Biological Macromolecules - Vocabulary Flashcards

A set of vocabulary flashcards covering the key concepts from the lecture notes on biological macromolecules, including carbohydrates, lipids, proteins, nucleic acids, and their structures and roles.

Biological macromolecules

Large, life-sustaining molecules built from smaller organic subunits.

Monomer

A small unit that can join with others to form a polymer (e.g., amino acids, sugars).

Dehydration synthesis

Forming a larger molecule by removing water to create a covalent bond.

Hydrolysis

Using water to break a large molecule into smaller pieces.

Monosaccharides

Simple sugars; basic units of carbohydrates (e.g., glucose, fructose, galactose).

Glucose

A common monosaccharide and important energy source.

Fructose

A monosaccharide found in fruit; part of sucrose.

Galactose

A monosaccharide that is part of lactose.

Isomer

Compounds with the same formula but different structure; e.g., glucose, fructose, galactose are structural isomers.

Disaccharides

Two monosaccharides linked by a glycosidic bond (e.g., sucrose, lactose, maltose).

Sucrose

Disaccharide composed of glucose and fructose.

Lactose

Disaccharide composed of galactose and glucose.

Maltose

Disaccharide composed of two glucose units.

Glycosidic linkage

Covalent bond joining two monosaccharides.

Polysaccharides

Long chains of monosaccharides; may be branched; high molecular weight (e.g., starch, cellulose, glycogen, chitin).

Starch

Plant storage polysaccharide (amylose/amylopectin).

Cellulose

Plant cell wall polysaccharide; humans cannot digest it; dietary fiber.

Glycogen

Animal storage polysaccharide in liver and muscles.

Chitin

Polysaccharide in insect exoskeletons and fungal cell walls; contains nitrogen.

Waxes

Long-chain fatty acids esterified to long-chain alcohols; hydrophobic protective layer.

Fats and oils (triglycerides)

Glycerol backbone with three fatty acids; formed by ester linkages; release 3 H2O during formation.

Fatty acids

Carboxyl group with long hydrocarbon chain; can be saturated or unsaturated.

Saturated fatty acids

No carbon–carbon double bonds; pack tightly; solids at room temperature; potential CV risk in excess.

Monounsaturated fatty acids

Contain one C=C double bond; typically liquids are oils but can be solid saturated in some cases; generally healthier than saturated fats.

Polyunsaturated fatty acids

More than one C=C double bond; usually liquids; includes omega-3/omega-6 fatty acids.

Omega-3 fatty acids

Essential polyunsaturated fats (e.g., alpha-linolenic acid); beneficial for heart and brain health.

Omega-6 fatty acids

Essential polyunsaturated fats; important in diet and metabolism.

Phospholipids

Lipids with two fatty acids and a phosphate-containing head; form the cell membrane bilayer; amphipathic.

Phospholipid bilayer

Two-layer membrane with hydrophobic tails inward and hydrophilic heads outward.

Steroids

Hydrophobic lipids with four fused carbon rings; include cholesterol and hormones.

Cholesterol

Steroid important for membrane structure and precursor to hormones and bile salts.

Proteins

Most abundant organic molecules with diverse functions (regulatory, structural, transport, enzymes, toxins).

Amino acids

Monomers of proteins; contain an amino group, a carboxyl group, a central carbon, and a variable R group.

Peptide bond

Covalent bond linking amino acids via dehydration synthesis.

Primary structure

Unique sequence of amino acids in a polypeptide.

Secondary structure

Local folding of the polypeptide into α-helix or β-pleated sheet via backbone hydrogen bonds.

α-helix

Right-handed helix stabilized by hydrogen bonds along the backbone.

β-pleated sheet

Polypeptide segments held together by hydrogen bonds forming a sheet-like structure.

Tertiary structure

Three-dimensional shape of a protein due to interactions among R-groups.

Disulfide bridge

Covalent bond between cysteine residues stabilizing tertiary structure.

Quaternary structure

Association of two or more polypeptide subunits into a functional protein.

Sickle cell anemia

Disease caused by a single amino acid substitution (glutamic acid to valine) in hemoglobin beta chain.

Nucleic acids

Molecules that store and transfer genetic information; DNA and RNA.

Nucleotides

Monomers of nucleic acids; composed of a sugar, a phosphate, and a nitrogenous base.

DNA double helix

Two antiparallel strands with sugar–phosphate backbone on the outside and bases inside; base pairing A–T and C–G.

Antiparallel orientation

Two DNA strands run in opposite directions (5'→3' and 3'→5').

Base pairing in DNA

Adenine pairs with thymine; cytosine pairs with guanine via hydrogen bonds.

RNA types

Messenger RNA (mRNA), Transfer RNA (tRNA), and Ribosomal RNA (rRNA).

mRNA

Messenger RNA; blueprint for protein; leaves nucleus; read by ribosome.

tRNA

Transfer RNA; delivers specific amino acids to growing polypeptide; has an anticodon.

rRNA

Ribosomal RNA; component of ribosomes and has catalytic activity in protein synthesis.

Transcription

Process of copying DNA into RNA; occurs in the nucleus (in eukaryotes).

Translation

Process by which ribosomes synthesize protein from mRNA using tRNA and amino acids.

Chromatin

DNA-Protien complex found in nucleus; packaging form of DNA.

Chromosomes

Condensed form of chromatin visible during cell division.