Carbon, Lipids, and Carbohydrates Lecture Flashcards

Vocabulary practice flashcards covering the properties of carbon, types and functions of lipids, and the structural differences between carbohydrate polymers based on the lecture material.

Carbon

An element that can form four covalent bonds, making large, complex molecules possible in living organisms.

Hydrocarbons

Chains composed of repeating nonpolar covalent bonds that do not mix with water.

True polymers

Macromolecules consisting of repeating monomer structures that are identical or similar, such as carbohydrates, proteins, and nucleic acids.

Lipids

A class of macromolecules that are not true polymers because they lack common repeating structures, but are grouped by their hydrophobic nature.

Fats (Triglycerides)

Molecules composed of three fatty acid tails linked together by a hydrophilic glycerol molecule, primarily used for energy storage.

Saturated fat

A lipid with the maximal number of hydrogens bonded to the carbon chain, making it more viscous and solid-like at room temperature.

Unsaturated fat

A lipid containing one or more double-bonded carbons, which creates a kink in the structure and makes it less viscous.

Kink

A bend in an unsaturated fatty acid structure caused by double bonds, affecting the ability of the molecules to pack together.

Cholesterol

An important steroid that acts as a 'spacer' between fatty acids in cell membranes to regulate fluidity and prevent freezing.

Steroids

Lipid molecules, such as estradiol and testosterone, characterized by a carbon skeleton consisting of four fused rings.

Carbohydrates

A macromolecule group that serves as the cellular energy source for all life and includes sugars like glucose.

Monosaccharides

The simplest sugar monomers, which include glucose, fructose, and galactose.

Disaccharides

Carbohydrates formed by two monosaccharides, such as lactose, maltose, and sucrose.

Lactose

A disaccharide composed of the monomers glucose and galactose.

Maltose

A disaccharide composed of two glucose monomers.

Glycogen

A polysaccharide composed of alpha-glucose monomers used for energy storage in animals.

Starch

A polysaccharide composed of alpha-glucose monomers used for energy storage in plants.

Cellulose

A structural polysaccharide made of beta-glucose monomers that is non-digestible to humans and known as dietary fiber.

Alpha ($\alpha$) linkages

Bonds in glucose polymers where the hydroxyl ($OH$) group and oxygen are facing the same direction, which humans can break down.

Beta ($\beta$) linkages

Bonds in glucose polymers where the hydroxyl group and oxygen are facing different directions, which humans and most animals cannot break down.

Dietary fibers

Non-digestible carbohydrates that stimulate mucus production in the GI lining and slow down sugar uptake to improve digestion.

Fat energy content

The amount of energy stored in lipids, measured at $37\,kJ\,g^{-1}$, making it more efficient for energy storage in mammals.

Carbohydrate energy content

The amount of energy stored in carbohydrates, measured at $17\,kJ\,g^{-1}$, used primarily as an immediate energy source.

Isotopes

Atoms of the same element that have the same number of protons but different numbers of neutrons, such as $^{12}C$ and $^{14}C$.

Hydrogen bonds

A charge-based attraction between a partially positive hydrogen atom and a partially negative atom like fluorine, oxygen, or nitrogen.