2a, 2b, 2c & 2d – Testing for the Presence or Absence of Substances (LC 2027) (Leaving Cert Biology): Flashcards
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Practise the cards
15 cards from this deck
Qualitative testing in biology
Qualitative testing in biology
Checking if a substance is present or absent
Qualitative vs quantitative test
Qualitative vs quantitative test
Qualitative: presence/absence; Quantitative: amount/concentration
Reagent for starch test
Reagent for starch test
Iodine solution
Why iodine detects starch
Why iodine detects starch
Iodine molecules fit into spiral structure of starch
Positive starch test color
Positive starch test color
Blue-black
Negative starch test color
Negative starch test color
Red-yellow
Reagent for reducing sugar test
Reagent for reducing sugar test
Benedict's or Fehling's solution
Examples of reducing sugars
Examples of reducing sugars
Glucose, fructose, maltose
Positive Benedict's test color change
Positive Benedict's test color change
Blue to red
Does Benedict's test require heating?
Does Benedict's test require heating?
Yes, in very hot water bath for 5 minutes
Reagent for protein test
Reagent for protein test
Biuret reagent
Positive protein test color
Positive protein test color
Purple-violet
Does Biuret test require heating?
Does Biuret test require heating?
No heating required
Test method for lipids
Test method for lipids
Brown paper test
Positive lipid test result
Positive lipid test result
Permanent translucent stain on paper