Download Indicators

Meat tenderizer contains an enzyme that interacts
with meat. If meat is coated with tenderizer
and then placed in a refrigerator for a short time,
how would the enzyme be affected?
(1) It would be broken down.
(2) Its activity would slow down.
(3) Its shape would change.
(4) It would no longer act as an enzyme.
Which statement concerning proteins is not
correct?
(1) Proteins are long, usually folded, chains.
(2) The shape of a protein molecule determines
its function.
(3) Proteins can be broken down and used for
energy.
(4) Proteins are bonded together, resulting in
simple sugars
Acids and Bases
Acids
•
•
•
•
•
Produce H+ ions
Taste sour
Change blue litmus to red
Has a pH less than 7
React with base to form salt and water
– Neutralization reaction
Bases
•
•
•
•
•
Produces OH- ions
Taste bitter
Change red litmus blue
Has a pH higher than 7
React with acid to form salt and water
– neutralization
pH scale
• Power
of
hydrogen
Measuring pH
• Indicators:dyes that will change colors in
the presence of acids or bases
– Some indicators only work in a specific pH
range
Indicators
Neutralization
• Acid + Base  salt + water
• HCl + NaOH  NaCl + HOH
A certain plant has white flower petals and it usually
grows in soil that is slightly basic. Sometimes the
plant produces flowers with red petals. A company
that sells the plant wants to know if soil pH affects
the color of the petals in this plant. Design a
controlled experiment to determine if soil pH affects
petal color. In your experimental design be sure to:
• state the hypothesis to be tested in the experiment
[1]
• state one way the control group will be treated
differently from the experimental group [1]
• identify two factors that must be kept the same in
both the control group and the experimental group
[1]
• identify the dependent variable in the experiment [1]
• state one result of the experiment that would support
the hypothesis [1]
• http://scienceview.berkeley.edu/showcase/
flash/juicebar.html