Cell Organelle

Eukaryotic Cells

Cells that have a nucleus; includes all plants, animals, fungi, and protists.

Organelles

Tiny organs; membrane-bound structures that each have specific functions for cell survival.

Plasma Membrane

Controls what gets in and out of the cell; maintains homeostasis through selective permeability.

Selective Permeability

The ability of a membrane to allow some substances to enter or leave while preventing others.

Cell Wall

Provides protection, support, and rigidity; found in plants, fungi, and bacteria but NOT animal cells.

Cellulose

The carbohydrate that makes up plant cell walls.

Chitin

The carbohydrate that makes up fungal cell walls.

Cytoplasm

The gel-like substance that holds organelles in place and is the site of most cellular reactions.

Fermentation

A cellular reaction that occurs in the cytoplasm.

Glycolysis

A cellular reaction that occurs in the cytoplasm and breaks down glucose.

Nucleus

The control center of the cell; contains the information needed to carry out life processes.

Chromatin

Uncondensed genetic material made of DNA found inside the nucleus.

Nuclear Envelope

The membrane surrounding the nucleus that controls what enters and exits through nuclear pores.

Nucleolus

The part of the nucleus that makes ribosome subunits.

Mitochondria

The powerhouse of the cell; site of cellular respiration where glucose is broken down to release energy.

Cristae

The inner folds of the mitochondria that increase surface area for cellular respiration.

Chloroplast

The organelle where photosynthesis occurs; found in plants and some protists.

Chlorophyll

The pigment inside chloroplasts that captures radiant/light energy.

Photosynthesis

The process that uses radiant energy to convert carbon dioxide and water into glucose.

Endoplasmic Reticulum (ER)

A network of tunnels that produces and transports molecules throughout the cell.

Rough ER

ER covered with ribosomes; produces and transports proteins to the Golgi apparatus.

Smooth ER

ER without ribosomes; makes and transports lipids.

Ribosomes

The site of protein synthesis; can be free-floating in the cytoplasm or attached to rough ER.

Golgi Apparatus

Flattened sacs that modify, package, and ship proteins made by the ER.

Vesicles

Small membrane-bound sacs that transport and package materials such as proteins.

Vacuoles

Fluid-filled sacs used for storage of water, salts, food, proteins, and carbohydrates.

Plant Vacuole

Plants typically have one large central vacuole.

Animal Vacuoles

Animals typically have many smaller vacuoles.

Contractile Vacuole

A special organelle found only in freshwater protists that removes excess water to maintain homeostasis.

Lysosomes

Vesicles containing digestive enzymes that break down food molecules, waste, and old cell parts.

Centriole

A barrel-shaped structure found in animal cells that organizes spindle fibers during cell division.

Cytoskeleton

Protein rods in the cytoplasm that help maintain cell shape and allow movement of the cell and materials inside it.

Microtubules

Protein structures that are part of the cytoskeleton and help maintain cell shape and movement.

Motile Structures

Cell structures that allow cells to move.

Cilia

Short, hair-like structures used for movement; found in organisms such as Paramecium.

Flagella

Long, tail-like structures that propel cells; human sperm use a flagellum to swim.

Pseudopod

An extension of cytoplasm that helps an amoeba move.

Plant Cells

Have a cell wall, cell membrane, one large central vacuole, and chloroplasts.

Animal Cells

Have a cell membrane but no cell wall; usually have smaller vacuoles, centrioles, and lysosomes.

Protein Production

The process in which DNA is transcribed into RNA, ribosomes translate RNA into proteins, and the Golgi modifies and packages the proteins.

Transcription

The process of copying DNA information into RNA.

Translation

The process in which ribosomes use RNA instructions to build proteins.

Protein Production Step 1

DNA in the nucleus is transcribed into RNA.

Protein Production Step 2

The nucleolus makes ribosomes.

Protein Production Step 3

Ribosomes move to the cytoplasm or rough ER.

Protein Production Step 4

Ribosomes translate RNA into proteins.

Protein Production Step 5

Proteins from the rough ER and cytoplasm are transported to the Golgi apparatus.

Protein Production Step 6

The Golgi apparatus modifies, packages, and ships proteins in vesicles.

Why are folded membranes advantageous?

Folded membranes provide more surface area for reactions to occur in a small space.

Cellular Respiration

The process that occurs in mitochondria and breaks down glucose to release energy.

Homeostasis

The maintenance of stable internal conditions in a cell.