Part ONE: Cell Structures and Processes - Notes (S7L2a): 2026 7th Grade Honors Biology

Nucleus

The control center of the cell that contains hereditary information (DNA) needed for cellular activities.

Mitochondria

Organelles known as the powerhouse of the cell, responsible for converting chemical energy from food into usable energy (ATP) through cellular respiration.

Chloroplasts

Organelles found in plant cells that capture light energy to drive photosynthesis, producing glucose and oxygen.

Cell Membrane

A semi-permeable lipid bilayer that regulates the movement of substances into and out of the cell, maintaining homeostasis.

Cell Wall

A rigid structure found outside the membrane in plants, fungi, and some bacteria that provides support and protection to the cell.

Cytoplasm

The jelly-like substance that fills the cell and surrounds organelles, serving as the site for many chemical reactions.

Vacuoles

Membrane-bound sacs used for storage of water, nutrients, or metabolic waste, critical for maintaining turgor pressure in plant cells.

Homeostasis

The process by which a cell maintains a stable internal environment despite external changes.