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

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