Lesson 3 - Biological Molecules

Vocabulary flashcards covering key terms and concepts from Lesson 3 - Biological Molecules.

Macromolecules

Large biological molecules composed of thousands of covalently bonded atoms.

Polymer

A long molecule consisting of many similar or identical building blocks linked by covalent bonds.

Monomer

The repeating units that serve as the building blocks of a polymer.

Enzymes

Specialized macromolecules, usually proteins, that speed up chemical reactions.

Dehydration reaction

A chemical reaction in which two molecules become covalently bonded to each other with the loss of a water molecule.

Hydrolysis

A chemical reaction that breaks bonds between monomers by the addition of a water molecule.

Carbohydrate

A biological molecule serving as a fuel and structural material, including sugars and polymers of sugars.

Monosaccharide

The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides.

Polysaccharide

A polymer of many monosaccharides, formed by dehydration reactions.

Glycosidic linkage

A covalent bond formed between two monosaccharides by a dehydration reaction.

Starch

A storage polysaccharide in plants, consisting entirely of glucose monomers.

Glycogen

An extensively branched glucose storage polysaccharide found in the liver and muscle of animals.

Cellulose

A structural polysaccharide of plant cell walls, consisting of glucose monomers joined by $\beta$ glycosidic linkages.

Chitin

A structural polysaccharide found in many fungal cell walls and in the exoskeletons of arthropods.

Lipid

Any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly with water.

Fatty acid

A carboxylic acid with a long carbon chain, varying in length and in the number and location of double bonds.

Triacylglycerol

A lipid consisting of three fatty acids linked to one glycerol molecule.

Sat/Ungat fatty acid

Saturated and unsaturated fatty acids, categorized by the absence or presence of double bonds in their hydrocarbon chains.

Phospholipid

A lipid made up of glycerol joined to two fatty acids and a phosphate group, forming a hydrophobic tail and hydrophilic head.

Steroid

A type of lipid characterized by a carbon skeleton consisting of four fused rings.

Protein

A biologically functional molecule consisting of one or more polypeptides folded into a specific three-dimensional structure.

Amino acid

An organic molecule possessing both a carboxyl group and an amino group, serving as the monomer of proteins.

Polypeptide

A polymer of many amino acids linked together by peptide bonds.

Peptide bond

The covalent bond between the carboxyl group of one amino acid and the amino group of another, formed by a dehydration reaction.

Primary structure

The specific, linear sequence of amino acids making up a polypeptide chain.

Secondary structure

Regions of repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bonding.

Tertiary structure

The overall three-dimensional shape of a polypeptide resulting from interactions between the side chains (R groups) of amino acids.

Quaternary structure

The overall protein structure that results from the aggregation of two or more polypeptide subunits.

Denaturation Gene

Concepts referring to denaturation, where a protein loses its native shape and function, and genes, which encode the primary sequence of proteins.

Nucleic acid

A polymer consisting of many nucleotide monomers, serving as a blueprint for proteins.

Nucleotide

The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and phosphate groups.

Pyrimidine

A nitrogenous base characterized by a six-membered ring, including cytosine, thymine, and uracil.

Purine

A nitrogenous base characterized by a six-membered ring fused to a five-membered ring, including adenine and guanine.

Deoxyribose/ribose

The five-carbon sugars found in nucleic acids, where deoxyribose is in DNA and ribose is in RNA.

Double helix

The cellular structure of native DNA, consisting of two adjacent polynucleotide strands wound into a spiral shape.

Antiparallel

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