1. Cell Structure and Function.pptx

7/25/2019 1. Cell Structure and Function.pptx

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Cell Structure and

Function


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Concepts of the Cell Theory

A cell is the basicstructural and functional

unitof living organisms.The activity of anorganism depends on thecollective activities of itscells.


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Concepts of the Cell Theory

According to theprincipleof complementarity, the

biochemical activities ofcells are dictated by therelative number of their

specic subcellularstructures.

Continuity of life has a


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Chemical Components of Cells

Most cells are composedof the following four

elementsCarbon

Hydrogen!ygen

"itrogen


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Cells and Tissues

Carry out all chemicalactivities needed to

sustain life Cells are the building

bloc#s of all livingthings.

Tissues are groups of


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Anatomy of the Cell

Cells are not all the same. All cells share generalstructures.

All cells have three main regions

"ucleus

Cytoplasm$lasma membrane


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Anatomy of the Cell

The nucleoplasm andcytosol ma#e up the

intracellular %uid.


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Nucleus

Cytoplasm

Plasmamembrane

(a)


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The "ucleus

Control center of the cellContains genetic material&'"A(

Three regions

"uclear envelope &membrane(

"ucleolus

Chromatin


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Nucleus

Nuclear envelope

Chromatin

Nuclearpores

Nucleolus

Rough ER

(b) Figure 3.1b


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The "ucleus

"uclear envelope &membrane()arrier of the nucleus

Consists of a doublemembrane

Contains nuclear pores that

allow for e!change of materialwith the rest of the cell


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The "ucleus

"ucleoli"ucleus contains one or

more nucleoliSites of ribosomeassembly

*ibosomes migrate intothe cytoplasm through

nuclear ores


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The "ucleus

Chromatin

Composed of DNA andprotein

$resent when the cell isnot dividing

Scattered throughout thenucleus

Condensesto form


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$lasma Membrane

)arrier for cell contents Double phospholipid

layerHydrophilic heads

Hydrophobic tails Also contains proteins,

cholesterol, and


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$lasma Membrane

Glycoproteins-Themolecules that ma#e the

cell surface fu++y, stic#y,and sugar-rich


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$lasma Membrane

A( it consists of two lipid layers

)( its lipid components areprimarily phospholipids and

cholesterolC( it contains proteins for

speciali+ed functions

'( it regulates the entry and e!itof cell materials

( it does not allows watersoluble molecules to ass


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Figure 3.2

Extracellular uid(watery environment)

ugargroup

Polar hea!s o"phospholipi!molecules

#imolecularlipi! layercontainingproteins

Nonpolar tails

o" phospholipi!molecules

$lycoprotein

Proteins Filaments o"

cytos%eleton Cytoplasm(watery environment)

Channel

Cholesterol

/lycolipid


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$lasma Membrane 0unctions

Membrane 1unctions2. Tight 1unctions

3. 'esmosomes4. /ap 1unctions


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Membrane 1unctions2. Tight 1unctions

5mpermeable 1unctions

)ind cells together into

lea#proof sheets membrane connections

that prevent the lea#ing of

%uid between cells


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Plasmamembranes o"a!&acent cells

'esmosome(anchoring

&unction)

ight(impermeable)&unction

icrovilli

$ap(communicating)

&unction

E*tracellularspace bet+een

cells

,n!erlyingbasement

membrane

Conne*on

Figure 3.3


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Membrane 1unctions3. 'esmosomes

Anchoring 1unctions thatprevent cells from beingpulled apart


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'esmosome(anchoring

&unction)


icrovilli

$ap(communicating)

&unction


cells

,n!erlyingbasement

membrane

Conne*on

Figure 3.3


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Membrane 1unctions4. /ap 1unctions

Allow communicationbetween cells

Allows Nutrients andions pass directly

from cell to cell


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'esmosome(anchoring

&unction)


icrovilli

$ap(communicating)

&unction


cells

,n!erlyingbasement

membrane

Conne*on

Figure 3.3

C t l


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Cytoplasm

The material outsidethe nucleus and inside

the plasma membraneSite of most cellular

activities

C t l


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Cytoplasm

Contains threema1or elements

2.Cytosol

3.rganelle4.5nclusions


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Cytoplasm

Contains three ma1orelements

2. CytosolFluid that suspends

other elements


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Cytoplasm


3. rganellesMetabolic machineryof the cell

67ittle organs8 thatperform functions for


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Cytoplasm


3. rganellesThe speciali+ed cellularcompartments withinthe cytosol of the cell


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Cytoplasm


4. 5nclusionsChemical

substances such asstored nutrients or

Chromatin


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Ribosomes

$olgi apparatus

ecretion being release!

"rom cell by e*ocytosisicrotubule

Centrioles

itochon!rion

-ysosome

Cytosol

mooth en!oplasmicreticulum

Chromatin

Nucleolus

Nuclear envelope

Nucleus

Plasmamembrane

Roughen!oplasmicreticulum

5ntermediate

laments

$ero!isome

Figure 3.

C t l i ll


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Cytoplasmic rganelles

Mitochondria6$owerhouses8 of the cell

Change shapecontinuously

Carry out reactions whereo!ygen is used to brea#down food


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*ibosomesMade of protein and

*"ASites of proteinsynthesis

Found at two locations

Free in the


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ndoplasmic reticulum &*(

Fluid-lled tubules forcarrying substances

Two types of *

2. Rough endoplasmic

reticulumStudded with ribosomes

Synthesi+es proteins


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ndoplasmic reticulum&*(

Two types of *

3. moothendoplasmic

reticulumFunctions in lipid

metabolism and


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Figure 3./

0n the cistern the protein "ol!s into its"unctional shape. hort sugar chainsmay be attache! to the protein ("orminga glycoprotein).

he protein is pac%age! in a tinymembranous sac calle! a transportvesicle.

he transport vesicle bu!s "rom therough ER an! travels to the $olgiapparatus "or "urther processing.

s the protein is synthesie! on theribosome it migrates into the rough ERcistern.

32

1

Ribosome mRN

Rough ER

ransportvesicle bu!s o""

Protein insi!etransport vesicle

Protein

3

2

1


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Figure 3./ step 1

Ribosome mRN

Rough ER

Protein


1

1


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Figure 3./ step 2



2

Ribosome mRN

Rough ER

Protein

21

1


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Figure 3./ step 3




32

1

Ribosome mRN

Rough ER


Protein

3

2

1


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Figure 3./ step



he transport vesicle bu!s "rom therough ER an! travels to the $olgiapparatus "or "urther processing.


32

1

Ribosome mRN

Rough ER


Protein insi!etransport vesicle

Protein

3

2

1


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Golgi apparatusModies and pac#ages

proteins$roduces di9erent typesof pac#ages

ecretory vesicles

Cell membrane


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Figure 3.4

$olgi vesicle containing!igestive enymesbecomes a lysosome

Path+ay 3

Path+ay 2

ecretory vesicles

Proteins

ecretion bye*ocytosis

$olgi vesicle containingproteins to be secrete!becomes a secretoryvesicle

$olgiapparatus

Path+ay 1

ransportvesicle

embrane

Proteins in cisternaCisternaRough ER

-ysosome "uses +ith

ingeste! substances

$olgi vesicle containingmembrane components"uses +ith the plasma

membrane

Plasma membrane

Extracellular fluid


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7ysosomesContain en+ymes

produced by ribosomes$ac#aged and secretedby the /olgi apparatus

'igest worn-out ornonusable materials

within the cell


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$ero!isomesMembranous sacs ofo!idase en+ymes

'eto!ify harmfulsubstances such as

alcohol and formaldehyde)rea# down free radicals&highly reactive chemicals(


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Cytoplasmic rganelles Cytos#eleton

"etwor# of protein structuresthat e!tend throughout thecytoplasm

$rovides the cell with aninternal framewor#

Three di9erent types ofelements

Microlaments &largest(


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Figure 3.5a6c

(a) icro"ilaments (b) 0nterme!iate "ilaments (c) icrotubules

ctin subunit

5 nm 17 nm

Fibrous subunits ubulin subunits

2/ nm

icro"ilaments "orm the bluenet+or% surroun!ing the pin%nucleus.

0nterme!iate "ilaments "ormthe purple batli%e net+or%.

icrotubules appear as gol!net+or%s surroun!ing thecells8 pin% nuclei.

l i ll


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Centrioles*od-shaped bodies

made ofmicrotubules

'irect the formationof mitotic spindle

C ll l 1 i


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Cellular $ro1ections

"ot found in all cells

Ciliamove materialsacross the cell surface

7ocated in the respiratorysystem to move mucus

"lagellapropel the cell

The only %agellated cellin the human body is

sperm

C ll l $ 1 i


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Cellular $ro1ections

"ot found in all cells

#icrovilliare tiny,ngerli#e e!tensions of

the plasma membrane5ncrease surface area

for absorption


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Figure 3.9a

Fibroblasts

Rough ER an! $olgiapparatus No organelles

Nucleus

Erythrocytes

(a) Cells that connect bo!y parts


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Figure 3.9b

Epithelialcells

Nucleus

0nterme!iate

"ilaments

(b) Cells that cover an! line bo!y organs


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Figure 3.9c

%eletalmuscle cell

Nuclei

Contractile

"ilaments

mooth

muscle cells

(c) Cells that move organs an! bo!y parts


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Figure 3.9!

Fat cell -ipi! !roplet

(!) Cell that stores

nutrients

Nucleus

-ysosomes


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-ysosomes

acrophage

(e) Cell that "ights

!isease

Pseu!o6po!s

Figure 3.9e


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Figure 3.9"

ProcessesRough ER

Nerve cell

Nucleus

(") Cell that gathers in"ormation an! controls bo!y "unctions


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Nucleus Flagellum

perm

(g) Cell o" repro!uction

1. Cell Structure and Function.pptx

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