Chapter 5: The Structure and Function of Large Biological Molecules

Vocabulary flashcards for reviewing macromolecules, carbohydrates, lipids, proteins, and nucleic acids.

Macromolecules

Large molecules, including carbohydrates, lipids, proteins, and nucleic acids.

Polymers

Long molecules consisting of many similar or identical building blocks linked by covalent bonds (excluding lipids).

Monomer

The smaller molecules that can be linked together to form polymers.

Enzymes

Specialized macromolecules that speed up chemical reactions.

Dehydration Synthesis

A reaction in which two molecules are covalently bonded to each other with the removal of a water molecule.

Hydrolysis

A process that requires water to break chemical bonds.

Carbohydrates

Sugars and polymers of sugars, classified as monosaccharides, disaccharides, and polysaccharides.

Monosaccharide

A single sugar molecule; the simplest type of carbohydrate.

Disaccharide

Two monosaccharides joined by a glycosidic linkage.

Polysaccharides

Macromolecules, polymers with many glycosidic linkages.

Glycosidic Linkage

A linkage made of a covalent bond formed between two monosaccharides by a dehydration reaction

Starch

Plants use this as a storage polysaccharide.

Glycogen

Animals use this as a storage polysaccharide.

Cellulose

A structural polysaccharide found in plant cell walls.

Chitin

A structural polysaccharide that is part of the exoskeleton in some animals and in cell walls of some fungi.

Lipids

A class of biological molecules that mix poorly with water; includes fats, phospholipids, and steroids.

Fat

Glycerol + fatty acids; also known as triacylglycerol/triglyceride.

Glycerol

A 3-carbon alcohol with -OH group

Fatty acid

A long carbon skeleton with carboxyl group on one end (the non-polar C-H bonds make it hydrophobic).

Triacylglycerol/Triglyceride

A fat molecule with three fatty acids attached to one glycerol by an ester bond.

Ester linkage

A bond between a hydrocarbon and a carboxyl group.

Saturated fats

Fats thought to contribute to atherosclerosis.

Trans fats

Fats that may contribute more than saturated fats to atherosclerosis; banned in some countries and US cities.

Phospholipids

Lipids similar to fat, but with only two fatty acids attached to glycerol and a phosphate group bound to the third carbon of glycerol; major constituent of cell membranes.

Steroids

A carbon skeleton consisting of four fused rings; includes cholesterol.

Cholesterol

A type of steroid and a crucial molecule in animals; a common component of animal cell membranes and a precursor for hormones.

Proteins

Structurally sophisticated molecules that account for more than 50% of the dry mass of cells; composed of combinations of 20 amino acids; biologically functional polypeptide(s).

Polypeptide

Polymer of amino acids.

Amino acids

An organic molecule with an amino and carboxyl group; side chains determine unique characteristics of each amino acids.

Denaturation

Weak Chemical bonds are broken and cause protein to lose its shape and become inactivated

Chaperonins

Protein molecules that assist in proper folding of other proteins.

Gene

Discrete unit of inheritance coding for an amino acid sequence of a polypeptide.

Nucleic acids

Polymers made of monomers/nucleotides; examples are DNA and RNA.

DNA

Provides directions for its own replication; directs RNA synthesis; through RNA controls protein synthesis, gene expression.

RNA

Codes for mRNA to direct polypeptide production; mRNA interacts with the cell’s protein- synthesizing machinery to produce polypeptides.

Polynucleotides

Composed of nucleotides.

Nucleotides

3 parts: 5-carbon sugar (pentose), nitrogenous base, and one or more phosphate groups.

Nucleoside

Nucleotide minus phosphate groups.

Adjacent nucleotides

Joined by phosphodiester bonds (phosphate group that links the sugars of 2 nucleotides).

Genomics

analysis of large sets of genes or comparing whole genomes

Proteomics

analysis of large sets of proteins