Lab Mid: Notes Flashcards
(89 cards)
what causes surface tension of water,
attration of water molecules at the surface of the water
Which atom in water is positive? negitive?
H+, O-
What is pH the measure of
the acidity of the solution
Solutions with a pH lower than 7 are considered _____ while ones with greater pH are considered _______
acidic, basic
What do buffers do
Buffers help to maintain pH at a constant value in living organisms
What makes up a buffer
a weak acid and a weak base
What is a conjugate base
a base that is formed when an acid loses its H+ (H+ is the ‘acidic’ part of the molecule
What is a polymer composed of
monomers
What 4 classes of organic molecules make up most living organisms
carbohydrates, proteins, lipids, and nucleic acids
What are indicator solutions
solutions that will chance colors when a specific substance is detected
When a color reaction occurs in an indicator solution we call ths a ______ result
positive
When no color reaction occurs in an indicator solution we call ths a ______ result
negitive
If we include samples that we know will give a postive result we call it:
positive control
If we include samples that we know will give a negative result we call it:
negative control
__________ ________ tests for the presence of simple sugars or monosaccharides which have free ketone or aldehyde functional groups
Benedicts reagent
What does benedicts reagent test for
the presence of simple sugars or monosaccharides which have free ketone or aldehyde functional groups
What color represents a negative result in a benedicts reagent? positive?
neg: blue
Pos: reddish-orange
What kind of sugar will not cause a a color change with benedicts reagent
Sucrose (table sugar) is a disaccharide and therefore will not prompt a positive result
___________ ____________ will detect large carbohydrates called staches
Iodine-Potassium Iodide (I2KI)
Iodine-Potassium Iodide (I2KI)
detects large carbohydrates called staches
What color represents a negative result in a Iodine-potassium iodide? positive?
Neg: amber/dark brown
Pos: black-blue color
______ _______ tests for the presence of peptide bonds in proteins
Biurets reagent
What does Biurets reagent test for
the presence of peptide bonds in proteins
What color represents a negative result in a biurets reagent? positive?
Neg: light blue
Pos: Darker purple