Structure and Function of Large Biological Molecules

Vocabulary flashcards covering the structure, synthesis, decomposition, and functional categories of carbohydrates, lipids, proteins, and nucleic acids.

Macromolecules

Large molecules typically made of smaller subunits, categorized into four main types: carbohydrates, lipids, proteins, and nucleic acids.

Dehydration Synthesis

A chemical reaction that forms a polymer through the removal of an $H_2O$ molecule.

Hydrolysis

The breaking down of polymers into smaller subunits using water.

Monosaccharides

Simple sugars that serve as fuel and building materials of life, having the empirical formula $CH_2O$.

Glucose

A primary cellular fuel source for respiration and a building block for other macromolecules that exists in ring forms and can be stored as di- and polysaccharides.

Glycosidic Linkage

A covalent bond formed between two monosaccharides through dehydration synthesis, named by the carbons that bond.

Disaccharides

Molecules formed by two monosaccharides bonded together through dehydration synthesis, such as maltose, sucrose, and lactose.

Starch

A storage polysaccharide created by plants.

Glycogen

A storage polysaccharide synthesized by animals and stored in the liver and muscle.

Cellulose

The most abundant organic molecule on Earth; a structural polysaccharide made of straight, unbranched chains that forms tough plant cell walls.

Chitin

A structural polysaccharide found in exoskeletons.

Lipids

Diverse hydrophobic molecules that typically feature large regions of hydrocarbon chains.

Triacylglycerols (TAGs)

Fats, also known as triglycerides, composed of glycerol and fatty acid chains joined by ester linkages.

Saturated Fatty Acids

Fatty acids containing no double bonds in their hydrocarbon chains.

Unsaturated Fatty Acids

Fatty acids containing at least one double bond in their hydrocarbon chains.

Phospholipids

Lipid molecules that make up the plasma membrane.

Steroids

Lipids characterized by a four-carbon ring structure, which can function as hormones or cholesterol.

Enzymatic Proteins

Proteins whose function is the selective acceleration of chemical reactions, such as digestive enzymes catalyzing the hydrolysis of bonds in food molecules.

Defensive Proteins

Proteins whose function is protection against disease, such as antibodies that inactivate and help destroy viruses and bacteria.

Storage Proteins

Proteins whose function is the storage of amino acids, such as casein in milk.

Transport Proteins

Proteins whose function is the transport of substances, such as hemoglobin, the iron-containing protein of vertebrate blood.

Hormonal Proteins

Proteins that coordinate an organism's activities, such as insulin regulating blood sugar concentration by causing tissues to take up glucose.

Receptor Proteins

Proteins built into cell membranes that detect signaling molecules to enable the cell's response to chemical stimuli.

Contractile and Motor Proteins

Proteins whose primary function is movement.

Structural Proteins

Proteins whose function is support, such as keratin in hair, horns, feathers, and other skin appendages.

Peptide Bond

A bond formed by a dehydration reaction linking the carboxyl end of one amino acid to the amino end of an adjacent amino acid.

Primary Structure

The unique amino acid sequence of a protein, read in order from the N-terminus to the C-terminus.

Secondary Structure

Regions of a peptide chain that are coiled or folded into patterns, regulated by hydrogen bonding of atoms in the peptide backbone.

Tertiary Structure

The overall 3D shape of a protein, stabilized by interactions among R groups including hydrophobic interactions and disulfide bridges formed by cysteine.

Quaternary Structure

The overall protein structure resulting from the interaction of multiple polypeptide chains to form a functional protein.

Chaperonins

Protein folders that assist in folding polypeptide chains into their correct shapes.

Nucleotides

The monomers of nucleic acids, consisting of a nitrogenous base, a sugar (ribose or deoxyribose), and linked together by phosphodiester bonds.

Purines

A category of nitrogenous bases that includes adenine (A) and guanine (G).

Phosphodiester Bond

A covalent bond in the backbone of nucleic acids that links adjacent nucleotides together.