lab 6 (proteins ii) Flashcards
would e-coli rather feed on glucose or lactose?
lactose
what enzyme is required to split lactose in e-coli?
b-gal
in what situation can b-gal be present/lac operon to be active?
glucose is scarce or lactose is present
why did the ONPG substrate turn yellow?
a chemical that breaks down in yellow colour of b-gal is active
what is an ANOVA test?
analysis of variance between groups
what is the independent variable in this lab?
sugar conditions (no sugar, lactose, glucose, lactose + glucose)
what is the dependent variable in this lab?
absorbance reading at 440nm, indicating b-gal activity
what does a yellow solution in the flask mean?
b-gal is active and the lac operon is on
what happens when both glucose and lactose are present?
glucose represses b-gal production, even if lactose is available
what hypothesis is being tested in this lab?
e-coli produces b-gal only when lactose is present, and glucose represses this production
how does glucose affect the lab operon?
when glucose levels are high, cAMP levels are low, and the CAP protein cannot bind, reducing the operon’s activity
what is b-gal?
enzyme produced by e.coli
what does b-gal do?
breaks down lactose into glucose and galactose
what is the main objective of this lab?
how the presence of lactose and glucose affects B-gal production
where is b-gal found?
e.coli bacteria
