Lecture 7: Nucleic Acids and Lipids Vocabulary

Vocabulary flashcards covering key definitions and biological concepts regarding nucleic acids and lipids from Lecture 7.

Gene

A unit of inheritance that stores hereditary information and consists of nucleic acids.

Nucleic Acids

Biological macromolecules, specifically Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA), that store and transmit hereditary information.

Gene Expression

The process by which DNA directs messenger RNA (mRNA) synthesis and, through mRNA, controls protein synthesis.

Polynucleotides

Polymers composed of nucleotide monomers that form nucleic acid molecules.

Nucleotide

The monomer of a polynucleotide, composed of a nitrogenous base, a pentose sugar, and one or more phosphate groups.

Nucleoside

The portion of a nucleotide that lacks a phosphate group, consisting only of a nitrogenous base and a sugar.

Pyrimidines

A family of nitrogenous bases with a single six-membered ring, comprising cytosine, thymine, and uracil.

Purines

A family of nitrogenous bases with a six-membered ring fused to a five-membered ring, comprising adenine and guanine.

Deoxyribose

The pentose sugar present in DNA nucleotides.

Ribose

The pentose sugar present in RNA nucleotides.

Phosphodiester Linkage

A phosphate group linkage that joins the sugars of adjacent nucleotides to construct a polynucleotide backbone.

Antiparallel

The structural arrangement of a DNA double helix where the two sugar-phosphate backbones run in opposite $5' \rightarrow 3'$ directions.

Complementary Base Pairing

The specific hydrogen bonding arrangement between nitrogenous bases in nucleic acids (adenine with thymine or uracil, and guanine with cytosine).

Lipids

A diverse class of large biological molecules composed mostly of nonpolar hydrocarbon chains that mix poorly with water and are not true polymers.

Glycerol

A three-carbon alcohol with a hydroxyl group attached to each carbon, serving as a building block for fats.

Fatty Acid

A long carbon skeleton attached to a carboxyl group, serving as a component of fats and phospholipids.

Triacylglycerol

A fat molecule, also called a triglyceride, formed by joining three fatty acid molecules to a single glycerol via ester linkages.

Saturated Fatty Acids

Fatty acids containing no double bonds, possessing the maximum number of hydrogen atoms possible.

Unsaturated Fatty Acids

Fatty acids that contain one or more double bonds in their carbon skeleton.

Hydrogenation

The chemical process of converting unsaturated fats into saturated fats by adding hydrogen.

Trans Fats

Fats created during hydrogenation that contain trans double bonds and may contribute to cardiovascular disease.

Essential Fatty Acids

Unsaturated fatty acids, such as omega-3 fatty acids, that cannot be synthesized by the human body and must be acquired through the diet.

Adipose Cells

Specialized mammalian cells that store long-term food reserves of fat, cushion vital organs, and insulate the body.

Phospholipids

Molecules consisting of two hydrophobic fatty acid tails and a hydrophilic phosphate head attached to glycerol, which self-assemble into bilayers in cell membranes.

Steroids

Lipids characterized by a carbon skeleton composed of four fused rings.

Cholesterol

A type of steroid found in animal cell membranes that acts as a precursor for synthesized steroid hormones like estradiol, cortisol, testosterone, aldosterone, and progesterone.