CELL: Structure & Function

Objectives:

– Explain why a cell is like a tiny factory.

– List, label, and describe the functions of the parts of a typical eukaryotic animal cell.

– Explain how a cell conducts all the processes of living things, just on a smaller scale.

What You Need To Run A Factory

• building• supports/ internal framework• control center• blueprints• power plant• raw materials• machines/ workers• assembly line• packing centers• packing/ boxes• trucks/ shipping vehicles• waste disposal

Cell:A cell is the smallest unit that is capable of performing life functions.

Prokaryotic

• Do not have structures surrounded by membranes

• Few internal structures• 1-celled organisms,

Bacteria

http://library.thinkquest.org/C004535/prokaryotic_cells.html

Eukaryotic• Contain organelles surrounded by membranes• Most living organisms

Plant Animal

http://library.thinkquest.org/C004535/eukaryotic_cells.html

Cell/Plasma Membrane“Building”

• Outer membrane of cell that controls nutrient and waster material movement in and out of the cell

• Double layer of lipid & protein separating cell from its environments

• All cells have one

http://library.thinkquest.org/12413/structures.html

Cell Wall

• Most commonly found in plant cells & bacteria

• Supports & protects cells

http://library.thinkquest.org/12413/structures.html

Nucleus“control center”

• Controls the cell’s actions• Contains the cell’s genetic material (DNA).• Surrounded by a double membrane called the nuclear

envelope/membrane• Has a dense region called the nucleolus where ribosomes are

formed.

© Glencoe Biology 2007

Chromatin“blueprints”

• Located in the nucleus• Composed of nucleic acids

(DNA)• Condenses into chromosomes

during cell division• Contain instructions for traits

& characteristics Chromosomes during early cell division – 10,000x

Cytoskeleton“supports & internal framework”

• A network of protein fibers (microfilaments) and tubes (microtubules) extending throughout the cell.– Provides a framework for the cell.– Helps transport materials.– Anchors the organelles.– Functions in cell movement

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lencoe Biology 2007

• Organelles that manufacture proteins• Composed of RNA and protein• Not bound by a membrane.• Some float free in the cytoplasm while others are

attached to the endoplasmic reticulum.

Ribosomes- “machines/ workers”

Electron Micrograph of ribosomes. The ribosomes operate in chains when translating a mRNA.

Copyright © Daniel Kunkel

http://library.thinkquest.org/12413/structures.html

Golgi Apparatus“packing plant”

• A series of flat, membrane-bound sacs that sorts, modifies, packages, and distributes molecules into sacs called vesicles.

© Glencoe Biology 2007

http://library.thinkquest.org/12413/structures.html

Lysosomes“waste disposal”

• Special vesicles that contain powerful digestive enzymes that can break down large molecules and old organelles.

• Cell breaks down if lysosome explodes

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http://library.thinkquest.org/12413/structures.html

The Discovery of the Cell-1665: Robert Hooke used an early compound microscope to look at

a thin slice of cork, a plant material.

-Cork looked like thousands of tiny, empty chambers…“cells”

Idea: The cell is the basic unit of life basic

The Discovery of the Cell

• Anton van Leeuwenhoek: used a single-lens microscope to observe pond water and other things.

• The microscope revealed a world of tiny living organisms.

Cell Theory

All living things are made up of cells

Cells are the smallest working units of all living things

All cells come from preexisting cells through cell division

Structure of the Plasma Membrane• Composed of a phospholipid bilayer

© Glencoe Biology 2007

Fluid Mosaic Model

© Glencoe Biology 2007