Cell Organelles and Functions

Outside the Cell - Cell Wall Made of cellulose Freely permeable to water and most solutes Only in Plant cells Maintains cell turgidity Provide mechanical support Protect from mechanical damage

Extensions of the cell – Cilia / Flagella Used for movement Cilia are tiny hair- like projections Flagella are long tail-like projection Arrangement of microtubules

Holding it all together - Cell Membrane Phospholipid bilayer containing proteins, cholesterol and carbohydrates Separates cell contents from the environment; regulates movement of substances into and out of the cell

The Fluid within - Cytoplasm Fluid that encompasses the inside of the cell’s membrane and outside the nucleus Site of many chemical reactions Give cell its structure Where the organelles are located

Organelles in the Cytoplasm (eukaryote) - Nucleus Membrane Bound spherical structure Control centre of the cell contains the genetic material

In the Nucleus-(eukaryote) Chromatin/Chromosomes Threadlike Deoxyribonucleic Acid (DNA) and associated proteins Genetic Material Also goes by the name chromosomes, sister chromatids at various stages of cell life

In the Nucleus (cont’d) Nucleolus Dense, spherical structure; composed of DNA, RNA and protein Site of ribosome synthesis

Around the Nucleus – Nuclear Membrane Phospholipid - protein bilayer; contains pores Controls what enters and leaves the nucleus

Organelles in the Cytoplasm - Endoplasmic Reticulum (ER) Membrane bound channels running throughout the cell Network of channels

*Rough ER Ribosomes attached to outside Involved in protein synthesis and transportation of molecules

*Smooth ER Ribosomes NOT attached to outside Synthesis of lipids and transportation of molecules in the cell

Organelles in the Cytoplasm - Golgi Apparatus/bodies Flattened, membrane bound, fluid filled disks, with associated vesicles surrounding the disks Involved in the packaging of proteins, lipids and carbohydrates

Organelles in the Cytoplasm - Ribosomes Small spherical bodies free floating in the cytoplasm or attached to ER Composed of ribosomal RNA and protein Site of protein synthesis

Organelles in the Cytoplasm - Lysosome Membrane bound spherical sacs, containing enzymes pH of approx. 5 Site of digestion and storage of digestive enzymes Can destroy harmful invaders to the cells

Organelles in the Cytoplasm - Vacuole Membrane bound, fluid-filled sacs Storage of food or water In plants, involved in turgor pressure

Organelles in the Cytoplasm - Centriole Paired cylindrical structures, composed of protein Found only in Animal Cells Assist in cell reproduction by producing spindle fibres (a type of microfilament) Assists in the formation of cilia and flagella

Organelles in the Cytoplasm – Chloroplasts (next unit) Used for absorption of light Only in plants Site of photosynthesis A series of chemical reactions resulting in the production of glucose and ATP from sunlight and other raw materials

Mitochondria (next unit) Membrane bound, bean shaped mostly protein, but also contain lipids, DNA and RNA Mitochondrial DNA is passed down from the mother only Site of Aerobic Metabolism Releases energy from food in the form of ATP