SL/AP Biology 9-19-05
2.2.8
State one function of a monosaccharide and one
function of a polysaccharide.
List two examples for each of monosaccharides,
disaccharides and polysaccharides.
2.2.9 State three functions of lipids.
2.2.10 Discuss the use of carbohydrates and
lipids in energy storage.
Syllabus Outline for 9-20-05
2.4.1 Outline DNA nucleotide structure in terms
of sugar (deoxyribose), base and phosphate.
– spatial arrangement is required.
2.4.2 State the names of the four bases in DNA.
2.4.3 Outline how the DNA nucleotides are
linked together by covalent bonds into a
single strand.
Syllabus for 9-21-05
• 2.4.4 Explain how a DNA double helix is
formed using complementary base pairing
and hydrogen bonds. (In other words, which
nucleotide bases pair in DNA?)
• 2.6.1 Compare the structure of RNA and
DNA (In other words, how are they
different sugar-wise and nucleotide basewise?)
Notes for 9-22-05
• A.2.3 List three sources of lipids in the diet
• A.2.6 List four sources of protein in the diet
• A.3.1 Discuss the significance of diets which are
rich in lipids in relation to obesity and coronary
heart disease.
• A.3.2 Explain the significance of saturated and
unsaturated lipids in relation to a healthy diet.
Protein Review
1. Proteins are polypeptides
2. Polypeptides are made with amino acid monomers.
Biuret Test
• Tests for protein
• Solution turns purple
when NaOH and CuSO4
are added to the substance
tested.
How does the Biuret test Work?
The Biuret reagent bonds to the peptide bond in a protein
and turns purple/violet (very simplistic explanation…)
Lipid Review
• Lipids are hydrophobic/non-polar
– They are non-polar because they have a lot of H-C
bonds. (The HYDRO-CARBON bond shares the
electrons equally, and this makes it nonpolar/hydrophobic.)
• Examples are triglycerides, phospholipids,
steroids…
Triglycerides are made like this:
Sudan Test for Lipid
• Put water into a test tube
• Put the substance that you are testing into the test tube
• Sudan dye is NON-POLAR and will cling to the NON-POLAR
lipid and turn it red.
• Soap is an emulsifier! Half of the soap molecule is polar, half is
non-polar. That is why everything mixes when soap is added!
Carbohydrate Review
• Carbohydrates are polysaccharides made
from long chains of monosaccharides.
• Carbohydrates are made from C,H,O.
• There is usually one oxygen for every
carbon.
Specific names for popular
carbohydrates
Iodine test for Starch/polysaccharide
Test for polysaccharide
Iodine test: How does it work?
• Polysaccharides wrap around iodine.
Polysaccharide
Polysaccharide wrapped around iodine
Benedict’s test for Monosaccharide
1. Add Benedicts to solution and heat.
2. If it turns orange, red, or brown, it has
monosaccharide.
Bennedict’s test for monosaccharide
The more Monosaccharides, the darker the red…
Blue
(No monosaccharide)
green
orange
red
brown
(The most monosaccharide)
How does the Benedicts test work?
(Cu++ ) + (Reducing Sugar) makes (Cu+)
So, if there is a monosaccharide in the solution, it
will give an electron to the Copper ion with a +2
charge and turn it into Copper Ion with a +1
Charge. This makes the bennedicts solution
change colors.