1. Chapter 3 Cell Structure and Function

2. Animal Cell 1. cell (plasma) membrane – thin, transparent, 2-layered, semi-permeable (porous), flexible -controls what enters and leaves cell -separates cell from its environment

3. 2.nucleus – command center of the cell; most cells have only one; some have >1 DNA: a) chromatin – mass of fibers scattered through the nucleus (thread-like) b) chromosomes – compact chromatin -direct & store instructions for all cell functions -control inheritance of traits

4. c) nuclear membrane – 2-layered, semi-permeable, porous, surrounds nucleus d) nucleolus – cell may have 1 or 2; produce granules rich in RNA, each granule will become part of a ribosome e) nucleoplasm - fluid within the nucleus

5. * 3. cytoplasm – jelly-like fluid outside nucleus, but within cell -transports chemical substances within the cell 4. endoplasmic reticulum – network of interconnected membranes (ER) -storage, separation, and transport of substances made within the cell (mostly proteins) a) rough ER – dotted with ribosomes b) smooth ER – no ribosomes

6. 5. Golgi apparatus (body) – stack of flattened membranes where proteins are packaged and distributed 6. vacuole – clear, fluid-filled sac; used for storage 7. lysosome – small sac filled with powerful chemicals which break down food molecules and digest old organelles; surrounded by a membrane

7. 8. mitochondria – “powerhouse” of the cell; bean-shaped; one of the largest and most numerous; site of cellular respiration Cytoskeleton 9. microtubules – long, thin, hollow cylinders; in cytoplasm, they support cell (shape) or are arranged in bundles in other structures (like cilia, flagella, or centrioles* - only in animal cells) 10. microfilaments – tiny-threadlike fibers made of protein; contract like muscle cells for movement

8. 11. ribosomes – tiny, round bodies involved in protein synthesis from amino acids

9. Plant Cell -have a cell wall composed of cellulose (provides structure and support) -contain chloroplasts – function in photosynthesis (football shaped), starch granules – spherical, function in food storage, and carotens – contain orange pigments; spherical -plant cells are rectangular in shape (animal cells are spherical) -have a large water vacuole which provides turgor pressure