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  Cell organization  Organelles  “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

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

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

Ribosomes  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

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

Lysosomes (cont)  Found mostly in white blood cells  Have been linked to diseases, such as Tay Sach’s  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