Cell Structure

Plasma Membrane

• Phospholipid bilayer

• provides support and protection to the cell; controls what goes in and out of the cell.

Nucleus

Contains DNA.

Nuclear Envelope

• Double membrane

• continuous with the endoplasmic reticulum

• regulates entry and exit of molecules.

Nuclear Pores

• Gaps that allow passage of molecules.

Nucleoplasm

• Similar to cytoplasm but for the nucleus.

Chromatin

• Unwound chromosomes that form DNA when the cell is not dividing.

Nucleolus

• Part of the nucleus that makes ribosomes.

Mitochondria

• Site where aerobic respiration takes place.

Double Membrane

• Controls what goes in and out of the mitochondria.

Cristae

• In mitochondria

• Provides a large surface area for the attachment of enzymes for respiration.

Matrix

Contains proteins, lipids, DNA, and ribosomes within mitochondria.

Rough Endoplasmic Reticulum

• Has ribosomes on the outer surface

• synthesizes proteins and glycoproteins

• provides a large surface area and pathway for transport of materials.

Smooth Endoplasmic Reticulum

• Synthesizes, stores, and transports lipids and carbohydrates.

Golgi Apparatus

• Stacks of cisternae with vesicles; modifies, labels, and transports proteins.

Lysosome

• Contains lysozyme and digestive enzymes

• isolates lysozyme and hydrolyzes bacterial cell walls.

Ribosomes

Made of ribosomal DNA; involved in protein synthesis.

Cell Wall

• Supports the cell and provides structure; made of cellulose; microfibrils prevent bursting.

• has plasmodesmata (pore) & middle lamella

Chloroplast

• Site of photosynthesis.

• has grana (stacks of thylakoids) where first stage of photosynthesis takes place

• has stroma (like cytoplasm) - 2nd site of photosynthesis

Vacuole

Fluid-filled sac surrounded by tonoplast; supports plants by maintaining turgor pressure.