Cell Structure. Two Cell Types 1. Prokaryotic Cells- Simple cells made up of a cell wall, cell membrane, cytoplasm, and DNA. They do not have membrane

Cell StructureCell Structure

Two Cell TypesTwo Cell Types

1.1. Prokaryotic Cells-Prokaryotic Cells- Simple cells made up Simple cells made up of a cell wall, cell membrane , cytoplasm, of a cell wall, cell membrane , cytoplasm, and DNA. They do not have membrane and DNA. They do not have membrane bound organelles. Ex. Bacteriabound organelles. Ex. Bacteria

2.2. Eukaryotic Cells-Eukaryotic Cells- are cells with are cells with specialized organelles that are held specialized organelles that are held together by a membrane. They have a together by a membrane. They have a central organelle called a nucleus that central organelle called a nucleus that controls all the cell’s activities and controls all the cell’s activities and contains the DNA.contains the DNA.

Plasma MembranePlasma Membrane Is the flexible boundary of a cell that separates a Is the flexible boundary of a cell that separates a

cell from its surroundings.cell from its surroundings. It allows nutrients to enter the cell and waste to It allows nutrients to enter the cell and waste to

be removed.be removed.– This healthy balance is called This healthy balance is called Homeostasis.Homeostasis.

To maintain this homeostasis the plasma To maintain this homeostasis the plasma membrane allows some molecules into the cell membrane allows some molecules into the cell and keeps others out. This is called and keeps others out. This is called Selective Selective PermeabilityPermeability. Pg 176. Pg 176

Some molecules are allowed in at any time and Some molecules are allowed in at any time and others are only admitted at certain times and in others are only admitted at certain times and in limited quantities. Others are not allowed in at limited quantities. Others are not allowed in at all.all.

Structure of the Plasma Structure of the Plasma MembraneMembrane

The plasma membrane is made up of two layers of The plasma membrane is made up of two layers of phospholipids that are arranged back to back. This phospholipids that are arranged back to back. This is called the is called the phospholipid bilayerphospholipid bilayer. Pg 177. Pg 177

The phosphate group or the head is polar (which The phosphate group or the head is polar (which water is also polar so they interact well together) water is also polar so they interact well together) which allows the plasma membrane to interact which allows the plasma membrane to interact with its watery environment.with its watery environment.

The fatty acid tail is nonpolar which avoids water The fatty acid tail is nonpolar which avoids water and is water insoluble.and is water insoluble.

So the outside of the plasma membrane is water So the outside of the plasma membrane is water soluble and the inside of the membrane is water soluble and the inside of the membrane is water insoluble. This means that water soluble molecules insoluble. This means that water soluble molecules will not easily move through the membrane b/c will not easily move through the membrane b/c they are stopped by this water insoluble layer.they are stopped by this water insoluble layer.

Transport ProteinsTransport Proteins

They regulate which molecules are They regulate which molecules are allowed to enter and which are allowed to enter and which are allowed to leave the cell. Called allowed to leave the cell. Called Selective Permeability.Selective Permeability.

Eukaryotic Cell StructureEukaryotic Cell Structure

Cellular Boundaries pg 180Cellular Boundaries pg 180– Cell wallCell wall is a rigid wall outside the is a rigid wall outside the

plasma membrane that dives extra plasma membrane that dives extra support and protection to the cell.support and protection to the cell.

– Plasma MembranePlasma Membrane is inside the cell wall is inside the cell wall and acts as a flexible boundary of the and acts as a flexible boundary of the cell.cell.


The Nucleus and Cell Control pg 181The Nucleus and Cell Control pg 181– The The nucleusnucleus directs the activity of a cell’s directs the activity of a cell’s

organelles and contains directions to make organelles and contains directions to make proteins.proteins. The nucleus is surrounded by the The nucleus is surrounded by the nuclear envelopenuclear envelope

which is the boundary in between the nucleus and which is the boundary in between the nucleus and the cytoplasm.the cytoplasm.

– It also contains the DNA that is in strands It also contains the DNA that is in strands called called ChromatinChromatin. The chromatin tells the cell . The chromatin tells the cell what kinds of proteins to make. When the cell what kinds of proteins to make. When the cell divides the chromatin condenses and becomes divides the chromatin condenses and becomes chromosomes.chromosomes.


The The NucleolusNucleolus, which is inside the , which is inside the nucleus, makes ribosomes.nucleus, makes ribosomes.– RibosomesRibosomes are where the cell are where the cell

makes protein, which is made up of makes protein, which is made up of RNA.RNA. Ribosomes make the proteins in the Ribosomes make the proteins in the

cytoplasmcytoplasm..

– The The CytoplasmCytoplasm is a thick fluid in the cell. is a thick fluid in the cell.


Assembly, Transport, and Storage pg 182Assembly, Transport, and Storage pg 182– Endoplasmic ReticulumEndoplasmic Reticulum (ER) is a series of (ER) is a series of

tightly folded membranes floating in the tightly folded membranes floating in the cytoplasm. It is the site of cellular chemical cytoplasm. It is the site of cellular chemical reactions.reactions. Two typesTwo types

– Rough ERRough ER is where ribosomes attach and make is where ribosomes attach and make proteins. Other ribosomes float freely in the cytoplasm. proteins. Other ribosomes float freely in the cytoplasm. Each protein has a specific job. Ex. Part of the plasma Each protein has a specific job. Ex. Part of the plasma membrane.membrane.

– Smooth ERSmooth ER does not have ribosomes attached and also does not have ribosomes attached and also performs chemical activities such as making and performs chemical activities such as making and storing lipids.storing lipids.


Other Organelles pg 183Other Organelles pg 183– Golgi Apparatus)Golgi Apparatus) (or golgi body) sorts proteins and (or golgi body) sorts proteins and

then packs them into structures called vesicles. then packs them into structures called vesicles. The vesicles are then sent to where they are The vesicles are then sent to where they are needed.needed. When the golgi body packages digestive enzymes they When the golgi body packages digestive enzymes they

form a lysosome. A form a lysosome. A lysosomelysosome breaks down old cell parts breaks down old cell parts and removes waste. and removes waste.

– VacuoleVacuole is a sac inside a membrane where is a sac inside a membrane where materials needed by the cell are temporarily materials needed by the cell are temporarily stored. Some store food and enzymes and others stored. Some store food and enzymes and others store waste until they can be removed or excreted.store waste until they can be removed or excreted.


Energy Transformers pg 184 & 185Energy Transformers pg 184 & 185– MitochondriaMitochondria is the cell’s powerhouse. It is the cell’s powerhouse. It

transforms energy for the cells of plants and transforms energy for the cells of plants and animals.animals.

– Mitochondria stores the energy in bonds that the Mitochondria stores the energy in bonds that the cells can access easily when energy is needed.cells can access easily when energy is needed. In green plants and some protists energy is received In green plants and some protists energy is received

from light energy by the chloroplasts.from light energy by the chloroplasts. Chloroplasts are a type of plastid that re plant Chloroplasts are a type of plastid that re plant

organelles that store things.organelles that store things. Chloroplasts contain chlorophyll (a green pigment) Chloroplasts contain chlorophyll (a green pigment)

which makes leaves and stems green.which makes leaves and stems green.


Support and LocomotionSupport and Locomotion– CytoskeletonCytoskeleton is inside the cell and supports the is inside the cell and supports the

organelles in the cytoplasm. It can be take organelles in the cytoplasm. It can be take apart in on place and put back together in apart in on place and put back together in another, when this happens the cell changes another, when this happens the cell changes shape.shape. It is made up of microtubules and microfilaments.It is made up of microtubules and microfilaments.

– MicrotubulesMicrotubules are tiny cylinders of protein. are tiny cylinders of protein.– MicrofilamentsMicrofilaments are even smaller solid protein fibers. are even smaller solid protein fibers.– They support the organelles and help materials move They support the organelles and help materials move

around the cell.around the cell. CentriolesCentrioles are made of microtubules and are very are made of microtubules and are very

important in cell division.important in cell division.


Two other organelles made from Two other organelles made from Microtubules areMicrotubules are– CiliaCilia which are short projections that look which are short projections that look

like hairs. They move in a wave like like hairs. They move in a wave like motion and cells have many of them.motion and cells have many of them.

– FlagellaFlagella are longer projections that move are longer projections that move in a whip like motion. A cell usually has in a whip like motion. A cell usually has one or two flagella. one or two flagella.

– In a one celled organism the cilia and In a one celled organism the cilia and flagella are the most important way of flagella are the most important way of moving.moving.

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Cell Structure. Two Cell Types 1. Prokaryotic Cells- Simple cells made up of a cell wall, cell membrane, cytoplasm, and DNA. They do not have membrane