Introductions, monosaccharide structure

What are carbohydrates

Carbohydrates are metabolic precursors of most biomolecules.

What does the breakdown of carbohydrates result in

The breakdown of carbohydrates provides energy to sustain animal life. Energy from the sun is stored as chemical energy in the form of carbohydrates.

Describe the structural functions of carbohydrates

• Ribose and deoxyribose are vital components of RNA and DNA, the fundamental molecules of life.

• Polysaccharides (carbohydrates) are the major structural parts of cell walls of bacteria and plants.

what is cellulose

Cellulose is the major constituent of plant cell walls. It is the most abundant class of biomolecule in the biosphere.

Name 4 variable biophysical properties

• chitin

• hyaluronates

• chondroitans

• dermatan sulfate

What is chitin

Chitin is the main structural component of crustacean, insect, and spider exoskeletons.

What are hyaluronates

Hyaluronates are important for the vitreous humour of eyes, synovial fluid, and cartilage.

Where are chondroitans found

Chondroitans and collagen are found in tendons, cartilage, and connective tissue.

What is dermatan sulfate

Dermatan sulfate is a component of the extracellular skin matrix.

What are glycoproteins

Glycoproteins are proteins with a covalent attachment to a carbohydrate.

Give examples of natural proteins that are glycoproteins

Structural proteins, enzymes, membrane receptors, transport proteins, immunoglobulins and others.

What are glycoproteins a vital part of

Glycoproteins on a cell surface are a vital part of recognition (blood antigenic determinants), and cell adhesion (e.g. the binding of sperm to eggs).

What is molecular recognition

Cell surface glycoproteins are recognition agents by which cells interact with other cells, and invading organisms. (viruses and bacteria).

The carbohydrate portion of glycoproteins are vital in infection of the cell. Viruses use the carbohydrate part of a glycoprotein to bind to a cell.

What does the term carbohydrate derive from

The term carbohydrate derives from glucose, the first simple carbohydrate isolated. With a molecular formula of C6H12O6 glucose was initially thought to be a hydrate of carbon C6H2O6

What is carbohydrate composition

Carbohydrate composition is [C·(H₂O)]_n, where n ≥ 3.

Describe ways in which a carbohydrate can be described

A carbohydrate can be described as one of the following:

• a polyhdroxy aldehyde

• a polyhydroxy ketone

• a compound that hydrolyses to give a polyhydroxy aldehyde

• a compound that hydrolyses to give a polyhydroxy ketone.

Name two types of classifications of carbohydrates

Carbohydrates are classified as simple or complex

What are simple carbohydrates

Simple carbohydrates are monomers that cannot be hydrolysed to smaller carbohydrates. These are called monosaccharides or just sugars.

Give examples of simple monosaccharides

Glucose, fructose, galactose, ribose

What are complex carbohydrates

complex carbohydrates consist of two or more monosaccharides joined together by covalent bonds (glycosidic linkages).

Name examples of complex carbohydrates

• disaccharides

• trisaccharides

• oligosaccharides

• polysaccharides

What do disaccharides hydrolyse into

Disaccharides hydrolyse to give two monosaccharides.

e.g. sucrose → glucose + fructose

What to trisaccharides hydrolyse into

Trisaccharides hydrolyse to give three monosaccharides.

e.g. raffinose → galactose + glucose + fructose

How many monosaccharide units do oligosaccharides contain

Oligosaccharides contain 2-10 monosaccaride units.

How many monosaccharide units do polysaccharides contain

Polysaccharides contain a large number of monosaccharides

e.g. cellulose ~ 3000 glucose monomers

What are monosaccharides

Monosaccharides are aldehyde or ketone derivatives of straight chain polyhydroxy alcohols, containing at least three carbon atoms.

Such substances cannot be hydrolysed to form simpler sacchardies.