Cell Structure & Function

Cell Theory All living things are made up of cells. Cells are the basic unit of structure and function in living things. All cells are produced from other cells.

Definition of Cell A cell is the smallest unit that is capable of performing life functions.

Two Types of Cells Prokaryotic Eukaryotic

Prokaryotic “ An organism whose cells lack a nucleus and some other cell structures.” Do not have structures surrounded by membranes Few internal structures One-celled organisms, Bacteria

Eukaryotic “ An organism whose cells contain nuclei. ” Contain organelles surrounded by membranes Most living organisms PlantAnimal

“Typical” Animal Cell

“Typical” Plant Cell

Cell Parts Organelles

Cell Membrane Outside cell boundaries that controls which substances can enter or leave the cell. Double layer

Cell Wall A rigid layer of nonliving material that surrounds the cells of plants and some other organisms. Supports & protects cells Surrounds cell membrane

Inside the Cell

Nucleus The control center of a eukaryotic cell that directs the cell’s activities and contains the information that determines the cell’s form and function. Separated from cytoplasm by nuclear membrane Contains genetic material - DNA

Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus

Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics A doubled rod of condensed chromatin

Nucleolus Inside nucleus Contains RNA to build proteins

Cytoplasm Gel-like mixture Surrounded by cell membrane Contains hereditary material

Endoplasmic Reticulum A cell structure that forms passageways in which proteins and other materials are carried through the cell. Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface

Ribosomes Grain-like Makes proteins Some attach to endoplasmic reticulum; others float in the cytoplasm

Mitochondria Rod-shaped cell structures that convert energy in food molecules to energy the cell can use to carry out its functions. Produces energy through chemical reactions – breaking down fats & carbohydrates Controls level of water and other materials in cell Recycles and decomposes proteins, fats, and carbohydrates

Golgi Bodies Protein 'packaging plant‘ Move materials within the cell Move materials out of the cell

Lysosome Small, round structures containing chemicals that break down certain materials. Digestive 'plant' for proteins, fats, and carbohydrates Transports undigested material to cell membrane for removal

Vacuoles Membrane-bound sacs for storage, digestion, and waste removal Contains water solution Help plants maintain shape

Chloroplast Usually found in plant cells Contains green chlorophyll Where photosynthesis takes place

Compare and Contrast Plant and Animal Cells Animal Cells Plant Cells *Cell membrane*Cell Wall *Cytoplasm*Cell Membrane *Vacuoles*Cytoplasm *Nucleus*Vacuoles *Chloroplasts *Nucleus