Catalyst
1. Identify each of the following as physical or
chemical changes:
ii.
iii.
iv.
A piece of wood is sawed in half for a bbq pit fire.
Melted butter solidifies in the refrigerator
Sugar is dissolved in a glass of tea
2. Identify each of the following as filtration,
distillation, or chromatography and justify why.
ii.
iii.
iv.
v.
Brewing Coffee
Evaporating and collecting pure water
Water Filter
Pouring a pot of boiling water and pasta into a strainer
Wikispaces
• A place to learn, collaborate, and showcase.
• You will create your own personal wikispace website
where you will host all of your groups’ work for the year.
• Open up 1.3.Building Your Own Wikispaces and follow
the steps!
Lecture 1.3 – Data
Analysis and Digestion
Data Analysis
• Data is everywhere and can be generated from
almost activity or observation!
• On the AP Exam, generating and interpreting data will
be the main focus of a vast majority of questions.
Density of Different Dairies
• So let’s learn how to be Dominant Data Digesters!
• Open the re-hashed Density of Different Dairies Lab, and
use lab notebooks to complete the missing components.
• On your new Wikispaces page, create a page titled
Density of Different Dairies Lab and upload your lab.
Questions
1. What is the general trend that is observed as the fat content of the dairy substance
increases? Use particulate level thinking to assess the characteristics of the
molecules that compose fat vs. molecules that compose water. Justify your answer.
2. Detail the accuracy and precision for your density values in the rows that you
completed. Use the literature values given for actual density. Calculate percent error.
3. Use the mass/volume data given to create a scatter plot graph. Add a trendline
and show the equation. What does the slope of the graph represent?
Aluminum Foil Transformer
• Create a table on excel using the RICE table template
depicted below and fill in the appropriate information.
Substances Present
Reaction
Observations
Physical/Chemical
2 Al + 6 HCL ---> 2 AlCl3 + 3 H2
Initial
Change
End
• Indicate which substances were
present initially, during the change, and
at the end.
• List your observations (visual, olfactory,
etc.) and determine whether or not
there is a physical or chemical change.
William Beaumont: The
Ultimate Data Collector
• The tale of Alexis St. Martin:
http://www.livescience.com/28996-holein-stomach-revealed-digestion.html
• In 1822, this man was shot in the stomach
and barely survived under the care of
army physician William Beaumont.
• However, a fistula (flap of skin that can
open) remained in his stomach, allowing
for extensive experimentation and
documentation…
• This is one of the main reasons we
understand digestion as well as we do.
Digestion
I. First, We Bite, Chew, and Gulp
• Do just that to the first sample on your table and think of any
physical or chemical changes you can demonstrate are
happening. How do you know that they are physical or
chemical?
• What chemical(s) could
be involved here?
• Is the chemical
composition being
changed?
• How do you know?
• Discuss Briefly.
II. Down the Hatch!
• Your lump of food has now been crushed and moisturized
into a bolus! This bolus passes by the epiglotis on its way
and travels down your esophagus via peristalsis.
III. Plop! Into the Stomach
• Stomach: Big Ol’ Paperbag-shaped muscle that squeezes
food and secretes acid to aid in digestion.
• What kind of changes are occurring here? Justify your
reasoning
IV. When Do We Get the Good Stuff?
• Food breaks down into a number of things, and these
usually get absorbed in the small intestine which is
connected to the stomach. Important components
include essential macromolecules!
• Macro = large
• Macro molecules = very large relative to actual molecules
• Check it out…Biology Flashback!
• Think about our awkward pillar as an example…
Macromolecules
I. Macromolecules
• Carbon atoms can
be joined together
to form many
different carbon
molecules
• Large compounds
formed by joining
many smaller
molecules together
are called
macromolecules
II. Monomers and
polymers
• Mono= 1
• Monomer = 1
molecule
• Monomers join
together to make
macromolecules
called polymers
• Poly= many
• Polymer= many
monomers joined
together
Four important
macromolecules
•
•
•
•
Carbohydrates
Lipids
Proteins
Nucleic acids
Carbohydrates
• Made of carbon,
hydrogen, and
oxygen
• Used as main
energy source for
living things
• Sometimes used as
structural support
o Plant walls and exoskeleton
Building carbohydrates
• Carbohydrates=
forms of sugars
• Simple sugars are
called
monosaccharides
• Monosaccharides
link up to form
polysaccharides
Structure of a
Carbohydrate
Glucose
ring structure
Rings connect to
form
polysaccharides
(polymer /
macromolecule)
Interesting fact: most
biology words ending in ose are sugars like glucose,
fructose, lactose, galactose
Sugars Colloids include:
• Agar and Pectin Gels
• Pectins hold cell walls together. When fruit ripens,
enzymes are released that break down pectin and
make the fruit get soft.
Kitchen Fact:
Agar uses another sugar knows as galactose as a base instead of simple glucose.
Lipids
• Examples: Fats, waxes, oils
• Made mostly of carbon and
hydrogen
• Used to store energy
• Hydrophobic=scared of water
Kitchen Fact:
Butter is composed of about 80-82% fat, 16-17% water, and 1% proteins and other
lipid structures. This gives butter it’s unique characteristics
Building lipids
• Made of 3 fatty acids
attached to glycerol
• Different types of fats
Saturated fats (ex. butter)
Unsaturated fats (ex. oil)
Fatty Acid
Fatty Acid
Fatty Acid
Lipid Colloids include:
• Many emulsions use phospholipids
such as lecithin to stabilize
hydrophobic and hydrophilic
substances
• Found in egg yolk, but usually
extracted commercially from
cheaper alternative, soybeans.
• Mayonnaise use lecithin and egg
protein, plus the phospholipids in
ground mustard to stabilize it into
that silly goo that tastes so good
on sandwiches!
• Clarified butter is butter that has
been heated until the emulsion
breaks and the water and milk
solids fall to the bottom, leaving
pure butterfat at the top.
Proteins
• Some help
chemical reactions
happen faster
• Some help support
cell structure
• Can also be used
for energy
Building proteins
Made up of amino acids
Different order of amino acids = different
proteins
Must be folded correctly to work
Protein Colloids include:
• Cooked egg white is a gel formed when the
albumin proteins in the egg white open from their
natural folded shape due to heat and then bind to
one another in many places.
• Collagen is the main connective protein in the body
and is made of a triple helix of proteins. When
heated and cooled, they form gelatin (melting
point < 95 Fo) – a substance that gives food items
carrying it a delicious “mouth feel.”
Nucleic Acids
• Stores and passes along
genetic material
• 2 types: DNA and RNA
• Made of strands of
nucleotides, which have
a base made of nitrogen
Building nucleic acids
The building
blocks of nucleic
acids are
nucleotides
Nucleotides
DNA (double Stranded)
Adenine (A)
Cytosine (C)
Guanine (G)
Thymine(T)
RNA (single stranded)
Adenine(A)
Cystosine (C)
Guanine(G)
Uracil (U)
Bottom line
All macromolecules are synthesized (made)
from simple precursors (building blocks)
Monosaccharides
Fatty acids
Amino acids
Nucleotides
Building X Multiple
Block
Units
polysaccharides
lipids
proteins
nucleic acids
Macromolecule
All The Macros at Once?
• A company called soylent thinks it has the answer…
What’s in my Food
and Food Macromolecule Lab
• Use http://scioly.org/wiki/index.php/Food_Science
as a guide.
• Press Command
+ F and search for each of the
specific tests if you are in need of help.
Lab Work Time
Lab Follow-Up
• Please complete the section labeled “Lab Follow-Up” in
your packet.
Closing Time
• Complete problem sets by Thursday/Friday
• Complete Post-lab for Lab 3.