Carbohydrates and Lipids- Bio

Vocabulary-style flashcards covering key concepts about carbohydrates and lipids from the lecture notes.

Macromolecule

A large, complex molecule; the four major classes of life’s organic molecules are carbohydrates, lipids, proteins, and nucleic acids.

Polymer

A long molecule made of repeating building blocks (monomers) bonded together.

Monomer

A single building block that polymers are built from.

Dehydration reaction (condensation)

A synthesis reaction where two monomers join and water is removed.

Hydrolysis

A breakdown reaction where polymers are disassembled into monomers by adding water.

Carbohydrates

Sugars and their polymers; serve as fuel and building material for cells.

Monosaccharide

A simple sugar; often CH2O; glucose is a common example; can form ring structures in solution.

Glucose

Most common monosaccharide; C6H12O6; hexose; forms rings in aqueous solutions.

Disaccharide

Two monosaccharides joined by a glycosidic linkage (e.g., sucrose).

Sucrose

Table sugar; disaccharide composed of glucose and fructose.

Glycosidic linkage

Covalent bond formed between sugar molecules via a dehydration reaction.

Polysaccharide

Polymers of sugars; can be for storage or structural roles.

Starch

Storage polysaccharide in plants consisting entirely of glucose; amylose is the simplest form.

Amylose

The simplest form of starch; a linear polymer of glucose.

Glycogen

Storage polysaccharide in animals; stored mainly in liver and muscles; hydrolyzed to release glucose.

Cellulose

Structural polysaccharide in plant cell walls; glucose monomers with beta linkages forming tough fibrils.

Beta glycosidic linkage

The beta form of glycosidic bond found in cellulose, contributing to its rigidity.

Chitin

Structural polysaccharide in arthropod exoskeletons and fungal cell walls; subunit is N-acetyl glucosamine.

Lipids

Not true polymers; hydrophobic molecules that include fats, phospholipids, and steroids.

Fats (triglycerides)

Energy-storage lipids composed of glycerol + three fatty acids; formed by condensation with ester linkages.

Fatty acids

Carboxyl-containing hydrocarbon chains; part of triglycerides and phospholipids.

Ester linkage

Bond formed between glycerol and fatty acids during triglyceride synthesis.

Saturated fatty acid

Fatty acid with maximum hydrogen atoms and no double bonds; typically solid at room temperature.

Unsaturated fatty acid

Fatty acid with one or more double bonds; typically liquid at room temperature.

Trans fatty acid

Unsaturated fats that have been hydrogenated to produce trans double bonds; associated with health risks.

Omega-3 fatty acid

Essential unsaturated fatty acid with the first double bond at the third carbon from the end; protective for heart health.

Phospholipid

Lipid with a glycerol backbone, a phosphate head (hydrophilic) and two fatty acid tails (hydrophobic); amphipathic.

Phospholipid bilayer

Two-layer arrangement of phospholipids that forms the cell membrane; tails inward, heads outward.

Steroid

Lipids with a carbon skeleton of four fused rings; includes cholesterol and various hormones.

Cholesterol

Steroid component of animal cell membranes and precursor to other steroids; high blood levels can be linked to cardiovascular disease.