Plant Physiology - Plant Cells (Lecture 3)

Bio 332 - CSUMB 2025

What are the Characteristics of Plant Cells?

cell wall, chloroplasts, vacuole

Cell Wall

differentiated into primary and secondary types; composed of cellulose, hemicellulose, pectin, and lignin; essential for maintaining cell shape, providing protection, and enabling terrestrial adaptation

Middle Lamella

pectin-rich layer acting as adhesive to bind adjacent cells

Chloroplast

organelles responsible for photosynthesis; involved in ATP and sugar synthesis; derived from an endosymbiotic event

Vacuole

can occupy up to 95% of the cell’s volume; functions include storage, solute regulation, and maintaining turgor pressure

Plasma Membrane

acts as a selective barrier based on the fluid mosaic model controls molecular transport

Aquaporins

protein channels facilitating rapid water transport, and potentially CO₂ movement

Plasmodesmata

channels connecting cells to allow simplistic transport and intercellular communication

Recent Developments

live-cell imaging of cellulose synthesis reveals that cell walls are dynamic structures rather than static entities