See the experiment and then answer the questions The effects of the variables te
ID: 148463 • Letter: S
Question
See the experiment and then answer the questions
The effects of the variables tested are best determined by comparing each individual variable to its own control, rather than attempting to compare all seven tubes at once. Consult the set-up and data collection table from Procedure 1. For each variable tested (listed below), determine which two tubes can best be compared to determine the effect of the variable on CO production in yeast and record th tube pairs in the bolded columns of the table below. Questions to answer AFTER collecting data: 8. Tube # | Control | Variable made CO2 | tube # for | production increase Why? with variablevariableor decrease? Variable l Yeast Glucose NaF Pyruvate MgSO, 9. For each variable, record whether the variable INCREASED or DECREASED CO, production in the table above. In the last column, explain the cause of the effect seen, consulting the description of the variables in the Background section as well as your hypotheses on the previous page. 10. Which of the variables tested would you say were inhibitors? Answer 11. Which of the variables tested would you say were activators?Explanation / Answer
Variable Tube# Control Tube# CO2 production increased Why?
with variable for variable or decreased
Yeast 1 7 increased Tube 7 which lacks yeast cells has no net CO2 production. Addition of actively respiring yeast cells led to increase in carbon dioxide release as a result of fermentation.
Glucose 2 1 increased Glucose acts as a carbon source for yeast cells, addition of glucose to yeast cells leads to increased fermentation rate and hence more CO2 production.
NaF 4/5 2 decreased NaF is an inhibitor of the glycolytic enzyme enolase. Addtion of NaF to dividing yeast cells, decreased fermentation rate of yeast cells and hecne there is a decrease in CO2 production.
Pyruvate 6 5 increased Glycolysis is the conversion of glucose to two molecules of pyruvate. Addition of NaF, leads to inhibition of glycolysis in the control tube (tube 5), whereas supplementing NaF inhibited yeast cells with pyruvate, provided a substrate for CO2 production and hence CO2 release.
MgSO4 3 2 increased Magnesium ions are a cofactors of many glycolytic enzymes. Increasing magnesium ions increase the rates of these enzymes and hence increased fermentation rate.