Exam1 Cell Organelles

Nucleus

Contains most of the cell’s DNA and helps control cell activities through gene expression.

Nucleolus

The dense area inside the nucleus that makes rRNA and assembles ribosomal subunits.

Nuclear envelope

The double membrane surrounding the nucleus.

Nuclear pores

Openings that regulate movement into and out of the nucleus.

Chromatin

DNA together with its associated proteins.

Ribosomes

Structures made of RNA and protein that read mRNA and join amino acids to make proteins.

Rough ER

Membranes with attached ribosomes. Makes proteins for secretion and membranes.

Smooth ER

Membranes without ribosomes. Involved in lipid and carbohydrate metabolism.

Golgi apparatus

Modifies, sorts and packages proteins and other molecules. Think: cell post office.

Lysosomes

Enzyme-filled sacs that digest waste, foreign material and worn-out cell parts.

Peroxisomes

Organelles involved in oxidation and detoxification, including breaking down hydrogen peroxide.

Mitochondria

Organelles that produce ATP during cellular respiration. They have two membranes and their own DNA.

Cytosol versus cytoplasm

Cytosol is the fluid. Cytoplasm includes the cytosol and organelles outside the nucleus.

Cytoskeleton

A protein framework that supports cell shape and helps movement. Includes microtubules, intermediate filaments and actin.

Centrosome and centrioles

The centrosome organizes microtubules. In animal cells, it contains paired centrioles.

Vesicles

Small membrane sacs that store or transport materials.