“Every Part has its Own Job to do….” Organelle Functions “Every Part has its Own Job to do….”

Organelles Organelles are the small parts of a cell. Each organelle has a specific function or job. The shape (structure) of the organelle allows it to have this function. You should learn to: 1. Recognize and label organelles in a diagram. 2. Describe the functions of each organelle.

The Way it’s Put Together Structure vs. Function Structure How it’s Built What it’s Made Of Parts Shapes The Way it’s Put Together Sizes Function What it Does How it Works It’s Jobs The Way it works Steps in the Process “The Structure Determines the Function” This is almost a “Law” of Biology – it is true at all Levels of Organization Errors in structure cause errors in function, which will cause diseases, disorders, etc.

Your Assignment Finish these notes and turn them in by the end of the period. You should draw an arrow on each diagram showing the organelle of interest. The “main function” of each organelle is underlined to help you know what is most important about it.

Cytoplasm Found between the nucleus and the cell membrane It is More than just the “fluid filling the cell” It allows chemical reactions to occur, since the dissolved molecules can interact with each other easily. Most organelles are floating in the cytoplasm

Cell Wall You do NOT have any cell walls! WARNING: Neither do ANY other animals! But you eat them whenever you eat fruits or vegetables!! And you use them every time you work with something wooden! And you are writing on them right now! And you might be wearing them if your clothes are cotton! Found only in plants, fungi, and bacteria Thick outer layer that provides support and protection for cell

Cell Membrane Found in all cells (plants and animals, prokaryotes and eukaryotes) Many important functions: Controls entry and exit of molecules in and out of cell (it is a “semipermeable membrane”) Recognizes surrounding cells and other parts of the environment Joins cells together into tissues Sends & receives messages from other cells

Nucleus Found in all eukaryotic cells Controls all cell activities using instructions from DNA Contains nucleolus and chromatin (DNA) Pores in nuclear membrane allow RNA to exit nucleus chromatin

Nucleolus Builds ribosomes Ribosomes exit nucleus to function in cytoplasm

Chromatin Loose, unwound strands of DNA Unwound DNA allows access to genes DNA winds up tightly into chromosomes during mitosis Chromosomes carry the genetic code with instructions for all of a cell’s traits & actions DNA Molecules Genes Chromosomes

Mitochondrion “The powerhouse of the cell” Provides energy by “burning” sugar with oxygen Conducts aerobic cellular respiration Equation for Cellular Respiration Glucose Sugar Carbon Dioxide Oxygen + Water + Energy!! +

Ribosomes Build Proteins following instructions from DNA “Free Ribosomes” floating in cytoplasm “Attached Ribosomes” on Rough E.R. Magnified View of Ribosome (Dots) Large Subunit Small Subunit

Cilia Rows of many tiny “hairs” that act like oars Move the cell or move materials past the cell Singular: cilium plural: cilia A cell with cilia is “ciliated” A protist that moves with cilia is a “ciliate”

Centrioles Found only in animal cells Builds the cytoskeleton Also has an important role in cell division: it pulls the pairs of chromosomes apart

Vacuoles Storage compartments May hold food molecules, water, or waste molecules Water-filled vacuole is very large in plant cells – it influences the shape of the plant, since the plant wilts when it is empty

Golgi Apparatus Secretes important molecules which act outside of the cell Not involved in excretion (release of waste molecules) Golgi packs helpful molecules into vesicles, and the vesicles join with the cell membrane to release the molecules Vesicle ready to release important molecules like hormones, enzymes, or neurotransmitters.

Flagellum Long whip-like tail Some cells have more than one Move the cell or move materials past the cell Singular: flagellum plural: flagella A cell with a flagellum is “flagellated” A protist that moves with a flagellum is a “flagellate”

Endoplasmic Reticulum Transports molecules throughout the interior of the cell Rough E.R. has ribosomes attached to it; its main job is to manufacture and transport proteins Smooth E.R. does not have ribosomes; it mostly transports fats and carbohydrates

Chloroplast Found only in plant cells (and some protists) Traps the sun’s energy and builds food molecules Conducts photosynthesis Chlorophyll is a green molecule inside the chloroplast (membrane) (sacs) Equation for Photosynthesis (space) Carbon Dioxide Glucose Sugar + Water + Light + Oxygen

Cytoskeleton Made of microfilaments and microtubules Supports the cell and helps keep its shape Electron Micrograph of Cytoskeleton Green Fibers = Cytoskeleton Purple Circle = Nucleus

Lysosomes Contain powerful digestive enzymes Break down foreign substances and worn-out cell parts May cause misfunctioning cells to self-destruct Only in animal cells