Cell Biology, Transport Mechanisms, and Biomolecules

Vocabulary flashcards covering cell cycle, mitosis, meiosis, membrane transport mechanisms, and organic biomolecules based on lecture notes.

Deoxyribonucleic acid (DNA)

The genetic material of cells, found in the nucleus, containing information that determines the structure of proteins.

Nucleic acids

Large organic molecules composed of C, H, O, N, and P, built from nucleotide subunits.

Nucleotide

The basic building block of nucleic acids, composed of a monosaccharide, a nitrogenous organic base, and a phosphate group.

Purines

Double-ringed nitrogenous organic bases found in nucleic acids, consisting of Guanine and Adenine.

Pyrimidines

Single-ringed nitrogenous organic bases found in nucleic acids, consisting of Cytosine, Thymine, and Uracil (RNA only).

Mitosis

Somatic cell division in which centrosomes play the central role.

Chromatin condensation

The process during prophase where chromatin condenses into double rod-shaped chromosomes with the involvement of the condensin complex.

Cytokinesis

The division of the cytoplasm of a cell, forming separate daughter cells.

Meiosis

Cell division that reduces the number of chromosomes from $2n$ (diploid) to $n$ (haploid), producing four haploid cells.

Gametes

Cells that participate in fertilization or the formation of new organisms, such as spermatocytes and oocytes.

Fluid Mosaic Model

A model describing the cell membrane structure as flexible and containing a mosaic of phospholipids, cholesterol, proteins, and carbohydrates.

Phospholipids

Molecules that form the basic double-layered structure (lipid bilayer) of cell membranes, containing a hydrophilic phosphate head and hydrophobic fatty acid tails.

Integral proteins

Plasma membrane proteins located within the lipid bilayer.

Peripheral proteins

Plasma membrane proteins situated outside the lipid bilayer, located on either the intracellular or extracellular side.

Glycocalyx

A carbohydrate coating on the extracellular side of the plasma membrane that provides protection, cushioning, cell recognition, and adhesion.

Diffusion

The movement of solutes from an area of higher concentration to an area of lower concentration in a solution.

Osmosis

The diffusion of water (solvent) across a selectively permeable membrane.

Osmotic pressure

The force required to prevent the movement of water by osmosis across a selectively permeable membrane.

Isotonic

Refers to a solution in which a cell neither shrinks nor swells.

Hypertonic

Refers to a solution that causes water to move out of the cell by osmosis, causing the cell to shrink.

Hypotonic

Refers to a solution that causes water to move into the cell by osmosis, causing the cell to swell.

Facilitated Diffusion

A carrier-mediated passive transport process moving substances across a membrane from higher to lower concentration without using metabolic energy.

Active transport

A mediated transport process requiring energy provided by ATP to move substances against their concentration gradient from lower to higher concentration.

Sodium-Potassium Pump

An active transport system that uses ATP breakdown to export $3\text{ Na}^+$ ions and import $2\text{ K}^+$ ions across the cell membrane.

Endocytosis

The bulk uptake of material through the plasma membrane by vesicle formation, including phagocytosis and pinocytosis.

Phagocytosis

A form of endocytosis meaning cell-eating, where solid particles are ingested via phagocytic vesicles.

Pinocytosis

A form of endocytosis meaning cell-drinking, where smaller vesicles ingest liquid containing dissolved molecules.

Exocytosis

The secretion of materials from a cell through vesicle formation.

Dehydration synthesis

A process, also called condensation reaction, where smaller subunit molecules are joined by covalent bonds to synthesize macromolecules, requiring energy.

Hydrolysis

The chemical breakdown of organic macromolecules using water, which releases energy.

Glucose

A common monosaccharide with the empirical formula $\text{C}_6\text{H}_{12}\text{O}_6$, created in photosynthesis and acting as a building block for starch, glycogen, and cellulose.

Sucrose

Common table sugar, a disaccharide composed of glucose and fructose subunits.

Lactose

Milk sugar, a disaccharide composed of glucose and galactose subunits.

Maltose

Malt sugar, a disaccharide composed of two glucose subunits.

Amylose

The simplest form of starch, composed of unbranched chains of hundreds of glucose subunits.

Amylopectins

A major plant storage starch composed of branched chains of hundreds of glucose subunits.

Glycogen

A highly branched polysaccharide that serves as the primary food reserve in vertebrate animals, prevalent in liver and muscle tissue.

Cellulose

An insoluble, linear polymer of glucose subunits that is indigestible to most organisms.

Chitin

The main component of arthropod exoskeletons, which can harden when combined with calcium carbonate.

Saturated fats

Fats containing a full complement of two hydrogen atoms for each carbon in their fatty acid chains.

Unsaturated fats

Fats (oils) containing fewer than two hydrogen atoms on one or more carbon atoms in their fatty acid chains, remaining liquid at room temperature.

Triglycerides

Lipids stored in adipose tissue consisting of three fatty acid chains attached to a glycerol backbone.

Polypeptide

A linear polymer composed of amino acid chains linked together by peptide bonds.

Zwitterion

A term meaning half-breed ion, describing an amino acid carrying both positive and negative charges.

Denaturation

A structural change rendering a protein nonfunctional when hydrogen bonds break due to high temperatures or pH changes.

Globular proteins

Water-soluble proteins with folded, ball-like structures, such as hemoglobin and pepsin.

Fibrous proteins

Water-insoluble proteins with elongated structures providing structural support, such as collagen, keratin, actin, and myosin.