Practical Exam 1 Flashcards
an “educated guess” as to answer a scientific question
hypothesis
can be manipulated or changed by the researcher
independent variable
the observed (measured or counted) outcome of the test; depends on what is manipulated
dependent variable
all other variables that must remain constant during the test
control
name the scientific measurements (3)
meter, liter, kilogram
what does C.M.M.N stand for
centi, milli, micro, nano
list the four types of organic compounds
carbohydrates, lipids, proteins, and nucleic acids
heat the test tubes over an open flame and note the black residue in the test tube
how to test for organic components
contains copper ions in alkaline solution. when reagent is heated the copper ions turn a metallic copper
benedict’s test for reducing sugars
molecules get stuck in the spirals of another molecule and cause a blue-black color to appear.
iodine test for starch
a mixture of two liquids, each insoluble in the other
emulsion
molecule that is water-soluble on one end and lipid-soluble on the other.
emulsifier
a transparent to translucent spot
positive for a lipd
a solution of sodium hydroxide and copper sulfate turn a violet color because of a reaction with the peptide bods that link the individual amino acids
biuret reagent for proteins
the smallest unit of life
cell
have specialized structures called organelles
eukaryotic cells
do not have any internal membranes and no membrane-bound organelles
prokaryotic cells
particles tend to move from high concentration to low until a uniform distribution
diffusion
diffusion of water molecules through a semi-permeable membrane
osmosis
certain substances diffuse freely through the cell membrane without any expenditure of energy
passive transport
allows some particles to pass through while restrict the movement of others
selective permeability
random motion of particles suspended in a fluid resulting in a transfer of kinetic energy (heat)
brownian motion
proteins that act as catalysts
enzymes
molecule that the enzyme will alter
substrate