AP Biology: Unit 2 Complete Guide

Compartmentalization

The defining characteristic of eukaryotic cells, allowing incompatible metabolic processes to occur simultaneously within the same cell.

The Nucleus

Houses the genome (DNA) and directs protein synthesis via mRNA.

Ribosomes

Non-membrane-bound complexes of rRNA and protein that perform translation (protein synthesis).

Endoplasmic Reticulum (ER)

A network of membranes that includes Rough ER (modifies proteins) and Smooth ER (lipid synthesis and detoxification).

Golgi Complex

A structure made of flattened membrane sacs (cisternae) that modifies and ships proteins.

Lysosomes

Organelles that perform intracellular digestion using hydrolytic enzymes.

Vacuoles

Membrane-bound sacs within the cell that store nutrients and waste products.

Mitochondria

Powerhouses of the cell that produce ATP through cellular respiration.

Chloroplast

Organelles in plants and algae where photosynthesis occurs.

Surface Area to Volume Ratio (SA:V)

An important factor that determines metabolic efficiency; high ratios are preferable for cell function.

Passive Transport

Movement of substances across a membrane without the use of ATP, following the concentration gradient.

Active Transport

Movement of substances against a concentration gradient, requiring energy (ATP).

Osmoregulation

The process of maintaining water balance in a cell or organism.

Tonicity

The relative concentration of solute in a solution compared to the concentration of solute in a cell.

Endosymbiotic Theory

A theory explaining the origin of eukaryotic cells, stating they evolved from prokaryotic organisms.

Aquaporins

Channel proteins that facilitate the rapid movement of water across the cell membrane.

Hydrolytic Enzymes

Enzymes found in lysosomes that are responsible for breaking down waste materials and cellular debris.

Glycosylation

The process of adding carbohydrate tags to proteins for sorting and recognition.

High Water Potential

The condition where water moves from regions of high water potential (lower solute concentration) to low water potential (higher solute concentration).

Phagocytosis

A form of endocytosis in which large particles are engulfed by the cell.

Pinocytosis

A form of endocytosis in which the cell takes in extracellular fluid.

Receptor-Mediated Endocytosis

A process where cells capture specific molecules through the binding of those molecules to receptors on the cell surface.

Hydrophobic Core

The inner region of the plasma membrane that repels polar molecules and ions.

Ionization Constant (i)

A measure indicating the number of particles into which a solute dissociates in solution, used in calculating solute potential.

Pressure Potential ($ ext{Ψ}_p$)

The physical pressure exerted by the cell wall in a plant cell, contributing to the overall water potential.

Solute Potential ($ ext{Ψ}_s$)

The potential of water to move by osmosis due to the concentration of solutes; always negative.