Carbohidratos - Azúcares y Tipos

Carbohydrates - Saccharides - Sugars

• Carbohydrates are a quick energy source (sugars) and store energy (starches).
• They also provide structural support (cellulose in plant cell walls, glycogen).
• Carbohydrate molecules are composed of oxygen, hydrogen, and carbon.
• The ratio of elements is 1:2:1 (C:H:O).
• The general formula is (CH₂O)ₙ.
• Examples include glucose (C₆H₁₂O₆).

Types of Carbohydrates

• Carbohydrates are classified as simple or complex.
• Simple carbohydrates include monosaccharides (glucose, fructose, galactose) and disaccharides (maltose, lactose, sucrose).
• Complex carbohydrates include polysaccharides (starches, fibers, glycogen).

Types of Carbohydrates (Detailed)

• Complex Carbohydrates:
  • Grains (oats, rice, bread, noodles)
  • Starchy vegetables (potatoes, sweet potatoes, yams)
• Simple Carbohydrates:
  • Sugars (white, brown, rock sugar, gula melaka, syrup, honey)
  • All types of fruits
  • Desserts and sweets
• Fiber:
  • Whole grains
  • Nuts
  • Legumes
  • Milk (full-cream, low-fat, skimmed milk)

Monosaccharides

• Monosaccharides are single-unit sugars (monomers).
• Glucose, fructose, and galactose are common examples.
• Glucose exists in both a chain and a ring structure.
• These isomers are different structural arrangements of the same chemical formula.

Ring Structure of Monosaccharides

• A carbon atom with one OH and two H groups forms a side chain
• A ring of atoms, mostly carbon, excluding one oxygen atom.
• Carbon atoms in the ring that do not have a side chain are attached to an H and OH group.
• Ribose (5-carbon) is a pentose and glucose (6-carbon) is a hexose.

Glucose

• Glucose is soluble in plasma and is a stable molecule for energy storage.
• It's stored as glycogen or starch.
• It is a substrate for cellular respiration.

Disaccharides

• Disaccharides are formed by combining two monosaccharides through condensation reactions.
• glucose + glucose → maltose + H₂O
• glucose + galactose → lactose + H₂O
• glucose + fructose → sucrose + H₂O

Maltose

• Maltose is formed from two glucose molecules bonded together with an α-1,4-glycosidic bond.

Lactose

• Lactose is formed from glucose and galactose with a β-1,4-glycosidic bond.

Sucrose

• Sucrose is made from glucose and fructose joined by a glycosidic bond.

Polysaccharides

• Polysaccharides are complex carbohydrates formed from chains of simple sugars.
• Cellulose, glycogen, and starch are examples.
• Cellulose is an important structural component in plant cell walls with an unbranched structure.
• Starch is a storage form of glucose in plants.
• Glycogen is a storage form of glucose in animals.

Starch

• Starch is a polymer of α-glucose.
• It exists in two forms: amylose (unbranched) and amylopectin (branched).
• Amylopectin has 1,6 linkages, making it branched.
• Plants use starch to store glucose.

Glycogen

• Glycogen is a branched polymer of α-glucose similar to amylopectin.
• It's a primary glucose storage form in animals.
• Mammals store glucose in the form of glycogen in the liver and muscle cells.

Glycoproteins

• Glycoproteins are polypeptides with attached carbohydrates, components of plasma membranes.
• They are crucial for cell-cell recognition.
• ABO antigens on red blood cells are examples.

Lipids-Fats

• Lipids are key components of cell membranes.
• They're made of carbon, oxygen, and hydrogen.
• Lipids are insoluble in water (hydrophobic) but dissolve in non-polar solvents.
• Types include triglycerides, phospholipids, and steroids.

Triglycerides

• Triglycerides are formed from three fatty acids and one glycerol molecule.
• Fats and oils are triglycerides.
• They're useful for energy storage.

Fatty Acids

• Fatty Acids contain a long hydrocarbon chain and a carboxyl group. This group is a COOH.
• Important feature of a fatty acid

Glycerol

• Glycerol is a three-carbon chain molecule with three hydroxyl groups (-OH) bonded to it.

Types of Fatty Acids

• Saturated Fatty Acids: All carbon atoms in the chains are linked by single covalent bonds.
• Unsaturated Fatty Acids: Contain one or more double bonds between carbon atoms; can be monounsaturated (one double bond) or polyunsaturated (two or more double bonds).
  • Cis unsaturated: Hydrogens are on the same side of the double bond
  • Trans unsaturated: Hydrogens are on the opposite side of the double bond.

Phospholipids

• Similar to triglycerides, but with one phosphate group replacing a fatty acid.
• They have a polar hydrophilic head and hydrophobic tails.
• Major components of cell membranes.

Steroids

• Steroids have a unique four-ring structure.
• Cholesterol, progesterone, estrogen, and testosterone are examples.

Lipids and Health

• Fats and oils (lipids) and glycogen are important energy stores.
• Plants store energy as starch or oil in their seeds.
• In humans, glycogen is stored in the liver and muscles. Fat is stored in adipose tissue..
• Lipids release more energy per gram than carbohydrates.
• Trans fats are often industrially produced and are now banned in many places.
• A high intake of saturated fatty acids has been correlated with heart disease although this relationship is complex and some studies show no correlation between saturated fat and heart disease.

Este cuestionario explora las características y tipos de carbohidratos, incluyendo azúcares simples y complejos. Aprenderás sobre su composición química, fuentes alimenticias y su clasificación. Ideal para estudiantes de nutrición y biología.