Exam 5 Review Topics (No metabolism) (1)

Aldose vs. Ketose
- Aldose: Sugar with an aldehyde group at the end of the carbon chain.
- Ketose: Sugar with a ketone group within the carbon chain.
- Both are classified as monosaccharides.
Enantiomer Definition
- Enantiomers: Molecular pairs that are mirror images but cannot be superimposed.
- Example: D and L forms.
Diastereomer Definition
- Diastereomers: Non-mirror image stereoisomers that differ at one or more stereocenters.
D and L Designations
- D-sugars: Hydroxyl (-OH) group is on the right at the furthest chiral carbon.
- L-sugars: Hydroxyl (-OH) group is on the left.
Anomer Definition
- Anomers: Cyclic monosaccharides that differ at C-1 (aldoses) or C-2 (ketoses).
- Example: α-D-Glucose and β-D-Glucose differ at the position of the -OH group.
Alpha and Beta Anomers
- Alpha anomer: Hydroxyl group on anomeric carbon points opposite the -CH2OH on carbon five.
- Beta anomer: Hydroxyl group on anomeric carbon points in the same direction as the -CH2OH on carbon five.

Common Monosaccharides
- Glucose
- Fructose
- Galactose
Common Disaccharides
- Formed through dehydration synthesis:
- Sucrose
- Maltose
- Lactose
Glycosidic Bond Definition
- Covalent bond linking carbohydrate molecules.
- Connects hemiacetal group of one sugar to hydroxyl group of another molecule.

Starch
- Storage form of glucose in plants, composed of amylose and amylopectin.
Cellulose
- Structural component of plant cell walls, serves as fiber for humans (indigestible).
Glycogen
- Major storage form in animals, has a branched structure for quick energy release.

Classes of Lipids
- Fatty Acids: Saturated and Unsaturated.
- Glycerides: Contain glycerol.
- Phospholipids: Include phosphoglycerides and sphingolipids.
- Glycolipids
- Steroids: Cholesterol.
- Complex Lipids: Lipoproteins.
General Structure of a Lipid
- Consists of a glycerol backbone and three fatty acid chains connected via ester bonds.
General Structure of Triglyceride
- Three fatty acids attached to a glycerol.

Unsaturated Fatty Acids
- cis isomer is most prevalent in nature; results in a bent chain.
- Trans isomer: Unnatural, linear chain.
Saturated Fatty Acid Definition
- No double bonds; solid at room temperature.
- Structure: CH3 (CH2)n COOH (where n = even number).

Unsaturated Fatty Acid Definition
- At least one double bond; typically liquid at room temperature.
- Types:
- Monounsaturated: One double bond.
- Polyunsaturated: Multiple double bonds.
Ester Bond Definition
- Formed between fatty acid and alcohol; releases a water molecule.
- Esterification: Reaction between carboxyl and hydroxyl groups.
Naming Omega Fatty Acids
- Based on first double bond position counted from omega carbon.
- Omega-3: Found in fish and plants.
- Omega-6: Found in vegetable oils.

Physical Properties of Triglycerides
- Colorless, non-polar, hydrophobic; appear as oils (liquid) or fats (solid).
Physical Properties of Oils
- Oils generally have higher proportions of unsaturated fatty acids.
- Saturated acids fit together easily; unsaturated have kinks, preventing solidification.
Hydrogenation Reaction
- Addition of hydrogen to double bonds; converts oils to solid fats.
- Example: Margarine is partially hydrogenated.
Structure of Phospholipids
- Two fatty acids attached to glycerol; phosphate group on the third carbon.

Structure of Sphingolipids
- Essential for cell membranes; based on sphingosine, which contains an amino group and an unsaturated hydrocarbon chain.
Function of Cholesterol
- Provides rigidity to animal cell membranes.
Types of Lipoproteins
- Macromolecular structures made from proteins and lipids, include enzymes, transporters, structural proteins, etc.