LO1-LO3 Review: Carbohydrates and Synthesis of Biological Polymers

Question-and-answer flashcards covering dehydration synthesis and hydrolysis, carbohydrate structure (monosaccharides, disaccharides, polysaccharides), glycosidic linkages (alpha/beta), energy storage vs structure, and cell identity.

What is dehydration synthesis?

A reaction where monomers join to form a polymer with the release of a water molecule (condensation).

What is hydrolysis?

A reaction that breaks polymers into monomers with water consumption.

Monosaccharides are named by what?

The number of carbons they contain.

What bond holds carbohydrates together and can be α or β in glycosidic linkages?

Glycosidic bonds.

What structure results from alpha vs beta glycosidic linkages in polysaccharides?

Alpha linkages form coiled polysaccharides; beta glycosidic linkages form strong sheets.

Where is energy stored in starch and glycogen?

Between the C-C and C-H bonds in the polymer.

What is the primary function of cellulose?

Structural; dietary fiber; found in plant cell walls and not easily digested.

Where do carbohydrates attach in cells, and what is the function of the attached oligosaccharides?

Attach to proteins in the plasma membranes and extracellular matrix; oligosaccharides function in signaling and cell identity.

What are the four major macromolecule classes?

Carbohydrates, lipids, proteins, nucleic acids.

What is the general empirical formula for carbohydrates?

CnH2nOn (often written as (CH2O)n).

Monosaccharides are usually how many carbons?

3 to 7 carbons.

What suffix do monosaccharides usually have?

-ose.

What distinguishes ketose from aldose in monosaccharides?

Internal carbonyl indicates ketose; external carbonyl indicates aldose.

Name the common carbon-length categories of monosaccharides.

Trioses (3), pentoses (5), hexoses (6).

What determines alpha vs beta in ring forms of monosaccharides?

The orientation at the anomeric carbon (ring closure) determines alpha or beta.

Which monosaccharides form five-membered rings and which form six-membered rings in solution?

Fructose and ribose form five-membered rings; glucose forms a six-membered ring.

How are disaccharides formed, and what bond links them?

Two monosaccharides are joined by a dehydration reaction via a glycosidic bond; water is released (e.g., glucose + fructose → sucrose).

Provide an example of a disaccharide formed from glucose and fructose.

Sucrose.

Describe polysaccharides in terms of monomer linkage, branching, and molecular weight.

Polysaccharides are long chains of monosaccharides joined by glycosidic linkages; may be branched or unbranched; can contain multiple monosaccharide types; often MW > 10,000 daltons.

What are the three major functions of polysaccharides?

Energy storage (alpha linkages), structural support (beta linkages), and cell identity.

Name polysaccharides with alpha glycosidic linkages and their roles.

Starch (amylose and amylopectin) in plants and glycogen in animals; coils that store energy.

Name polysaccharides with beta glycosidic linkages and their roles.

Cellulose in plant cell walls and chitin in animal exoskeletons and fungal cell walls; provide structure and support.

What is the function of oligosaccharides attached to proteins in membranes and the extracellular matrix?

They contribute to cell identity and signaling (e.g., ABO blood typing).