Biomolecules and Bioenergetics – Vocabulary Flashcards

Vocabulary flashcards covering major biomolecules, their classifications, and bioenergetics concepts from the lecture notes.

Biomolecules

Molecules building blocks of life that occur inside living organisms and perform essential biological functions (carbohydrates, lipids, nucleic acids, amino acids, proteins).

Carbohydrates

Biomolecules composed of carbon, hydrogen, and oxygen in fixed ratios; primary energy source for cells.

Monosaccharide

The simplest carbohydrate; a single sugar unit that does not dissociate on hydrolysis.

Disaccharide

A carbohydrate formed from two monosaccharide units; dissociates on hydrolysis (e.g., sucrose, lactose).

Polysaccharide

Carbohydrates with many monosaccharide units (>10); examples include starch and cellulose.

Aldose

Carbohydrate containing an aldehyde group.

Ketose

Carbohydrate containing a ketone group.

Glucose

A hexose monosaccharide; a primary source of cellular energy.

Lipids

Hydrophobic organic compounds (fats, oils) that are insoluble in water and important for energy storage and membranes.

Triglycerides

Esters of glycerol with three fatty acids; main form of dietary fat and energy storage.

Waxes

Esters of fatty acids with alcohols other than glycerol.

Phospholipids

Lipids with fatty acids, glycerol, and phosphate; major components of cell membranes.

Glycolipids

Lipids that contain carbohydrate groups; present in cell membranes.

Nucleic Acids

Biomacromolecules made of nucleotides; DNA and RNA; store and transmit genetic information.

Nucleotide

Sugar + phosphate group + nitrogenous base; the building block of nucleic acids.

Pentose Sugar

Five-carbon sugar in nucleotides; ribose in RNA, deoxyribose in DNA.

Nitrogenous Base

Nitrogen-containing bases; purines (adenine, guanine) and pyrimidines (cytosine, thymine, uracil).

DNA

Deoxyribonucleic acid; double-stranded genetic material using deoxyribose; base pairs A-T and G-C.

RNA

Ribonucleic acid; usually single-stranded; ribose sugar; bases A, G, C, Uracil (U); includes mRNA, tRNA, rRNA.

Amino Acids

Organic molecules with an amino group and a carboxyl group; monomers of proteins; have side chains (R).

Essential Amino Acids

Amino acids not synthesized by humans; must be obtained from diet (e.g., tryptophan, leucine, phenylalanine, threonine, lysine).

Non-essential Amino Acids

Amino acids synthesized by the body; examples include glycine, serine, glutamate.

Proteins

High molecular weight biomolecules made of amino acids; functions include structure, enzymes, antibodies, transport.

Peptide Bond

Covent bond between amino acids linking the amino group of one to the carboxyl group of another.

Globular Proteins

Water-soluble, usually spherical proteins (e.g., albumin).

Fibrous Proteins

Water-insoluble proteins with elongated, fibrous structures (e.g., collagen, keratin).

Conjugated Proteins

Proteins containing non-amino acid groups (glycoproteins, lipoproteins, nucleoproteins).

Derived Proteins

Proteins derived from simple or conjugated proteins through denaturation or degradation.

Secondary Structure

Local folding patterns of a protein (α-helix, β-pleated sheet) stabilized by hydrogen bonds.

Tertiary Structure

Three-dimensional shape of a single polypeptide chain.

Quaternary Structure

Arrangement of multiple polypeptide chains into a functional protein.

Bioenergetics

Study of energy production and consumption in living systems and metabolism.

Gibbs Free Energy (ΔG)

ΔG = ΔH − TΔS; energy available to do work; negative values indicate spontaneous processes.

Enthalpy (ΔH)

Heat content of a system at constant pressure; total internal energy plus PV term.

Entropy (ΔS)

Measure of disorder or randomness; positive ΔS indicates increased randomness.

Exergonic Reactions

Reactions that release energy; typically spontaneous with ΔG < 0.

Endergonic Reactions

Reactions that require energy input; ΔG > 0; non-spontaneous.

Redox Potential (E°)

Oxidation-reduction potential; tendency of a substance to gain electrons; related to ΔG.

ATP (Adenosine Triphosphate)

Energy currency of the cell; hydrolysis releases energy; can form ADP + Pi.

ADP (Adenosine Diphosphate)

Product of ATP hydrolysis; can be re-phosphorylated to ATP.

CAMP (Cyclic AMP)

Secondary messenger produced by activation of adenylyl cyclase; mediates cellular signaling.