Cell Organelles

Plasma membrane

The phospholipid bilayer that encloses the cell and regulates what substances move in and out

Nucleus (plural = nuclei)

Membrane-bound organelle that houses the cell's DNA and controls gene expression and cell activity

Nuclear envelope

Double membrane surrounding the nucleus, containing pores that regulate movement of materials in and out

Chromatin

The combination of DNA and proteins found in the nucleus; condenses into chromosomes during cell division

Nucleolus (plural = nucleoli)

Dense structure within the nucleus responsible for producing ribosomal RNA and assembling ribosomes

Cytoplasm

The gel-like substance filling the cell, containing the organelles suspended between the nucleus and plasma membrane

Ribosomes

Small structures made of RNA and protein that synthesize proteins by translating mRNA

Rough Endoplasmic Reticulum

Network of membranes studded with ribosomes; synthesizes and folds proteins, especially those for secretion

Smooth Endoplasmic Reticulum

Network of membranes lacking ribosomes; synthesizes lipids, detoxifies substances, and stores calcium

Golgi Apparatus

Stack of flattened membranes that modifies, sorts, and packages proteins and lipids for transport

Secretory Vesicles

Membrane-bound sacs that transport and release proteins or other molecules out of the cell via exocytosis

Mitochondria

Double-membraned organelle that generates ATP through cellular respiration

Lysosomes

Membrane-bound organelles containing digestive enzymes that break down waste, debris, and worn-out cell parts

Peroxisomes

Membrane-bound organelles that break down fatty acids and detoxify harmful substances using enzymes like catalase