Module 1: Biomolecules in Living Things – Lesson 1.1 Biomolecules

Vocabulary flashcards covering key biomolecules concepts, cell structure, and viruses from Lesson 1.1.

Biomolecules

Molecules that make up living beings, including carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrates

Hydrogen- and oxygen-containing organic molecules (CH2O)n; monomer is the monosaccharide; energy source and roles in digestion and structure.

Monosaccharide

Simple sugar; the basic building block of carbohydrates.

Lipids

Hydrophobic organic compounds insoluble in water; monomer is glycerol + fatty acids; includes fats, oils, phospholipids, steroids.

Fatty acid

Long hydrocarbon chain with a carboxyl group; component of lipids; saturation affects fat properties.

Glycerol

Alcohol backbone that bonds to fatty acids to form triglycerides and other lipids.

Protein

Biomolecule built from amino acids; functions include enzymes, antibodies, movement, structure.

Amino acid

Monomer of proteins; contains amino group, carboxyl group, and variable side chain (R).

Nucleotide

Monomer of nucleic acids; consists of a sugar, phosphate, and nitrogenous base.

Nucleic acids

Polymers of nucleotides (DNA and RNA) that store and transmit genetic information.

DNA

Deoxyribonucleic acid; double-stranded molecule storing genetic information; bases: A, T, C, G.

RNA

Ribonucleic acid; single-stranded molecule involved in protein synthesis; bases: A, U, C, G.

Covalent bond

Bond formed by sharing electron pairs between atoms; strong, foundational in biomolecules.

Bond energy

Energy required to break a covalent bond

Hydrogen bond

Weak bond between a hydrogen attached to an electronegative atom and another electronegative atom; key in biomolecular structure.

Van der Waals interactions

Weak noncovalent attractions from fluctuating electron clouds; includes dipole–dipole and dispersion forces.

Ionic interactions

Electrostatic attractions between oppositely charged groups or ions; can involve permanent or induced dipoles.

Hydrophobic interactions

Nonpolar regions aggregate in water to maximize entropy and drive folding and assembly.

Functional group

Chemically reactive group of atoms in organic molecules that defines chemical properties; examples include OH, C=O, COOH, NH2, SH, and phosphate.

Hydroxyl group

-OH; polar and water-soluble; forms hydrogen bonds (example: ethanol).

Carbonyl group

C=O; carbonyls can be aldehydes (terminal) or ketones (internal) in a molecule.

Aldehyde

Carbonyl group at the end of the carbon skeleton.

Ketone

Carbonyl group within the carbon skeleton.

Carboxyl group

-COOH; weak acid; can donate H+ to form carboxylate; acidic properties in solution.

Amino group

-NH2; acts as a base; can accept protons in solution.

Amide

Derivative of carboxylic acid where the –OH is replaced by an –NH2 group (example: ethanamide).

Ester

Derivative of carboxylic acid with -COO- linkage; formed by dehydration synthesis in polymerization.

Sulfhydryl group

-SH; can form disulfide bridges; important for stabilizing protein structure (cysteine).

Phosphate group

-PO4; carries negative charges; energy transfer (ATP) and backbone of DNA/RNA.

ATP

Adenosine triphosphate; primary energy-transferring molecule in cells.

Macromolecule

Large biomolecule built from building blocks; exhibits directionality and informational content; often 3D in structure.

Directionality

Sense or direction in polymer growth (e.g., proteins from N- to C-terminus; nucleic acids 5' to 3').

Three-dimensional architecture

Biomolecules have characteristic 3D shapes that determine function and interactions.

Weak forces

Noncovalent interactions that stabilize biomolecules: hydrogen bonds, ionic interactions, van der Waals, hydrophobic effects.

Glycoprotein

Protein with carbohydrate attached; components of membranes and signaling.

Glycolipid

Lipid with carbohydrate attached; membrane component involved in signaling and recognition.

Cholesterol

Sterol that modulates membrane fluidity and stability.

Phospholipid bilayer

Two-layer membrane made of phospholipids; hydrophilic heads outward; hydrophobic tails inward; basis of membranes.

Membrane proteins

Proteins in the membrane that form channels/transporters, receptors, enzymes; integral or peripheral.

Cytoskeleton

Network of filaments (microfilaments, microtubules, intermediate filaments) providing support and transport within the cell.

Cilia and flagella

Motile structures for movement; cilia are short, flagella are whip-like; composed of microtubules.

Nucleus

Double-membrane organelle containing chromosomes; control center of the cell.

Nucleolus

Nuclear substructure where ribosomal RNA is synthesized and ribosomes begin to form.

Nuclear envelope

Double membrane surrounding the nucleus with nuclear pores.

Nuclear pore

Protein-lined openings in the nuclear envelope that regulate transport between nucleus and cytoplasm.

Endoplasmic reticulum (ER)

Membrane network; rough ER has ribosomes for protein synthesis; smooth ER synthesizes lipids and carbohydrates.

Rough endoplasmic reticulum

ER with ribosomes attached; synthesizes and modifies proteins.

Golgi apparatus

Packaging and shipping center of the cell; proteins and lipids are modified, sorted, and sent in vesicles.

Lysosome

Digestive organelle with hydrolytic enzymes; breaks down waste and old cell parts.

Mitochondrion

Powerhouse of the cell; double-membrane organelle where cellular respiration occurs, producing ATP.

Chloroplast

Organelle in plant cells that conducts photosynthesis; contains chlorophyll and starch storage; derived from photosynthetic bacteria.

Vacuole

Membrane-bound storage sac; large central vacuole in plant cells stores water, nutrients, and wastes.

Bacteriophage

Virus that infects bacteria.

TMV (Tobacco Mosaic Virus)

Virus with a helical capsid and RNA at the center; rod-like structure.

Adenovirus

Virus that can cause pink eye and the common cold; contains double-stranded DNA.

Enveloped virus

Virus surrounded by a lipid envelope derived from the host membrane; common in animal viruses.

Prion

Proteinaceous infectious particle with no nucleic acid; causes diseases like mad-cow disease.

Viroid

Small circular RNA without a protein coat; infects plants (and some other hosts).

Virus life cycle

Attachment to host cell, entry, replication, assembly of new viruses, and release; some viruses can lie dormant.

Genome

Complete set of genetic material in a cell or organism.

Surface markers / receptor sites

Virus recognition depends on matching viral surface markers to cellular receptors.

Base pairing

Hydrogen-bonded pairing of nucleotides: A with T (DNA) and C with G; A with U (RNA) and C with G (RNA).

Chromosome

DNA-protein complex that carries hereditary information; organized during cell division.

Ribosome

Ribonucleoprotein particle that carries out protein synthesis; composed of RNA and protein.

Dehydration synthesis

Condensation reaction that forms polymers by removing water.

Genetic information flow

DNA stores information, is transcribed into RNA, which is translated into proteins.

Biomolecules

Molecules that make up living beings, including carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrates

Hydrogen- and oxygen-containing organic molecules (CH2O)n; monomer is the monosaccharide; energy source and roles in digestion and structure.

Monosaccharide

Simple sugar; the basic building block of carbohydrates.

Disaccharide

Carbohydrate formed from two monosaccharides joined by dehydration synthesis.

Polysaccharide

Complex carbohydrate formed from many monosaccharides; examples include starch, glycogen, and cellulose.

Lipids

Hydrophobic organic compounds insoluble in water; monomer is glycerol + fatty acids; includes fats, oils, phospholipids, steroids.

Fatty acid

Long hydrocarbon chain with a carboxyl group; component of lipids; saturation affects fat properties.

Glycerol

Alcohol backbone that bonds to fatty acids to form triglycerides and other lipids.

Protein

Biomolecule built from amino acids; functions include enzymes, antibodies, movement, structure.

Amino acid

Monomer of proteins; contains amino group, carboxyl group, and variable side chain (R).

Peptide bond

Covalent bond that links amino acids together to form polypeptides.

Enzyme

Proteins that act as biological catalysts, speeding up biochemical reactions.

Nucleotide

Monomer of nucleic acids; consists of a sugar, phosphate, and nitrogenous base.

Nucleic acids

Polymers of nucleotides (DNA and RNA) that store and transmit genetic information.

DNA

Deoxyribonucleic acid; double-stranded molecule storing genetic information; bases: A, T, C, G.

RNA

Ribonucleic acid; single-stranded molecule involved in protein synthesis; bases: A, U, C, G.

Phosphodiester bond

Covalent bond that links nucleotides together to form polynucleotide chains (DNA/RNA).

Covalent bond

Covalent bond formed by sharing electron pairs between atoms; strong, foundational in biomolecules.

Bond energy

Energy required to break a covalent bond; examples include H–H 436, C–H 414, C–C 343, C–O 351 kJ/mol.

Hydrogen bond

Weak bond between a hydrogen attached to an electronegative atom and another electronegative atom; key in biomolecular structure.

Van der Waals interactions

Weak noncovalent attractions from fluctuating electron clouds; includes dipole–dipole and dispersion forces.

Ionic interactions

Electrostatic attractions between oppositely charged groups or ions; can involve permanent or induced dipoles.

Hydrophobic interactions

Nonpolar regions aggregate in water to maximize entropy and drive folding and assembly.

Functional group

Chemically reactive group of atoms in organic molecules that defines chemical properties; examples include OH, C=O, COOH, NH2, SH, and phosphate.

Hydroxyl group

-OH; polar and water-soluble; forms hydrogen bonds (example: ethanol).

Carbonyl group

C=O; carbonyls can be aldehydes (terminal) or ketones (internal) in a molecule.

Aldehyde

Carbonyl group at the end of the carbon skeleton.

Ketone

Carbonyl group within the carbon skeleton.

Carboxyl group

-COOH; weak acid; can donate H+ to form carboxylate; acidic properties in solution.

Amino group

-NH2; acts as a base; can accept protons in solution.

Amide

Derivative of carboxylic acid where the –OH is replaced by an –NH2 group (example: ethanamide).

Ester

Derivative of carboxylic acid with -COO- linkage; formed by dehydration synthesis in polymerization.

Sulfhydryl group

-SH; can form disulfide bridges; important for stabilizing protein structure (cysteine).

Phosphate group

-PO4; carries negative charges; energy transfer (ATP) and backbone of DNA/RNA.