Biomolecules: Carbohydrates and Simple Sugars

Biomolecules

• Essential molecules that make up living things
• Also known as biochemicals
• Thousands of biomolecules are categorized into four groups: Carbohydrates, Proteins, Lipids, and Nucleic Acids

Carbohydrates

• The simplest biomolecules made up of Carbon, Hydrogen, and Oxygen
• General formula: (CHO)n, where n represents the number of carbon atoms
• Often referred to as sugars

Simple Sugars

• A type of carbohydrate
• Break down quickly in the body, providing a quick burst of energy, often referred to as a "sugar rush"
• Simple sugars come in many forms but the most important and simplest is Glucose (C6H12O6)
• Used in cells and created by photosynthesis.
• Other simple sugars include: Fructose, Sucrose, Galactose, and Mannose
• Simple sugars are highly soluble in water.
• They easily pass through membranes, making them easily accessible as an instant source of energy in the cell.
• Can serve as building blocks for complex sugars.
• Used to construct other organic molecules.

Monosaccharides

• Simple sugars with only one sugar unit
• Identified by the number of carbon atoms they are made of
• Examples:
  • Triose (3 Carbon atoms)
  • Pentose (5 Carbon atoms)
  • Hexose ( 6 Carbon atoms)

Complex Carbohydrates

• Chainlike molecules called polymers that include repeating units called monomers
• The monomers are called monosaccharides
• Polymers are formed from covalently-bonded monomers
• Covalent bonds form when one monomer loses a hydroxyl group (OH) and another loses a hydrogen atom through a dehydration or condensation reaction
• The bond formed is called a glycosidic linkage
• Examples include Starch, Cellulose

Human Nutrition

• Humans obtain Carbon, Hydrogen and Oxygen from food, water and air
• Carbohydrates are obtained mostly from plants but are found in all organisms
• 90% of human body weight comes from these three elements
• One gram of carbohydrates provides 4 food calories or 16 kJ of energy

Sources of Energy

• Carbohydrates provide energy for:
  • Cell growth
  • Cell division
  • Metabolism
  • Repair
  • Maintenance of the body

Biomolecules

• Humans need three elements for survival: Carbon, Hydrogen, and Oxygen.
• More than 90% of a human's body weight comes from these three elements.
• Biomolecules, also called biochemicals, are the molecules that make up living things.
• They can be very large and come in thousands of different types.
• There are four categories of biomolecules: carbohydrates, proteins, lipids, and nucleic acids.
• We get these elements from the food we eat, the water we drink, and the air we breathe.

Carbohydrates

• Carbohydrates are the simplest biomolecules, usually containing Carbon, Hydrogen, and Oxygen.
• The general formula for carbohydrates is CnH2mOm.
• They are made up of repeating units called monomers.
• These monomers form covalent bonds through dehydration or condensation reactions.
• A glycosidic linkage occurs when one monomer loses a hydroxyl group and the other loses a hydrogen atom.
• There are two types of carbohydrates: simple and complex.

Simple Carbohydrates (Sugars)

• Simple carbohydrates are quickly broken down in the body.
• They are made up of one sugar unit (monosaccharide) or two sugar units (disaccharide).
• Glucose is the most important simple sugar, having the formula C6H12O6.
• Sucrose has the formula C12H22O11.
• They provide a quick burst of energy (a sugar rush).
• Good sources of simple carbohydrates include fruits, vegetables, and dairy products.

Monosaccharides

• Monosaccharides contain only one sugar unit.
• These are simple sugars with one sugar unit.
• They are identified based on the number of carbon atoms they contain.
• Examples of monosaccharides include:
  • Triose (3 carbon atoms)
  • Pentose (5 carbon atoms)
  • Hexoses (6 carbon atoms)
• Glucose is also known as dextrose, fructose, galactose, and mannose.

Complex Carbohydrates

• Complex carbohydrates are made up of many sugar units linked together in long chains.
• They are broken down more slowly in the body and provide a sustained source of energy.
• Examples of complex carbohydrates include:
  • Starch
  • Cellulose

Role of Carbohydrates

• Carbohydrates provide a source of energy to the body.
• They are used in cell growth, cell division, metabolism, repair, and maintenance of the body.
• Carbohydrates serve as building blocks in the formation of complex sugars.
• They are starting materials for the construction of other organic molecules.