Organic Compounds, The Cell, and Metabolism – Chapters 3 & 4

Vocabulary flashcards covering organic macromolecules, cell structures, metabolic processes, the cell cycle, and tumor terminology from Chapters 3 and 4 lecture notes.

Organic macromolecule

Large carbon-based compound; four classes: carbohydrates, lipids, proteins, nucleic acids.

Carbohydrate

Energy-providing macromolecule made of monosaccharides.

Monosaccharide

Single sugar unit such as glucose, fructose, ribose.

Disaccharide

Two monosaccharides joined together; e.g., sucrose, lactose.

Polysaccharide

Many monosaccharides linked for energy storage; e.g., glycogen, starch.

Glycogen

Animal storage form of glucose found mainly in liver and muscle.

Starch

Plant storage polysaccharide of glucose.

Cellulose

Plant structural polysaccharide; dietary fiber for humans.

Lipid

Energy-rich macromolecule built from fatty acids and cholesterol.

Fatty acid

Hydrocarbon chain with carboxyl group; basic lipid building block.

Triglyceride

Stored-energy fat molecule composed of glycerol + 3 fatty acids.

Phospholipid

Amphipathic lipid forming the cell membrane bilayer.

Steroid

Lipid-derived hormone built from cholesterol (e.g., estrogen).

Protein

Structural and functional macromolecule made of amino acids.

Amino acid

Protein building block; 20 common types.

Peptide bond

Covalent linkage between two amino acids.

Polypeptide

Chain of many amino acids; folds into a protein.

Essential amino acid

Amino acid the body cannot synthesize; must be eaten.

Non-essential amino acid

Amino acid the body can synthesize internally.

Nucleic acid

Information-storing macromolecule (DNA or RNA) built from nucleotides.

Nucleotide

Monomer of nucleic acids; sugar + phosphate + nitrogen base.

DNA

Double-stranded nucleic acid that stores genetic instructions.

RNA

Single-stranded nucleic acid that helps build proteins.

Plasma membrane

Semipermeable phospholipid bilayer enclosing the cell.

Cytoplasm

Cellular material between nucleus and membrane; cytosol + organelles.

Organelle

Membrane-bound "little organ" with a specific cell function.

Ribosome

Organelle that synthesizes proteins; free or on rough ER.

Endoplasmic reticulum (ER)

Network of membranes; rough ER modifies proteins, smooth ER makes lipids & glycogen.

Rough ER

ER studded with ribosomes; folds and modifies new proteins.

Smooth ER

ER lacking ribosomes; synthesizes lipids, steroids, glycogen.

Golgi apparatus

"UPS center" that packages, labels, and ships proteins via exocytosis.

Mitochondrion

"Powerhouse" organelle making ATP by aerobic respiration.

Lysosome

Enzyme-filled vesicle that digests debris, bacteria, old organelles.

Cytoskeleton

Protein network giving cell shape, movement, and mitotic spindle.

Microvilli

Membrane projections that increase surface area for absorption.

Cilia

Short hair-like extensions that move substances across cell surfaces.

Flagellum

Long whip-like structure enabling sperm motility.

Anabolism

Metabolic "build-up" reactions requiring energy.

Catabolism

Metabolic "break-down" reactions releasing energy.

ATP

Cell’s energy currency produced mainly in mitochondria.

Aerobic respiration

O₂-dependent pathway in mitochondria producing lots of ATP and CO₂.

Anaerobic respiration

O₂-independent glycolysis in cytoplasm yielding little ATP and lactic acid.

Lactic acid

End-product of anaerobic glucose breakdown; sent to liver.

Ketoacid (ketone)

Waste produced when lipids are catabolized for energy.

Ammonia

Toxic by-product of protein catabolism.

Urea

Less-toxic compound the liver forms from ammonia; excreted by kidneys.

G₁ phase

Interphase stage of normal growth and preparation for DNA synthesis.

S phase

Interphase stage where DNA is replicated.

G₂ phase

Interphase stage synthesizing substances needed for mitosis.

Mitosis

Nuclear division producing two identical daughter cells (46 chromosomes each).

Stem cell

Undifferentiated cell capable of repeated mitosis and specialization.

Benign tumor

Non-invasive mass of cells from excessive mitosis.

Malignant tumor

Cancerous growth that invades tissues and may metastasize.

Metastasis

Spread of malignant cells to distant body sites.