Cell Organelles

The Work of Cells

Cells must perform many important jobs for an organism to live:

gas exchange: O2 in & CO2 out

digest food - - - breakdown macromolecules, starch into glucose

make energy --- breakdown glucose into ATP

build molecules - - - build macromolecules

remove wastes - - - CO2, water, lactic acid

Organelles do the work of cells Each organelle has a specific job

Organelles - are membrane-bound structures within the cell that have specific functions.

Eukaryotic cells contain specialized structures that perform specific functions.

The cell is like a factory. Cells, like factories, follow instructions and produce products.

General Motors Plant

The different organelles can be compared to the inassembly lines of the factory.

specialized machines

Which macromolecule is the workhorse of the cell?

PROTEINS

SEVERAL ORGANELLES ARE INVOLVED IN MAKING AND PROCESSING PROTEINS:NucleusNucleolusRibosomesEndoplasmic reticulumGolgi apparatusVesicles

Nucleus

Nucleus

large, round organelle located in the center of the cell.

DNA

DNA contains the genetic information, the instructions for making proteins.

The nucleus is the storehouse for DNA.

Function of the Nucleus:

(1) a storehouse ---DNA is stored and is available for use when needed. (2) a safe --- DNA is isolated and protected from possible damage.

The nucleus is like the in a factory.

main office

Prokaryotic Cells

but they do have DNA

have no nucleus and no organelles

Nucleolus

Nucleolus

organelle located inside the nucleus.makes ribosomes.

Ribosomes ---

Ribosomes

protein

protein machines!

small structures that make proteinsfor the cell.

Ribosomes make

Ribosomes

protein

proteins!

Ribosomes can be found: free in the cytoplasm

Where they make proteins for use inside the cell.

Ribosomes can be found: attached to the ER --- Rough ER

makes proteins that will be exported out of the cell.

Endoplasmic reticulum-- ER an extensive interconnected network

of highly folded membranes.

Endoplasmic Reticulum

Endoplasmic reticulum-- ER

There are two types of ER: Rough ER – has attached ribosomes

and Smooth ER – has no ribosomes

Rough ER Function: To make proteins for export out of cell

What is the function of the small intestine? Digestion

What is the function of the pancreas?

What is the function of the pancreas?

To make digestive enzymes (proteins) to be transported out of the pancreas for use in the small intestine.

Pancreatic cells have a large amount of rough ER because they must make digestive enzymes (proteins) and export them to the small intestine.

Rough ER makes proteins for export out of cell

Proteins made by the attached ribosomes enter the ER, are modified, are put into vesicles, and are transported to the Golgi apparatus.

Smooth ER

--- Function: To makes lipids &to break down toxic substances.

There are many lipids

Smooth ER

Vesicle w/Lipid

Smooth ER makes lipids and the Golgi apparatus exports them out of cell to their proper destinations.

…fats, oils, and cholesterol.

Smooth ER also breaks down toxic substances such as alcohol, drugs, and poisons so they can be eliminated by the body.

Liver cells have large amounts of smooth ER.

Liver cells make cholesterol.

Liver cells also break down toxins so they can be expelled from the body.

cholesteroltoxins

A lipid

Golgi apparatus a set of flattened, membrane-bound sacs.

Golgi apparatus

Looks like a stack of pita bread

Golgi apparatus --- Post Office of the cell

Golgi apparatus

It is the packaging

and distribution center of the cell.

Proteins and lipids generally move from the ER to the Golgi apparatus.

In the Golgi, proteins and lipids are modified, packaged, and delivered to their appropriate destinations.

Golgi apparatus

FUNCTION:

The golgi apparatus ________________, ________________, and______________________________________

modifies proteinspackages proteinsdelivers proteins to their proper destinations.

Vesiclessmall, membrane-bound sacs that store and transport substances in the cell.

Substances such as proteins and lipids are stored and transported within vesicles.

Vesicles

SUMMARY:

(2)Part of the ER pinches off to form a vesicle enclosing the protein.

(3)The protein-vesicle travels to and merges with the Golgi.

(4)The protein is modified and packaged in a new vesicle for transport.

(1)A protein is made in rough ER. (1)

(2) (3)

(4)

OTHER ORGANELLES HAVE VARIOUS FUNCTIONS:

MitochondriaChloroplastsLysosomesVacuoles

Mitochondriaorganelles that make energy for the cell in the form of ATP.

Mitochondria

MitochondriaPowerhouse

of theCell

The mighty mitochondria

makes power---makes energy.

Mitochondria convert organic compounds you eat into ATP, the main energy source of cells.

ATP

Mitochondria Cellular Respiration: C6H12O6 + O2 CO2 + H2O + ATP

ATP

Where glucose is broken down to make energy, ATP.

Some cells have a few mitochondria… some have hundreds or even thousands.

Brain cells and muscle cells have a large amount of mitochondria because they require a lot of energy.

Chloroplast oval-shaped, green organelles

Chloroplast

found only in the cells of plants and algae.

Chloroplast contain chlorophyll, a green pigment that absorbs light energy.

Makes leaves GREEN!

Chloroplasts carry out photosynthesis --- make food for the cell.

Photosynthesis:

CO2 + H2O + light energy C6H12O6 + O2

carbon dioxide glucose oxygenwater sunlight+ + +

Lysosomessmall membrane-bound sacs that contain enzymes used to digest macromolecules.

Lysosomes

REMEMBER…Lysosomes contain Enzymes!

Old or damaged organelle

lysosome

break down and recycle old cell parts (organelles) by breaking down macromolecules.

Function:

Lysosomes also defend a cell from invading bacteria and viruses by engulfing and destroying the pathogens.

Amoeba engulfing food particles

Central vacuolevery large sac found in plant cells that stores water.

Central vacuole

When full, the water vacuole makes the cell rigid and helps support the plant. When a plant wilts, its leaves shrivel because there is not enough water in the central vacuole to support the leaf.

Structures found only in plant cells

(1) Cell wall

(2) chloroplast

(3) Central vacuole

Cell wall

Centralvacuole

Chloroplast