Q’s pg.79 #1-6

3.2 Cell Organelles

Cell organelles Q: What is the difference between a plant and an animal cell? Plant cell – chloroplasts, central vacuole and cell wall Animal cell – centrioles and lysosomes

Cell Organelles - Structures perform processes in a cell.

Cytoskeleton Network of proteins that crisscross the cell. 3 main types of fibers: Microtubles – long hollow tubes. Give cell its shape and act as “tracks” for movement of organelles. Intermediate filaments – smaller than microtubules. Give cell its strength. Microfilaments – Smallest. Tiny threads that enable cells to move and divide.

Nucleus Stores most of the genetic information, or DNA, in your cells. DNA contains genes that are the instructions for making proteins. protects DNA and allows access to DNA at certain times. Nuclear envelope – a double membrane around the nucleus. Has pores that let molecules pass between the nucleus and cytoplasm. Nucleolus – dense area inside the nucleus, contains ribosomes.

Endoplasmic Reticulum (ER) A lot of thin folded membranes Lumen – the inside space of the ER Rough ER – area that is covered with ribosomes. Ribosomes make proteins and then move into the cytoplasm. Smooth ER – area that doesn’t have ribosomes. Makes lipids.

Golgi Apparatus Layers of membrane-enclosed spaces that process, sort, package, store and deliver proteins. Has enzymes that change proteins

Vesicles Small membrane-bound sacs that transport material. Protects and transports proteins from the ER to the Golgi Apparatus.

Mitochondria Supply energy to the cell Are bean shaped, and have 2 membranes Inner membrane has many folds and converts molecules from food you eat into energy Have their own ribosomes and DNA. This may mean that they were originally prokaryotes that larger cells took in.

Vacuole Fluid-filled sac that stores material, such as water, food, enzymes. Most animal cells have many small vacuoles. Plant cells have a large vacuole in the center that is filled with watery fluid and sometimes toxins. It strengthens and supports the plant.

Lysosomes Membrane-bound organelles that contain enzymes They defend a cell from invading bacteria and viruses by engulfing and digesting targeted molecules. They also break down damaged or worn-out cell parts. There are many in animal cells, but we are not sure if plant cells have them.

Centrosome Small region of cytoplasm that produces microtubules. Contains 2 Centrioles, which are cylinder-shaped organelles made of short microtubules. Centrioles are involved in animal cell division. Centrioles organize microtubules to form cilia and flagella.

Cell Wall Layer that gives protection, support and shape to the cell. Composition changes with different types of organisms. Eg. Plants – wall made out of cellulose. Fungi – wall made out of Chitin.

Chloroplasts Do photosynthesis (convert solar energy into energy the cell can use) Have an outer and an inner membrane. Thylakoids – disc-shaped sacs in the inner membrane that contain chlorophyll. Chlorophyll – green and absorbs light. Has its own ribosomes and DNA (like mitochondria, so maybe they were free living prokaryotes as well) Chloroplasts work with mitochondria to capture and convert energy. Found in plant cells and some other organisms, such as green algae

Which organelles are involved in making and processing proteins? Choose either the plant cell or the animal cell and draw and label the different parts. Refer to pg. 75 Tomorrow we will have a quiz: Some review q’s you can do are: pg. 95 #1-19