Cell Biology and Biological Macromolecules

A comprehensive set of vocabulary flashcards covering cell theory, organelle functions, the cytoskeleton, membrane transport mechanisms, and basic biological chemistry based on the lecture transcript.

Cell theory

The unifying foundation of cell biology stating that all organisms are composed of one or more cells and that cells arise only by division of preexisting cells.

Peptidoglycan

A substance consisting of carbohydrate cross-linked with short peptides that makes up bacterial cell walls.

Nucleolus

A region of the nucleoplasm where rRNA is transcribed and ribosomes are assembled.

Rough ER (RER)

A site of protein synthesis studded with ribosomes that synthesize membrane proteins or proteins destined for export.

Smooth ER (SER)

A region of the endoplasmic reticulum involved in carbohydrate and lipid synthesis, detoxification, and the storage of $Ca^{2+}$.

Golgi apparatus

An organelle that receives vesicles from the ER, modifies and packages macromolecules, and transports them.

Lysosomes

Organelles containing digestive enzymes active at acid pH that break down macromolecules and recycle old organelle components.

Peroxisomes

A type of microbody containing enzymes used to oxidize fats.

Cristae

The extensively folded layers of the inner membrane of mitochondria where metabolism occurs to produce ATP.

Endosymbiont theory

The proposal that mitochondria and chloroplasts were once prokaryotes that were engulfed by another cell.

Actin filaments

Also known as microfilaments; long, thin polymers involved in cellular movement and cell crawling.

Microtubules

Hollow structures that move materials within a cell and compose the 9+2 structure of eukaryotic flagella.

Centrosomes

Microtubule-organizing centers that help assemble the nuclear division apparatus of animal cells.

Kinesin and dynein

Two motor proteins that move vesicles along microtubules like a train on a track.

Extracellular matrix (ECM)

A structure secreted by animal cells, primarily composed of glycoproteins.

Gap junctions

Communicating junctions in animals that allow the passage of small molecules between cells.

Plasmodesmata

Connections in plants that penetrate the cell wall to connect adjacent cells.

Dehydration reaction

A chemical reaction that forms biological polymers by the elimination of water ($H$ and $OH$) from two monomers.

Hydrolysis

The process of breaking down biological polymers into monomers by the addition of water.

Chaperone proteins

Proteins, such as heat shock proteins, that assist in the proper folding of other proteins.

Denaturation

The unfolding of a protein's tertiary structure, usually destroying its function.

Triglycerides

Lipids consisting of three fatty acids connected to a glycerol molecule.

Fluid mosaic model

A model of membrane structure featuring proteins embedded in and floating in or on a fluid lipid bilayer.

Transmembrane domain

A membrane-spanning region of a protein, usually composed of hydrophobic amino acids arranged in $\alpha$ helices.

Aquaporins

Water channels that facilitate the diffusion of water across membranes.

Sodium-potassium pump

An active transport mechanism that moves three $Na^{+}$ out of the cell and two $K^{+}$ into the cell using ATP.

Receptor-mediated endocytosis

A type of bulk transport where specific molecules bind to receptors on the cell membrane before entering the cell in a vesicle.

pH formula

$$pH = -\log[H^{+}]$$

Photosynthesis Equation

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$$