CellsCells

The basic units of life!!!The basic units of life!!!

The cellThe cell

How were cells discovered?How were cells discovered?

Robert HookeRobert Hooke– Discovered the first cell using a early compound Discovered the first cell using a early compound

microscope.microscope. CorkCork

Cell TheoryCell Theory

1. All living things are composed of cells1. All living things are composed of cells

2. Cells are the basic units of structure and 2. Cells are the basic units of structure and function in living thingsfunction in living things

3. New cells are produced from existing 3. New cells are produced from existing cells.cells.

2 Categories of Cells2 Categories of Cells

They are categorized by if they contain a They are categorized by if they contain a nucleus or not. nucleus or not.

The categories are:The categories are:

– 1. Eukaryotes1. Eukaryotes– 2. Prokaryotes2. Prokaryotes

EukaryotesEukaryotes

Contain a nucleusContain a nucleus LargeLarge Very complexVery complex Highly specializedHighly specialized Contain internal membranesContain internal membranes

Examples: Animals, plants, fungi, and Examples: Animals, plants, fungi, and protistsprotists

ProkaryotesProkaryotes

SmallSmall Not specializedNot specialized No true nucleus (they do still have genetic No true nucleus (they do still have genetic

information)information)

Example:Example:– BacteriaBacteria

What is the main job of the cell?What is the main job of the cell?

To make proteins. To make proteins. The cell has many complex processes that it The cell has many complex processes that it

goes through in order to make new proteins goes through in order to make new proteins for our body to use.for our body to use.

The next series of slides will walk you The next series of slides will walk you through each organelle and its job.through each organelle and its job.

Eukaryotic Cell StructureEukaryotic Cell Structure

The cell is divided into 2 main parts.The cell is divided into 2 main parts.– 1. The nucleus1. The nucleus– 2. The cytoplasm2. The cytoplasm

Both of these structures work together to get Both of these structures work together to get all jobs done inside the cell.all jobs done inside the cell.

The NucleusThe Nucleus“inventor”“inventor”

The control center of the cellThe control center of the cell Contains all of the cells DNAContains all of the cells DNA

– Includes coded instructions for making proteins.Includes coded instructions for making proteins.– The nucleus has the following structures inside The nucleus has the following structures inside

of it:of it: Nuclear envelopeNuclear envelope Chromatin (tiny pieces that later become Chromatin (tiny pieces that later become

chromosomes)chromosomes) nucleolusnucleolus

The CytoplasmThe Cytoplasm“the shop”“the shop”

• Located just outside the nucleusLocated just outside the nucleus• Hold all of the cells Hold all of the cells organelles.organelles.– OrganellesOrganelles are “tiny” cellular organs are “tiny” cellular organs

The cellular organelles we will be covering The cellular organelles we will be covering today are the following:today are the following:

– Ribosome'sRibosome's --Vacuoles--Vacuoles– Endoplasmic reticulumEndoplasmic reticulum --Mitochondria--Mitochondria– Golgi apparatusGolgi apparatus --Lysosomes--Lysosomes– CytoskeletonCytoskeleton

RibosomesRibosomes“finished instructions”“finished instructions”

This is where proteins are assembled.This is where proteins are assembled. They are They are found in the cytoplasm found in the cytoplasm and and

attached to the attached to the endoplasmic reticulumendoplasmic reticulum.. Their main job is to assemble proteins Their main job is to assemble proteins

following detailed instructions handed down following detailed instructions handed down to them from the nucleus.to them from the nucleus.

Endoplasmic ReticulumEndoplasmic Reticulum“assembly line”“assembly line”

This is where lipids are assembled to be sent This is where lipids are assembled to be sent out into the cell membrane.out into the cell membrane.

There are 2 typesThere are 2 types 1. Smooth ER1. Smooth ER

– No ribosomes, assembles lipids, makes enzymesNo ribosomes, assembles lipids, makes enzymes

2. Rough ER2. Rough ER– Has ribosomes on it, also stores proteins until Has ribosomes on it, also stores proteins until

they are sent to the Golgi Apparatus.they are sent to the Golgi Apparatus.

Golgi ApparatusGolgi Apparatus“customization”“customization”

Modifies, sorts, and packages the proteins Modifies, sorts, and packages the proteins from the ER.from the ER.

Prepares and stores proteins in the cell or Prepares and stores proteins in the cell or excretes them from the cell into other parts excretes them from the cell into other parts of the body.of the body.

The finishing touches are put on the proteins The finishing touches are put on the proteins here before they leave the cell.here before they leave the cell.

LysosomesLysosomes“cleanup crew”“cleanup crew”

There job is to There job is to break down waste break down waste and and recycle it to be used by the cell.recycle it to be used by the cell.

They are filled with enzymes that help them They are filled with enzymes that help them break down and digest lipids, break down and digest lipids, carbohydrates, and proteins.carbohydrates, and proteins.

MitochondriaMitochondria“Power Source”“Power Source”

Convert food into chemical energy the cell Convert food into chemical energy the cell can use.can use.

CytoskeletonCytoskeleton“Shop Walls”“Shop Walls”

Helps the cell maintain it’s shapeHelps the cell maintain it’s shape Also involved in movementAlso involved in movement

VacuoleVacuole

They are saclike in structureThey are saclike in structure

Function: they store materials like water, Function: they store materials like water, salts, proteins, and carbohydrates.salts, proteins, and carbohydrates.

FlagellumFlagellum

It is a long tail or whip like structure.It is a long tail or whip like structure.

Its function is to provide a cell with movement.Its function is to provide a cell with movement.

Example: Sperm cell Example: Sperm cell

CiliaCilia

These are very tiny hairs located on the These are very tiny hairs located on the outside of some very small eukaryotes.outside of some very small eukaryotes.

Function: To provide movement.Function: To provide movement.

Also found inside the nose and inside the Also found inside the nose and inside the lining of the respiratory and digestive tract.lining of the respiratory and digestive tract.

ChloroplastChloroplast

Only found in plant cellsOnly found in plant cells

Function: They capture energy from the sun Function: They capture energy from the sun and convert it into chemical energy that the and convert it into chemical energy that the plant can use.plant can use.– This process is called This process is called photosynthesisphotosynthesis

Structure: They look like green skittles.Structure: They look like green skittles.

CentriolesCentrioles

They are made up of tiny fibers called They are made up of tiny fibers called tubulin.tubulin.

Located near the nucleusLocated near the nucleus

Help the cell divide. Help the cell divide.

Cell WallCell Wall

They are found in plants, algae, and fungi.They are found in plants, algae, and fungi.

Structure: They are thick and rough. They Structure: They are thick and rough. They have many pores in them that allow water, have many pores in them that allow water, oxygen and carbon dioxide through.oxygen and carbon dioxide through.

Function: Provide support and protection for Function: Provide support and protection for the cell.the cell.

Cell MembraneCell Membrane

Also known as the phospholipid bi-layer.Also known as the phospholipid bi-layer.– Structure: Made of 2 layers of lipids. There are Structure: Made of 2 layers of lipids. There are

also proteins stuck inside of the lipid layers that also proteins stuck inside of the lipid layers that act as doorways to allow large molecules to act as doorways to allow large molecules to pass.pass.

Function: Controls what enters and leaves Function: Controls what enters and leaves the cell. Also provides protection. the cell. Also provides protection.