diff --git a/experiments/02-Secondary level education/01-control-testing.md b/experiments/02-Secondary level education/01-control-testing.md index aa62ea22a..abd1d7f87 100644 --- a/experiments/02-Secondary level education/01-control-testing.md +++ b/experiments/02-Secondary level education/01-control-testing.md @@ -55,5 +55,4 @@ These kinds of tests make it easy to identify any unusual activity occuring in a 6. Select _Manage all Pioreactors_, and start _Stirring_ activity, _Temperature automation_ activity (set to an optimal temperature; ex. 30°C) and _OD reading_ activity. 7. Confirm that everything looks normal (ex: receiving optical density signal). 8. Back on the _Pioreactors_ page, select _Manage all Pioreactors_ and start _Growth rate_. It will take a minute for results to begin showing up. -9. Watch growth progress on the _Overview_ page. - +9. Watch growth progress on the _Overview_ page. \ No newline at end of file diff --git a/experiments/02-Secondary level education/salt-stress-on-yeast.md b/experiments/02-Secondary level education/salt-stress-on-yeast.md index 3f123f1a5..f20b106d1 100644 --- a/experiments/02-Secondary level education/salt-stress-on-yeast.md +++ b/experiments/02-Secondary level education/salt-stress-on-yeast.md @@ -31,13 +31,13 @@ Use your Pioreactor to model how cells are affected by high salt (hypertonic) so ## Introduction -In early biology classes, students learn the core concepts of osmolarity across a cell's membrane. The cell's environment can contain different concentrations of impermeable molecules, creating osmotic pressure and resulting in water entering or leaving the cell. You can quantitatively measure the effect this has on growth rate using your Pioreactor! +In early biology classes, students learn the core concepts of osmolarity across a cell's membrane. The cell's environment can contain different concentrations of impermeable molecules, creating osmotic pressure and resulting in water entering or leaving the cell. You can quantitatively measure this effect on growth rate using your Pioreactor! The inside and outside of a cell are separated by the cell's **semi-permeable** membrane. Only water and certain molecules can pass through via active or passive transport (diffusion). All other molecules are **impermeable** and cannot pass through the membrane. We'll refer to these as **solutes**. -Through the process of osmosis, water (our **solvent**) is drawn across a cell's membrane towards higher concentrations of solutes, until an equilibrium is reached. If the concentration of solutes inside and outside of a cell are the same, then the cell is in an **isotonic** solution. Less external solutes or more solutes create **hypotonic** and **hypertonic** solutions, respectively. +Through the process of osmosis, water (our **solvent**) is drawn across a cell's membrane towards higher concentrations of solutes, until an equilibrium is reached. If the concentration of solutes inside and outside a cell is the same, then the cell is in an **isotonic** solution. Less external solutes or more solutes create **hypotonic** and **hypertonic** solutions, respectively. -Increasing salt content to create a hypertonic solution will slow the yeast's fermentation or reproductive activities, leading to slower growth. As salt is addded in excess, yeast cells will fail to grow; yeast needs water and their cell volume eventually becomes too small for growth. +Increasing salt content to create a hypertonic solution will slow the yeast's fermentation or reproductive activities, leading to slower growth. As salt is added in excess, yeast cells will fail to grow; yeast needs water and their cell volume eventually becomes too small for growth. ## Experiment diff --git a/experiments/02-Secondary level education/yeast-growth-by-temperature.md b/experiments/02-Secondary level education/yeast-growth-by-temperature.md index 8dbdbbc12..4111d444d 100644 --- a/experiments/02-Secondary level education/yeast-growth-by-temperature.md +++ b/experiments/02-Secondary level education/yeast-growth-by-temperature.md @@ -56,7 +56,7 @@ Though subtle, non-linear patterns of growth rate are observed between the tempe |36°C|0.76|7.5 hours| |40°C|0.59|9.5 hours| -Rather than increasing as temperature increases, the higherst growth rates form a bell-curve, with the highest overall growth rate of **0.76 h⁻¹** occuring at 36°C. It decreases at 40°C, since this temperature lies outside of the ideal temperature range for yeast. +Rather than increasing as temperature increases, the highest growth rates form a bell curve, with the highest overall growth rate of **0.76 h⁻¹** occurring at 36°C. It decreases at 40°C since this temperature lies outside of the ideal temperature range for yeast. The time it takes for each culture to reach the stationary phase is also related to the peak growth rates. Cultures that peaked higher did so in a quicker time frame, thus reaching the stationary phase sooner! Consider the extremes in this case: what would happen if we drop the temperature? Increased it to 50°C? How does this relate to cooking and food storage? diff --git a/experiments/03-University level education/00-continuous-cultures-using-turbidostat.md b/experiments/03-University level education/00-continuous-cultures-using-turbidostat.md index ed940e4d0..213773013 100644 --- a/experiments/03-University level education/00-continuous-cultures-using-turbidostat.md +++ b/experiments/03-University level education/00-continuous-cultures-using-turbidostat.md @@ -62,7 +62,7 @@ Over time, we expect faster growing yeast to out-compete slower growing yeast, r ## Recommendations -There are a myriad of further applications for turbidostats, such as characterization of species, directed evolution, responses to stimuli (gene regulating metabolites) and so much more. +There is a myriad of further applications for turbidostats, such as characterization of species, directed evolution, responses to stimuli (gene-regulating metabolites) and so much more. We encourage you to choose species and media compositions to suit your interests. Have fun!