A BREIF OVERVIEW OF ORGANELLES

Look for information on each organelle’s location and job. Pay attention to incomplete information, you will need to do some research to fill in the missing material.

Visit www.worldofteaching.com For 100’s of free powerpoints

What could the job of the cytoplasm be? jelly-like material with organelles in it. cytosol Soluble part of the cytoplasm that is left when all organelles are removed consists mainly of water with dissolved substances such as amino acids in it. What could the job of the cytoplasm be?

Nucleus Nucleus nucleolus nuclear pores the media center of the cell the largest organelle in the cell it contains the DNA of the cell. DNA (Deoxyribonucleic Acid) contains all the information for cells to live, perform their functions and reproduce.  nucleolus Organelle inside the nucleus responsible for making ribosomes. nuclear pores circles on the surface of the nucleus where ribosomes, and other materials move in and out of the cell. Could a cell survive without a nucleus?

Mitochondria Mitochondria are membrane-enclosed organelles found in the cytosol main job is the conversion of the potential energy of food molecules into ATP. Every type of cell has a different amount of mitochondria. There are more mitochondria in cells that have to perform lots of work, for example- your leg muscle cells, heart muscle cells etc. Cells that need less energy to do their work have less mitochondria. Why does the food you eat need to be broken down before a cell can use it?

Mitochondria Structure: outer membrane that encloses the entire structure inner membrane that encloses a fluid-filled matrix the inner membrane is elaborately folded with shelf-like cristae projecting into the matrix. between the outer and inner membrane is the intermembrane space Why is the mitochondria shaped this way?

Endoplasmic reticulum (ER) A network of membranes throughout the cytoplasm of the cell. Sometimes called the Intercellular Highway. There are two types of ER: rough ER ribosomes are attached to it where most protein synthesis occurs in the cell smooth ER no ribosomes attached synthesizes lipids helps in the detoxification of harmful substances in the cell. Why is the Endoplasmic Reticulum located near the nucleus of a cell?

Golgi Body (AKA golgi complex or Golgi apparatus) responsible for sorting and correctly shipping the proteins produced in the ER.  Just like our postal packages which should have a correct shipping address, the proteins produced in the ER, should be correctly sent to their respective address.  If the Golgi complex makes a mistake in shipping the proteins to the right address, certain functions in the cell may stop.  What might happen if the golgi ships a protein to the wrong place in a cell?

Ribosomes help in the synthesis of proteins. 2 types Free (found in cytoplasm) make proteins for the cell Attached (attached to the ER) make proteins for the cell or proteins to be exported from the cell for work elsewhere in the body Ribosomes are made up of two parts, called subunits.  They get their names from their size. One unit is larger than than the other so they are called large and small subunits.  Both these subunits are necessary for protein synthesis in the cell. When the two units are docked together with a special information unit called messenger RNA, they make proteins.  Every living cell has a membrane, DNA and ribosomes. Why do you think all cells have ribosomes?

Vesicles term literally means "small vessel". organelle helps store and transport products produced by the cell. The vesicles are the transport and delivery vehicles like our mail and  Federal Express trucks. Some vesicles deliver materials to parts of the cell and others transport materials outside the cell in a process called exocytosis.                        Why does a cell use a vesicle to store and transport things rather than just send the item out unprotected in the cell?

Lysosomes function as the cell's recycling compartment or as a cell’s custodial staff. Are found only in animal cells Lysosomes take in cell waste (like used up proteins and lipids) that needs digesting. The metabolites (particles) that result are shipped out of the cell either by vesicles or directly across the membrane. If a cell had no lysosome, how would its internal environment change?

                      Steps in lysomal formation The ER and Golgi apparatus make a lysosome The lysosome fuses with a digestive vacuol Activated acid hydrolases digest the contents

centrioles appear only during mitosis or meiosis Review your mitosis notes to see what they do

Other cell parts cilia Flagella Cells may have many flagella or one thread-like projections beat in a regular fashion to create currents that sweep materials along Flagella Cells may have many flagella or one Help cells to move

PLANT CELL SPECIFIC PARTS View the slides then do the following: List 3 items that are found only in plant cells. Explain how the presence of these unique cell parts have helped plants to succeed on Earth. Describe how would you determine if a cell you are looking at under a microscope is a plant cell or an animal cell.

Chloroplast found only in plant cell cytoplasm Contain chlorophyll Give plants their green color Reflect green light but absorb all other colors Location of photosynthesis Process where light energy of the sun is converted into chemical energy. The chemical energy produced is used to make carbohydrates like starch, that get stored in the plant.                         Why are chloroplasts green?

Vacuoles and vesicles storage organelles in cells. Both store water, waste products, food, and other cellular materials Vacuoles are larger than vesicles. A large central vacuole can take up most of the plant cell's volume. Tonoplast is the membrane surrounding the plant cell vacuole         What happens to a cell when all of the materials it has stored in a central vacuole are used up?

cell wall distinguishing feature of a plant cell protects the cellular contents gives rigidity to the plant structure Made of cellulose, polysaccharides and glycoproteins provides a porous medium Plasmodesmata openings in cell wall used to communicate Used to transport materials between plant cells regulates growth and protects  the plant from disease.         .

Identify the 4 cell parts found in every type of cell (prokaryote and eukarote). List 3 items that are found only in plant cells. You are looking at a cell under a microscope. Describe what features you would use to determine if the cell you are looking at is a plant cell or an animal cell. Explain how an organelles structure is related to its function.