Carbohydrates Overview Quiz

Carbohydrates Overview

• Composed of carbon, hydrogen, and oxygen.
• Monosaccharides (simple sugars) have a 1:2:1 atom ratio; formula: (CH2O)n.
• Characteristically sweet-tasting and often identified by names ending in -ose.
• Functional groups present: Carbonyl (aldehyde or ketone) and hydroxyl groups enhance solubility.

Functions of Carbohydrates

• Serve as energy sources.
• Provide structural support.
• Facilitate cell-to-cell communication.
• Raw materials for building amino acids, lipids, and nucleic acids.
• Functionality is linked to the carbohydrate's structural makeup.

Isomers

• Isomers possess the same chemical formula but differ in atom arrangement leading to varied chemical properties.

Types of Carbohydrates

• Monosaccharides: Single sugar unit, simplest form; include glucose (widely used), and can be triose, pentose, or hexose.
• Disaccharides: Formed by two sugar subunits; examples include sucrose (table sugar) and lactose (milk sugar).
• Polysaccharides: Complex carbohydrates consisting of many monosaccharides; variations in structure based on glycosidic linkages.

Monosaccharides

• The sweetest sugars, with glucose being the most common.
• Exist in linear or ring forms, especially in water.
• Functions: short-term energy storage (e.g., glucose) and building blocks for nucleic acids (e.g., ribose, deoxyribose).
• Linked by glycosidic bonds between carbon atoms.

Disaccharides

• Generally used for short-term energy storage.
• Less sweet than monosaccharides due to more subunit linkages.
• Examples: maltose (used in brewing), sucrose (sweetener), lactose (milk sugar).

Polysaccharides

• Highly varied 3D structure, composed of numerous monosaccharides.
• Water solubility is low due to their large size, despite polar functional groups.
• Polymerization:
  • Alpha-glucose forms linear chains through 1-4 glycosidic linkages; side branches through 1-6 linkages.
  • Beta-glucose requires flipping for proper chain packing.

Functions of Polysaccharides

• In Plants: Long-term energy storage (amylose, amylopectin), structural support (cellulose).
• In Fungi: Structural support through chitin.
• In Animals: Long-term energy storage and structural support (exoskeletons in insects/crustaceans).

Lipids Overview

• Characteristically amphiphilic, containing both hydrophilic and hydrophobic regions.
• Composed mainly of carbon and hydrogen; largely non-polar.
• Structurally based on fatty acids, classified into 5 classes: fatty acids, fats/oils, phospholipids, steroids, and waxes.

Fatty Acids

• Structural traits: Hydrocarbon chain (4+ carbons) with a carboxyl group at one end, rendering acidic properties.
• Types of fatty acids:
  • Saturated: No double bonds, linear shape, tightly packed, solid at room temperature.
  • Unsaturated: Presence of double bonds, causing kinks in the chain, resulting in looser arrangement, generally liquid at room temperature.