CHAPTER 7 CELL STRUCTURE FUNCTION Biology I 102312

CHAPTER 7 CELL STRUCTURE & FUNCTION

Biology I – 10/23/12 Turn in Vocab Terms Microscope Lab Day 1 w. s

7. 2 Eukaryotic Cell Structure Objectives: Describe the function of the nucleus Describe the functions of the major cell organelles Identify the main roles of the cytoskeleton

7. 2 Eukaryotic Cell Structure q Cell organization Organelles q § § “little organs” the specialized structures within the cell that perform a function

Cytoplasm The fluid that fills the entire cell The portion of the cell outside of the nucleus In plants and animals

The Nucleus “Control center” of the cell Contains nearly all of the cell’s DNA &, with it, the coded instructions for making proteins and other important molecules In plants and animals

Inside the Nucleus Chromosomes Looks like granular material Contain genetic information/DNA

Inside the Nucleus

Inside the Nucleus Nucleolus Small, dense area in nucleus Directs the formation of ribosomes

Ribosomes q q q Small circles Make proteins Found in cytoplasm and on ER

Rough ER-looks like continuous tubes Has ribosomes on its surface Modifies proteins Produces proteins that will eventually leave the cell

Smooth ER No ribosomes Has enzymes makes membrane lipids & the detoxification of drugs

Golgi Apparatus Looks like a stack of flat pancakes Proteins produced in the rough ER move here Modifies, sorts, & packages materials from the ER

Lysosomes The “clean-up crew” Small organelles filled with enzymes Break down cellular materials

Lysosomes (cont) Found mostly in white blood cells Have been linked to diseases, such as Tay Sach’s is a disorder that is caused by a genetic defect that prevents the formation of an essential enzyme that breaks down lipids These lipids build up in the body and can cause nerve damage; prognosis is not good

Peroxisome Look like lysosomes Contains enzymes such as catalase Hydrogen peroxide is broken down here

Vacuoles Large sac-like, membrane enclosed structures Storage unit Larger in plant cells Pressure allows plants to support heavy structures

Mitochondria “Powerhouse” of the cell Creates cellular energy (ATP) for the cell to function

Chloroplasts Capture energy from the sun & convert it into chemical energy – photosynthesis! Where photosynthesis occurs Only in plant cells

Cytoskeleton helps cells keep its shape The framework of the cell Made up of microfilaments and microtubules

Cytoskeleton