Carbohydrates Overview and Types

Carbohydrate Overview

• Carbohydrates are composed of carbon, hydrogen, and oxygen with a 1:2:1 ratio.
• Carbohydrates are a vital energy source for cellular metabolism, stored as glycogen, and are integral components of DNA and RNA.
• They account for 2-3% of total body mass.

Carbohydrate Types

• Monosaccharides: Simple sugars, containing 3-7 carbon atoms. Examples include glucose, fructose, galactose, ribose, and deoxyribose.
• Disaccharides: Formed by combining two monosaccharides through dehydration synthesis. Examples include sucrose, lactose, and maltose.
• Polysaccharides: Formed from tens to hundreds of monosaccharides linked via dehydration synthesis. Examples include starch, glycogen, and cellulose.

Hydrolysis

• A chemical reaction that breaks down complex molecules into simpler units.
• Involves the addition of a water molecule to split bonds.
• An example is the breakdown of sucrose (a disaccharide) into glucose and fructose.

Dehydration Synthesis

• A chemical reaction that combines smaller molecules to form a larger one.
• Involves removing a water molecule to create a new bond.
• An example is the formation of a disaccharide.

Monosaccharide Structures

• Monosaccharides have varying numbers of carbon atoms (3-7), categorizing them as trioses, tetroses, pentoses, hexoses, or heptoses.

Functions of Carbohydrates

• Energy Source: ATP production from glucose oxidation.
• Energy Storage: Glycogen in animals, starch in plants.
• Structural Component: Part of DNA and RNA.
• Receptors: Can act as receptors on cell surfaces to recognize other molecules.

Fate of Glucose

• ATP Production: Glucose is oxidized to produce ATP.
• Amino Acid Synthesis: Glucose is used in the formation of amino acids.
• Glycogen Synthesis: Glucose is stored as glycogen in liver and muscle cells.
• Triglyceride Synthesis: Excess glucose is converted to glycerol and fatty acids to synthesize triglycerides, stored in adipose tissue.