Biological Molecules: Carbohydrates, Lipids, and Digestive Chemistry

Vocabulary practice flashcards covering synthesis and hydrolysis reactions, carbohydrates, polysaccharides, digestive physiology, and lipid structures from the lecture.

Dehydration synthesis

The chemical process of bonding smaller molecules together to build a larger molecule by removing water.

Hydrolysis

The chemical reaction that breaks linkages between molecules, utilizing the meaning of lysis ("to break"), which occurs during digestion.

Polymer

A long molecule made by linking smaller individual molecules together, exemplified by fibrous materials like cotton or genetic molecules like DNA.

Monosaccharide

A single-unit sugar and cellular energy source that is small enough to be absorbed directly into the bloodstream without prior digestion.

Disaccharide

A carbohydrate composed of two linked smaller sugar molecules that is too large to enter the bloodstream until its linkage is broken.

Lactose

A disaccharide found in milk that stores short-term energy for offspring and requires the breaking of a single bond for digestion.

Maltose

A disaccharide produced through a dehydration reaction that links two glucose molecules together.

Amino acids

The molecular building blocks of proteins that are released by hydrolysis during digestion and linked together by dehydration synthesis to build body proteins.

Oligosaccharides

Carbohydrates with chain lengths intermediate between disaccharides and polysaccharides, found in foods like beans.

Starch

A digestible plant polysaccharide used to store energy, which begins chemical digestion in human saliva.

Tuber

An underground plant storage organ, such as a potato, that accumulates sugars produced during summer by linking them into starch.

Glycogen

A branched polysaccharide synthesized by animals to store extra glucose for long-term energy in the liver and muscles.

Cellulose

A structural plant polysaccharide, known nutritionally as fiber, that cannot be digested by any animal.

Coprophagy

The behavior of re-ingesting feces to absorb nutrients that were broken down by bacteria in the lower digestive tract, observed in animals such as rabbits.

Triglycerides

A category of lipids, also known as fats, that animals use as a concentrated, lightweight medium for long-term energy storage providing $9\,\text{calories}$ per gram.

Hydrophobic

The property of repelling water and failing to dissolve in water, characteristic of lipids and fats.

Saturated fat

A fat possessing only single bonds between carbons in its chain, allowing the molecules to pack tightly and remain solid at room and body temperature.

Unsaturated fat

A fat containing double bonds that create bends in the carbon chain, preventing tight packing and keeping the fat liquid at room and body temperature.