Review – Carbohydrates,
Lipids, & Proteins

THEME – Structure Dictates Function
Main Ideas
1) structure
2) transmission of genetic info.
3) metabolism

Mono di oligo poly saccharides

Glucose:
___ C’s aldehyde/ketone
Fructose
___ C’s aldehyde/ketone

Stereoisomers
# isomers = options positions

Recognizing structural relations:
For each of the following pairs of compounds, indicate whether the pair consists of different compounds that are (1) constitutional isomers or (2) stereoisomers that are enantiomers or (3) stereoisomers that are diastereomers or (4) not isomers.
(a) D-Glucose and D-mannose (3) Diastereomers; they are stereoisomers that are not enantiomers
(b) D-ribose and D-xylulose
(1) Constitutional isomers; D-ribose is an aldopentose and D-xylulose is a ketopentose
(c) D-fructose and D-arabinose
(4) Not isomers; D-fructose is a hexose and Darabinose is a pentose
(d) D-sorbose and L-sorbose
(e) D-sorbose and D-fructose
(2) Enantiomers; they are nonsuperimposable mirror images
(3) Diastereomers; they are stereoisomers that are not enantiomers

Fischer
Projection
Haworth
Projection
Aldoses exist primarily as hemiacetals.

Fischer
Projection
Haworth

10.4 Chem. & Phys. Prop. of Monosaccharides
Monosaccharides solubility in water ________________ phase at room temp. ________________ highly concentration solutions are ____________ solubility in alcohols ________________ solubility in ethers & hydrocarbons _______________ taste ________________

10.4 Chem. & Phys. Prop. of Monosaccharides
The Oxidation of the Aldehyde group/Benedicts Test
Aldose + Cu 2+  carboxylic acid + Cu
2
O a
-hydroxy ketones like fructose are converted to aldoses in the alkaline
Benedicts soln, thus give a __________ test.

10.4 Chem. & Phys. Prop. of Monosaccharides starch (a polymer) gives a ______________ test
Maltose (a disaccharide) gives a ___________ Benedict’s test.

a,b
,Linkages and Benedicts Test Review

Ch. 11-What you really need to know …
1) What is a lipid (recognize structure)?
2) What is a fatty acid?
(draw structure)
3) Write the reaction for forming a triglyceride and the saponification of a triglyceride.
4)
What’s the difference between a saturated and an unsaturated fat? How does that relate to their m.p. and what phase they are at room temperature?
5) Fat soluble vs. water soluble vitamins?

Carbohydrates & Lipids -
Provide energy, precursors to
Both Energy fat 9.2 kcal/g biomolecules, construct cell carbs 4 kcal/g membranes
Proteins – Catalytic, transport, regulatory, structural, contractile, protective, storage
Variety of roles due to complexity/diversity of structure in protein folding
Nucleic Acids transmission of genetic info.

KEY: Know structure of fatty acids and triglycerides. The rest are simply “mostly nonpolar”

Fatty Acid -
Almost exclusively the linear
(unbranched) acids with even #’s C’s
C=C almost always cis

Trans -fats?

11.3 The Structure and Physical
Properties of Triacylglycerols

11.4 Chemical Reactions of
Triacylglycerols
Hydrolysis:

Amino Acid Structure

12.2 The Zwitterion Structure of a
-amino acids
• amino acids can react with themselves to form a zwitterion

12.2 The Zwitterion Structure of a
-amino acids
• pH changes affect the structure of amino acids

Peptide –
a polyamide formed from amino acids linked by peptide bonds
Polypeptide – a few to hundreds/thousands of amino acids
Protein – Usually 2+ polypeptides (along with other molecules or ions) peptide formation:

12.5 The 3-D Structure of Proteins
Simple Protein –
Conjugated Protein

12.5 The 3-D Structure of Proteins
Levels of Structure
Primary (1º)
Amino acid sequence
Secondary (2 º ) Conformation in a local region
Tertiary (3 º ) When diff. 2 structures in diff. local regions interact
Quaternary (4 º ) 3D relation among diff. proteins

What gives rise to conformation stability
1) Shielding of nonpolar amino acids from water
2) Hydrogen bonding between peptide groups
3) Attractive interactions between side groups of amino acids.
4) Attractive interactions of side groups of polar amino acids with water
5) Disulfide bridges

12.5 The 3-D Structure of Proteins
3)Attractive interactions between side groups of amino acids.
a. Hydrophobic attractions b. Hydrogen bonding c. Salt-bridge
4)Attractive interactions of side groups of polar amino acids with water ex. globular proteins fibrous proteins

12.5 The 3-D Structure of Proteins
What type of attraction would exist between side chains of the following amino acids?
a)Pro-His b)Ser-Tyr c)Pro-Phe d)Lys-Glu e)Ser-Val

Positive Test Colors
TEST Positive Color
Iodine
For starch
Benedicts
For a-hydroxy aldehydes and ketones
Ninhydrin
For amino group on amino acids
Biuret
For peptide group on proteins blue / black red blue purple

Sudan III
 Dissolves in nonpolar solvents (lipids)