Biomolecules and Biological Compounds of Life

Vocabulary flashcards covering the characteristics, classifications, and functions of carbohydrates, lipids, proteins, and nucleic acids as detailed in the lecture notes.

Biomolecules

Molecules of compounds needed for life, including carbohydrates, fats, proteins, and nucleic acids.

Inorganic Molecules

Molecules that do not contain carbon along with hydrogen and occur in aqueous phases as ions and salts, such as minerals, gases like $CO_2$, and water ($H_2O$).

Organic Molecules

Molecules containing carbon and hydrogen together, occurring in both aqueous and non-aqueous phases, such as carbohydrates, lipids, proteins, and nucleic acids.

Micromolecules

Small organic molecules with low molecular weight and simple structure, such as simple sugars and amino acids.

Macromolecules

Large organic molecules with high molecular weight and complex structure, such as polysaccharides, proteins, and nucleic acids.

Monomers

Simple molecules and smaller units from which larger molecules are made, characterized by low molecular weight.

Polymers

Complex molecules made from a large number of monomers joined together, characterized by high molecular weight.

Condensation reaction

A chemical reaction involving the joining of two molecules together by the removal of a water molecule.

Hydrolysis

A chemical reaction in which a chemical bond is broken by the addition of a water molecule.

Glycosidic bond

A covalent bond formed in carbohydrates by a condensation reaction to join monosaccharides into polysaccharides.

Peptide bond

A covalent bond that links amino acids together to form polypeptide chains in proteins.

Phosphodiester bond

A strong covalent bond that joins nucleotides together to form the sugar-phosphate backbone of DNA and RNA.

Carbohydrates

A group of polyhydroxy aldehydes or ketones containing carbon, hydrogen, and oxygen, with the general formula $C_n(H_2O)_n$.

Monosaccharides

Basic units of carbohydrates that cannot be further hydrolyzed, with the general formula $C_n H_{2n} O_n$, consisting of 3 to 7 carbon atoms.

Aldoses

Monosaccharides that contain an aldehyde group ($CHO$), such as glucose, galactose, and ribose.

Ketoses

Monosaccharides that contain a ketone group ($C=O$), such as fructose, ribulose, and xylulose.

Isomer

Molecules that have the same molecular formula but different orientations or arrangements of atoms.

Pyranose

A hexagonal ring structure in monosaccharides consisting of 5 carbon atoms and 1 oxygen atom.

Furanose

A pentagonal ring structure in monosaccharides consisting of 4 carbon atoms and 1 oxygen atom.

Alpha ($\alpha$) Glucose

A structural isomer of glucose where the hydroxyl ($OH$) group on carbon 1 is located below the ring.

Beta ($\beta$) Glucose

A structural isomer of glucose where the hydroxyl ($OH$) group on carbon 1 is located above the ring.

Reducing sugar

Carbohydrates with a free carbonyl group that can donate electrons and reduce metallic ions, such as glucose, lactose, and maltose.

Non-reducing sugar

Carbohydrates without a free carbonyl group that cannot reduce metallic ions, such as sucrose.

Oligosaccharides

Carbohydrates formed by the condensation of 2 to 10 monosaccharides, including disaccharides, trisaccharides, and tetrasaccharides.

Disaccharides

Double sugars made of 2 monosaccharide units held by a glycosidic bond, with the general formula $C_{12}H_{22}O_{11}$. Examples include maltose, lactose, and sucrose.

Lactose

A disaccharide known as milk sugar, made of one glucose and one galactose molecule.

Sucrose

A disaccharide known as cane or table sugar, made of one glucose and one fructose molecule.

Polysaccharides

Polymers of 10 or more monosaccharides joined by glycosidic bonds, with the general formula $(C_6H_{10}O_5)_n$.

Homopolysaccharides

Polysaccharides made up of only one type of monosaccharide unit, such as glycogen, starch, and cellulose.

Heteropolysaccharides

Polysaccharides made up of two or more types of monosaccharide units, such as hyaluronic acid, heparin, and pectin.

Starch

An important storage carbohydrate in plants consisting of amylase and amylopectin, which gives a dark blue color with iodine.

Glycogen

The storage form of carbohydrates in animal tissue, found in the liver and muscles, which gives a red color with iodine.

Cellulose

A fibrous, water-insoluble structural homopolysaccharide found in plant cell walls, linked by $\beta-1,4$ glycosidic bonds.

Chitin

A structural homopolysaccharide found in the exoskeleton of insects, crabs, and lobsters.

Lipids

A diverse group of water-insoluble, hydrophobic organic compounds made of carbon, hydrogen, and oxygen, such as fats, oils, and waxes.

Ester Bond

The bond formed during a condensation reaction between the hydroxyl group of glycerol and the carboxyl group of a fatty acid.

Triglycerides

Esters formed by one molecule of glycerol and three molecules of long-chain fatty acids.

Amphipathic compound

A molecule having both hydrophobic (non-polar) and hydrophilic (polar) parts, such as a fatty acid.

Saturated Fatty Acids

Fatty acids with no double bonds between carbon atoms that are mostly solid at room temperature, such as palmitic acid ($C=16$).

Unsaturated Fatty Acids

Fatty acids with one or more double bonds in the hydrocarbon chain that are liquid at room temperature.

Phospholipids

Compound lipids containing a phosphate group, glycerol, and fatty acids, formed by replacing one fatty acid of a triglyceride.

Cholesterol

A derived lipid found in animal membranes, used to manufacture steroid hormones, Vitamin D, and bile acids.

Proteins

Complex macromolecules, or polypeptides, made of carbon, hydrogen, oxygen, nitrogen, and sulfur ($C, H, O, N, S$).

Amino Acid

The building block of proteins, consisting of a central carbon, an amino group, a carboxyl group, and a variable R-group.

Essential Amino Acids

A group of 9 amino acids that the human body cannot produce and must be consumed through diet.

Primary Structure

The simplest level of protein structure, consisting of the unique linear sequence of amino acids linked by peptide bonds.

Secondary Structure

Local folded structures within a polypeptide chain, specifically the alpha ($\alpha$) helix and beta ($\beta$) pleated sheet, held by hydrogen bonds.

Tertiary Structure

The three-dimensional folding pattern of a protein maintained by ionic bonds, hydrogen bonds, disulfide bonds, and hydrophobic interactions.

Quaternary Structure

Protein structure resulting from the packing together of multiple polypeptide chains (subunits), such as in haemoglobin (4 subunits) or collagen (3 subunits).

Denaturation

The process where high temperature or extreme pH disrupts the 3D structure and bonds of a protein, destroying its functionality.

Globular Proteins

Spherical or rounded proteins that are usually soluble in water and involved in metabolic reactions, such as enzymes and haemoglobin.

Fibrous Proteins

Long, thread-like proteins that are strong, stable, and generally insoluble, providing structural support, such as keratin and collagen.

Nucleic Acid

Polymers functioning as genetic material with the ability to store information and self-copy; they exist as DNA and RNA.

Nucleotide

The monomeric unit of nucleic acids, composed of a nitrogenous base, a pentose sugar (ribose or deoxyribose), and a phosphate group.

Purines

Nitrogenous bases with a double ring structure, consisting of Adenine ($A$) and Guanine ($G$).

Pyrimidines

Nitrogenous bases with a single ring structure, consisting of Thymine ($T$), Cytosine ($C$), and Uracil ($U$).

ATP (Adenosine triphosphate)

A nucleotide consisting of adenine, ribose, and three phosphate groups, used as an energy source.

Chargaff's rule

States that in double-stranded DNA, the amount of adenine equals thymine ($A=T$) and guanine equals cytosine ($G=C$).

Messenger RNA (mRNA)

RNA that carries the complementary genetic code from DNA during transcription in triplets called codons.

Ribosomal RNA (rRNA)

The most abundant type of RNA (80%), found in ribosomal subunits and involved in protein synthesis.

Transfer RNA (tRNA)

Smallest RNA molecules shaped like a clover leaf that carry amino acids to the ribosome during translation, matching anticodons with mRNA codons.