f4 c2 cell structure.pptx

8/20/2019 F4 C2 Cell Structure.pptx

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CELLSTRUCTURE&


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Cell under light microscope


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Cell under electron microscopeNUCLEUS

NUCLEOLUSNUCLEAR

MEMBRANE

NUCLEOPLASM

RIBOSOME

PLASMAMEMBRANE

GOLGIAPPARATU

S

ROUGHENDOPLASMICRECTICULUM

SMOOTHENDOPLASMICRECTICULUM

LYSOSOME

CENTRIOLES

CYTOPLAS

M

MITOCHONDRI

A


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PLASMAMEMBRANE

- Refers to all membranes found inside the cell- Membrane that encloses the content of the cell- Is made of proteins and phospholipids

Functions:a) Separates the content of the cell from the outer

environment b) is semi-permeable and acts as selective barrier-

regulates the movement of substances into andout of the cytoplasm


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Cell wall

- rigid outer layer that surrounds theplasma membrane of plant cells

- composed of cellulose (tough and

fibrous carbohydrates)- is permeable to all fluids because it hastiny pores that allow substances to movefreely into and out of the cell


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Functions- gives shape to plant cell- provides mechanical support forthe plant cell

- protects the plant cell fromrupturing due to excessive intakeof water.


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CytoplasmConsists of a jelly li e matri! in "hich theorganelles of the cell are suspendedContains organic and inorganic substances

Functions #cts as a medium for biochemical reactions in

the cell

$rovides substances obtained from thee!ternal environment to the organelles


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Nucleus # large% dense spherical organelle enclosed

by a nuclear membraneContains nucleoplasm and nucleolus&ucleoplasm contains chromosomes "hich

carry genetic information that determine thecharacteristics and function of the cell

FunctionControls all the activities in the cell


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Endoplasmic reticul um

- # net"or of folded membranes forminginterconnected tubules or sacs- $hysically continuous "ith nuclearmembrane


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Rough endoplasmic reticulum- has ribosomes attached to its surface

Function transport proteins made b!ribosomes" Proteins from ER areenclosed in #esicles are sent to otherparts of the cell"

mooth endoplasmic reticulum - has no ribosomes attached to itssurfaceFunction site of important metabolicreactions$ and deto%i&cation of poisons

including drugs and s!nthesi'ing lipids


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RibosomesCompact spherical organelles foundattached to the surface of the roughendoplasmic or suspended freely in thecytoplasm'

(ach ribosome consists of t"osubunits% one small and one large'(ach subunit comprises a type of

ribonucleic acid R) and proteinFunctions:Synthesis of proteins such as en*yme


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- # stac offlattenedmembranous sacs

Function$rocess% pac age and tranport centre ofcarbohydrates% proteins and phospholipidsand glycoprotein

*olgi apparatus


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+) ,ransport vessicle carries protein from (R andfuse "ith the membrane "ith #'

.) ,ransport vessicle empties it content into #'


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+) Proteinsare modi&edas the! passthrough the*A",) *A sort

theseproducts andpac-ages

them into#esicles5) Vesicles will bu !" #$!% GA '($ el (! !(*e$ + $(s !# (*e cell !$ (!(*e +l s% %e%b$ 'e,) Vesicles #use wi(* +l s%


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Small spherical andc!lindrical shapeorganelles

Function.n#ol#ed in cellularrespiration"Cellular respiration

releases energ! when food substancesare bro-en down with the help ofen'!me in mitochondria"

Energ! released is stored in the form of

Mitochondrion


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Lens0shaped

Membranousstructure"Contains greenpigment calledc*l!$!+*/ll "

FunctionChloroph!ll traps sunlightand con#ert light energ! intochemical energ! during

photos!nthesis "

Chloroplast


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# sac filled "ith fluid calle cell sapIn plants% typical plant cell has large vacuole% small plant has numerous

smaller vacuoles' Functions:

#ct as food storage

place'Sap cell contains "ater% organic acids%

sugar% amino acids%mineral salts% "astesubstances% pigmentand metabolic by-products

1acuole


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.n unicellular organisms li-e paramecium$ ithas contractile #acuoles and food #acuoles0u'c(i!'Contractile #acuole 2 regulate waterbalance in the bod!Food #acuole- Pac-agefood to bedigested


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Function3) En'!me digest

comple% organicmolecules

(protein$

carboh!drate$lipids)4) Eliminate worn out

mitochondria andother

damagedorganelles so that

cells can renew

Membrane0boundsacsContainsh!drol!tic

en'!mes

L!sosome


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+) L!sosome fuses with food #acuolesand dispense en'!me into the#acuoles to digest the content of the#acuoles" /he nutrient released fromthe digestion is needed b! theorganisms

,) L!somes also digest bacteria b!


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CentriolesA pair of small c!lindrincal

structures located outsidethe nucleusComposed of a comple%

arrangement of microtubulesFunctionForm spindle &bres during cell di#isionin animal cells


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f4 c2 cell structure.pptx

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