Cell Structures

By: Amber Tharpe

Cell Theory1.All living things are

made of cells2.Cells are the smallest

unit of life3.Cells come from other

living cells

All Cells have 3 Things

1.DNA2.Cytoplasm3.Cell membrane

Two Main Types of Cells

Prokaryotic• No nucleus

– DNA floats in cytoplasm

• No membrane-bound organelles

• All single-celled• Bacteria and

Archaea

Eukaryotic• Has a “true nucleus”

– DNA is housed there• Has membrane-

bound organelles• Single or multicellular• Plants, animals, fungi,

and protists

Cytoplasm

•Jelly-like substance that cushions and protects the cell

Plasma membrane

•Double-layered membrane that surrounds cells

•Controls what goes in and out of the cell

Organelles•Structures that perform specific jobs in the cell

•Surrounded by membranes

Nucleus

• Round organelle in the center of cell

• Houses the DNA• Controls the activities of the cell

Nucleolus

•Found inside the nucleus•Makes ribosomes

Cytoskeleton

•Made of protein fibers•Provide structure and allow for movement

Endoplasmic Reticulum• Network of folded membranes with spaces

between• Extension of the nuclear envelope• Delivers lipids and proteins to the Golgi• Two types

– Smooth- without ribosomes• makes lipids

– Rough- studded with ribosomes• modifies proteins

Ribosomes

•Proteins are made here

•Found on rough ER and free floating in cytoplasm

Golgi Apparatus

• Aka Golgi body or Golgi complex• Close network of membranes and

vesicles pinch off of it• Processes, packages, and ships

proteins• Like UPS

Vesicle

•Small membrane-bound sacs that transport substances in the cell

Mitochondria

• Make energy for the cell in the form of ATP

• Known as the “powerhouse” of the cell

• Bean-shaped with folded inner membrane

Vacuole

• Fluid-filled sac used for storing materials

• Plant cells–Central vacuole for water storage

Lysosomes

•Contain enzymes used for digestion

•Break down and recycle old cell parts

Centrioles

•Involved in cell division

•Only found in animal cells

Cilia- in some cells

• Small hairlike projections• Allow for movement• Not found in all cells• Found in paramecium and

in respiratory tract

Flagella- in some cells

•Tail-like projections •Allow for movement•Found in sperm

Flagellum

Cell Wall

• Found in plants, fungi, and bacteria

• Found outside the cell membrane

• Provides protection and shape to the cell

Chloroplast

• Only found in plant cells• Contain chlorophyll• Involved in photosynthesis for

plants

Cell Membrane

By: Amber Tharpe

Cell Membrane

•Other names–Plasma membrane

Cell membrane

• 2 layers of phospholipids• Outer flexible boundary of cell• Controls what goes in and out

of the cell–Selectively permeable

•Allows some things to cross, while not allowing others

Phospholipids• 2 main parts

– Head• Phosphate• Polar (slightly charged)• Hydrophilic- loves water

– Tail• 2 fatty acid chains• Nonpolar (not charged)• Hydrophobic- hates water

Transport Proteins

–Act as channels to help materials cross