume measure

accumulation of lipids & starch changing cell size/volume

relationship between cell biovolume and nitrogen concentrations

low nitrogen concentration = larger cell volume because of storage product creation (glycerolipids)

relationship between cell biovolume & glycerolipid content

positive correlation

how to calculate lipid content from cell biovolume

0.0204 * cell biovolume

relationship between number of cells & nitrogen concentrations

low nitrogen conditions = number of cells decreased

cholorophyll a maximum absorbance

430-665nm

chlorophyll b maximum absorbance

460-649nm

6 steps to extract chlorophyll from solution

• centrifuge solution for 5 mins

• discard (pipette out supernatant)

• add 1ml of ethanol to pellet

• re-suspend solution (mix cholorophyll & ethanol)

• add 4ml of ethanol

• centrifuge again

how to calculate concentration of cholorophyll a/b (2 equations)

relationship between cholorophyll concentration & nitrogen concentration

low nitrogen concentration = low chlorophyll concentration (nitrogen needed to make cholorophyll)