Chapter 7 Cell Structure

Chapter 7 Cell Structure

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Chapter 7 Vocabulary1. Cell wall-Strong supportive layer found on

the outside outside of the cell membrane.membrane.2. Cell membrane- Thin flexible layer

surroundingsurrounding the cell; controls what entersenters or leaves the cell.

3. Chloroplasts-Organelle found in plant plant cells that capture energy from sunlightsunlight and converts it into chemical energy.energy.

4. Eukaryote-a cell with a nucleusnucleus and organelles.organelles.

Vocab

5. Ribosome—Organelle that makes proteinprotein6.Mitochondrion-powerhousepowerhouse of the cell; converts chemical energy into a form more usable by the cell (ATP)7. Prokaryote- a cell that lackslacks a nucleus or organelles (bacterial bacterial cells).8. Phospholipid- molecule that make up cell cell membrane. membrane.

9. Organelle- structure inside the cell that carries out a specificspecific function.

10. Selectively Permeable-property of cell membranesmembranes that allows certain things to enterenter the cell while others cannot enter cannot enter the cell.

11. Cell theory-Concept of biologybiology that states all living things are made of cells cells and all cells come from pre-existingpre-existing cells.

Animal Cell

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1.

2.

3.

4.

5.6.

7.

8.

9.

10.

Animal Cell

• 1. Mitochondria• 2. cell membrane• 3. Ribosome• 4. Centrioles• 5. Golgi Body• 6. Lysosome• 7. Rough Endoplasmic

Reticulum (ER)

• 8. Nucleus• 9. Smooth Endoplasmic

Reticulum (ER)• 10. Cytoplasm

Plant Cell

1.

2.

3.

4.

5. 6.

7.

8.

9.

10.

Plant Cell

• 7. Cell Membrane• 8. Cytoplasm• 9. Central Vacuole• 10. Smooth ER

• 1. Nucleus• 2. Rough ER and

Ribosomes• 3. Mitochondria• 4. Golgi Body• 5. Chloroplasts• 6. Cell Wall

7-1 Objectives

• List the three parts of the cell theory.• Determine why cells have to be relatively

small.• Compare the structure of prokaryotic cells to

that of eukaryotic cells.

• Robert Hooke – Looked at non-living cells in cork

using a crude microscope in 1665– Called them cells because they

reminded him of a monk’s room

• Anton van Leeuwenhoek– First to observe living living organisms

(in pond water and bacteria from his own mouth)

http://askabiologist.asu.edu/research/buildingblocks/images/hookecorkS.jpg

http://www.arsmachina.com/images/hooke.jpg

Discovery of Cells

Cell Theory1. All living things are

made up of cells

2. Cells are the basic units of structurestructure and functionfunction in organisms

3. All cells arise from other livingliving cells

http://peer.tamu.edu/curriculum_modules/Cell_Biology/module_1/levels%20of%20organization.jpg

Why are cells small? Why can’t I have a cell the size of a minivan?

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Cells Must Be Small• All substances that

enter or leave the cell must cross the cell’s surface

• The cell needs to maintain a high surface area to volume ratio

• Large cells cannot take in nutrientsnutrients and get rid of wastewaste fast enough for the cell to survive.

http://library.thinkquest.org/C006669/media/Biol/img/surface_area_to_volume_ratio.gif

Common Features of All Cells1. Cell membrane

A. keeps cell conditions different from outside environment

B. regulates what enters enters or leaves tleaves the cell

2. CytoplasmA. inside the cell cell

membranemembrane and outside the nucleusnucleus

B. Jell-O like substancehttp://www.daylilies.org/ahs_dictionary/cytoplasm.gif

Common Features of All Cells

3. CytoskeletonA. SupportSupport for organelles

4. Ribosomes A. Help make proteinsproteins

http://www.uic.edu/classes/bios/bios100/lecturesf04am/cytoskeleton.jpg

Prokaryotic vs Eukaryotic

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Prokaryotic cells do not contain internal compartments

ProkaryotesA. No nucleus nucleus and no

compartments

B. 3.5 billion 3.5 billion years old

http://english.pravda.ru/img/2005/11/bacteria.jpg

Eukaryotic cells are well organized

EukaryotesA. Have a nucleus which

holds DNADNA

B. Organelles . Organelles carry out specific activities

Prokaryotes Eukaryotes

7-1 Review Questions1. Why do cells have to be small?2. Name four structures that are common to

all cells.3. What is the difference between a

prokaryotic and eukaryotic cell?

7-2 Objectives

• Describe the role of the nucleus in cell activities.

• Analyze the importance of cell organelles in protein production.

• Summarize the importance of mitochondria in eukaryotic cells.

• Identify three structures in plant cells that are absent in plant cells.

How is a cell like a factory?

Directs All Cell Activities and Stores DNA

1. Nuclear envelope – surroundssurrounds nucleus

2. Nuclear pores – helps substances move into and out of the nucleus

http://spectorlab.cshl.edu/images/NucleusModel.jpg

Nucleus – “The Boss”

DNA (“Blueprint”) is Stored in the Nucleus

A. When the cell is not dividing – chromatinchromatin

B. When cell is dividing – condenses into chromosomeschromosomes

http://homepage.smc.edu/hgp/images/cell-to-DNA.jpeg

The Cell Membrane – “Security”

http://sun.menloschool.org/~cweaver/cells/c/cell_membrane/fluid_mosaic.jpg

Controls what enters and leaves the cell

A.A. SelectivelySelectively Permeable = only lets certain things through

B. Proteins in the membrane “check “check ID”ID”

Production of Proteins – “Manufacturing”

1. Ribosomes– Make proteins that remain remain

in the cell

2. Rough Endoplasmic Reticulum (ER) – Makes proteins that are

exportedexported from the cell or to specialized organelles

http://micro.magnet.fsu.edu/cells/endoplasmicreticulum/images/endoplasmicreticulumfigure1.jpg

3. Smooth ER – no ribosomesribosomes– makes lipids and

breaks down toxins

• Vesicles (“Mail Carriers”) – membrane bound sacs that transport transport proteins

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“Manufacturing”

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Golgi Apparatus“Customization and Shipping”

1. Proteins made in the Rough ER move to Golgi apparatus

2. Enzymes modify modify the proteins

3. Then they are enclosed in a new vesiclevesicle for transport http://www.mie.utoronto.ca/labs/lcdlab/biopic/fig/4.12.jpg

Gets proteins ready for transport

Lysosomes – “Maintenance”

A. Made by Golgi apparatus

B. Contain enzymes enzymes for digestion

C. RecycleRecycle a cell’s used parts

http://sun.menloschool.org/~cweaver/cells/e/lysosomes/brittanica.jpg

http://student.ccbcmd.edu/~gkaiser/biotutorials/eustruct/images/phagocyt.gif

Lysosomes – “Maintenance”Function in digestion and waste removal

Mitochondria – “The Powerhouse”

A. Inner membrane is highly folded– creates more surface surface

areaarea– many complex

chemical reactions occur here

B. Muscle cells Muscle cells have a lot of mitochondria

http://www.octc.kctcs.edu/gcaplan/anat/images/Image337.gif

Converts sugar to energy (ATP)

Mitochondria – “The Powerhouse”

http://micro.magnet.fsu.edu/cells/mitochondria/images/mitochondriafigure1.jpg

Mitochondria and Chloroplasts have their own DNA!

Mitochondrial DNA• Inherited through

mother

• Mitochondria could once have been free-free-living organisms

=> Endosymbiosis1) can explain the origins

of eukaryotic cells2) one small cell came to

live inside another http://www.accessexcellence.org/RC/AB/WYW/lander/images/inheritance_chart.gif

Endosymbiosis

http://www.sirinet.net/~jgjohnso/endosymbiosis.jpg

Plants cells have certain structures that Animal cells lack

1. Cell Wall

A. Supports and protects

B. Contains cellulosecellulose

http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG

2. Chloroplasts – “Solar Power!”

A. Found in plants and green algae

B. Like mitochondria, contain their own DNADNA

http://micro.magnet.fsu.edu/cells/chloroplasts/images/chloroplastsfigure1.jpg

Converts sunlight into carbohydrates

3. Central Vacuole – “Storage”

A. When full, makes cell rigidrigid

B. Enables plants to stand upright

http://www.progressivegardens.com/knowledge_tree/plantcell.jpg

Stores water and other substances

Review Questions1. What is the difference between Rough

and Smooth ER?2. What is the function of mitochondria?3. Which cell organelle is the shipping and

packaging center for the cell?4. What are the functions of lysosomes?5. Why do mitochondria and chloroplasts

have their own DNA?6. Name three structures found in plant cells

that are not found in animal cells