UNIT 1 - Ch5-CELL STRUCTURE & FUNCTION P

TYPES OF CELLS w Cells come in a variety of shapes and sizes that suit their diverse functions.

OBJECTIVES 1. Explain the relationship between cell shape and function. 2. Identify the factor that limits cell size. 3. Describe the three basic parts of a cell. 4. Compare prokaryotic cells and eukaryotic cells. 5. Compare plant and animal cells 6. Know the organelles and their functions

CELL DIVERSITY w Not all cells are alike. Even cells within the same organism show Enormous Diversity in Size, Shape, and Internal Organization. Your Body contains at least 200 Different Cell Types.

CELL SHAPE w Most Cells have a Specific Shape. w THE SHAPE OF A CELL DEPENDS ON IT'S FUNCTION. w Cells of the Nervous System that carry information from your toes to your brain are long and threadlike. w Blood Cells are shaped like round disk that can squeeze through tiny blood vessels.

CELL SIZE w A few types of cells are large enough to be seen by the unaided eye. Eg. The Female Egg w Most cells are visible only with a microscope.

MOST CELLS ARE SMALL FOR TWO REASONS: #1-Cells are limited in size by the RATIO of their Surface Area to Volume. The ration of Surface Area / Volume decreases as the cell size increases. (less SA compared to the Vol) This is important because the nutrients, oxygen, and other materials a cell requires must enter through it surface & waste must exit #2 – Processes such as Diffusion are slow and inefficient over large distances which limits nulceus ability to controle lg cells and effeciency of nutrient exchange within the cell

COMPARING CELLS w All cells share common features, such as a plasma membrane, cytoplasm, ribosomes, and genetic material (DNA). w But there is a high level of diversity among cells, there are significant differences between prokaryotes and eukaryotes. In addition plant cells have features that are not found in animal cells, although fungi, plant and animal cells are eukaryotic cells.

EUKARYOTIC vs PROKARYOTIC CELLS 1. Prokaryotes differ from eukaryotes in that prokaryotes Lack a Nucleus and Lack Membrane-Bound Organelles. 2. In place of a nucleus, prokaryotes have a region called a Nucleoid in which their genetic material is concentrated. 3. Prokaryotes lack an internal membrane system.

CELLS ORGANELLES w You are responsible to know all of the cells organelles. w You must be able to name, identify, and know the functions of them all w Read p and complete the structure function graph provided w THIS IS REVIEW FROM LAST YEAR w You will have a quiz on these next class!