The Cell StructureThe Cell Structure

Ag BiologyAg Biology

Cell OverviewCell Overview

CELLS-The common thing that makes up CELLS-The common thing that makes up every living thing every living thing

Anton van Anton van LeeuwenhoekLeeuwenhoek was the first person was the first person to use a microscope to study nature.to use a microscope to study nature.

Robert Robert HookeHooke was the first to look at plant was the first to look at plant tissues under the microscope.tissues under the microscope.

Rudolf Rudolf VirchowVirchow studied cell reproduction and studied cell reproduction and declared that “Where a cell exists there must declared that “Where a cell exists there must have been a preexisting cell…”have been a preexisting cell…”

The Cell Theory States The Cell Theory States the Following:the Following:

All living things are composed of All living things are composed of cells.cells.

Cells are the basic units of structure Cells are the basic units of structure and function in living things.and function in living things.

New cells are produced from New cells are produced from existing cells.existing cells.

Basic Cell StructuresBasic Cell Structures

Micrometer (1,000 times smaller than a Micrometer (1,000 times smaller than a millimeter)millimeter)

The tiniest bacteria cells are only 0.2 The tiniest bacteria cells are only 0.2 micrometers.micrometers.

Typical cells range from 5-50 Typical cells range from 5-50 micrometers. micrometers.

Prokaryotic CellsProkaryotic Cells Prokaryotes – are Prokaryotes – are small and simplesmall and simple

have cell membranes and cytoplasmhave cell membranes and cytoplasm no nucleino nuclei all bacteria are prokaryotesall bacteria are prokaryotes they still grow, reproduce, and respond to they still grow, reproduce, and respond to

stimulistimuli

Eukaryotic CellEukaryotic Cell

they contain nuclei, and dozens of other they contain nuclei, and dozens of other structures called organellesstructures called organelles

but most are a part of a multicellular but most are a part of a multicellular systemsystem

PARTS OF A CELL-don’t PARTS OF A CELL-don’t writewrite

Structures within a cell are called Structures within a cell are called ORGANELLESORGANELLES

Have specific functions within the cell Have specific functions within the cell and structuresand structures

Carry out essential cell processesCarry out essential cell processes

NucleusNucleus

controls cell processes and contains DNA.controls cell processes and contains DNA. ChromatinChromatin – the visible material within the – the visible material within the

nucleus (form chromosomes)nucleus (form chromosomes) NucleolusNucleolus – within the nucleus, where – within the nucleus, where

ribosomes are maderibosomes are made Nuclear MembraneNuclear Membrane –surrounds the nucleus –surrounds the nucleus

and allows items to flow in/outand allows items to flow in/out

CytoskeletonCytoskeleton

network of protein network of protein filaments that helps the filaments that helps the cell maintain its shape.cell maintain its shape.

Involved in the Involved in the movement of the cell.movement of the cell.

Microtubules & Microtubules & MicrofilamentsMicrofilaments

RibosomesRibosomes Ribosomes are made of proteins and Ribosomes are made of proteins and

RNA (RiboNucleic Acid).RNA (RiboNucleic Acid). Produced in the nucleolusProduced in the nucleolus Some free floating, some attached to Some free floating, some attached to

endoplasmic reticulumendoplasmic reticulum

Endoplasmic ReticulumEndoplasmic Reticulum

Transport proteins out of the cellTransport proteins out of the cell Site of protein synthesisSite of protein synthesis The ‘rough ER’ has ribosomes on its surface, The ‘rough ER’ has ribosomes on its surface,

Smooth = no ribosomesSmooth = no ribosomes

Golgi ApparatusGolgi Apparatus

Proteins produced by the rough ER move Proteins produced by the rough ER move into the Golgi Apparatus.into the Golgi Apparatus.

Packages proteins into vesicles that can Packages proteins into vesicles that can be transported out or around the cell.be transported out or around the cell.

LysosomesLysosomes

““clean up crew”clean up crew” Digest bacteria/viruses/worn out Digest bacteria/viruses/worn out

organellesorganelles

CentrioleCentriole

Made of microtubulesMade of microtubules Found in cytoplasm near nucleusFound in cytoplasm near nucleus Aid in cell divisionAid in cell division

VacuolesVacuoles

Store water, salts, proteins, and carbs in Store water, salts, proteins, and carbs in saclike structures.saclike structures.

Plant cells usually have one large Plant cells usually have one large vacuole so the plant can support heavy vacuole so the plant can support heavy structures.structures.

MitochondriaMitochondria

““energy generator” or “powerhouse”energy generator” or “powerhouse” release energy from stored foods to release energy from stored foods to

make compounds that the cell can use to make compounds that the cell can use to power growth, development, and power growth, development, and movement.movement.

Cell Wall – Cell Wall – only in plant cellonly in plant cell

Not in animal cell.Not in animal cell. made from fibers making a tough substance made from fibers making a tough substance

called cellulose.called cellulose. provides protection and support for the cell.provides protection and support for the cell.

Chloroplasts – Chloroplasts – plant cell plant cell onlyonly

Use energy from the sun to make energy Use energy from the sun to make energy rich food.rich food. AKA photosynthesis.AKA photosynthesis.

Activity!Activity!

Fill out the worksheet on the parts of the cell Fill out the worksheet on the parts of the cell and be thinking about how you could turn all of and be thinking about how you could turn all of these cell parts into a self sustaining city.these cell parts into a self sustaining city.

You get to make a…You get to make a… Cell City!Cell City!