Prokaryotes Vs. Prokaryotes Vs. EukaryotesEukaryotes

There are 2 main types of cells:There are 2 main types of cells: Prokaryotes:Prokaryotes: - have no membrane- - have no membrane-

bound nucleus or organelles bound nucleus or organelles – Usually very small 0.0005 – 0.001mmUsually very small 0.0005 – 0.001mm

Eukaryotes:Eukaryotes: - have membrane- - have membrane-bound nucleus and organelles bound nucleus and organelles – Usually from 0.01 – 0.1mmUsually from 0.01 – 0.1mm– Often complexOften complex– Often specialisedOften specialised

Type Type of cellof cell

AnimAnimalal

PlantPlant FunguFunguss

ProtisProtistt

BacteriuBacteriumm

ViruViruss

P Vs. P Vs. EE

EukaryoteEukaryote ProkaryotProkaryotee

Not Not living.living.

Must Must invade invade other other cells cells to to survivsurvivee

not not really really a cell a cell type. type. CannoCannot live t live on its on its own.own.

NucleuNucleuss

YesYes No, No, nuceloid nuceloid

OrganelleOrganelless YesYes NoNo

Cell Cell WallWall

NoNo YesYes YesYes SomeSome YesYes

Cell Cell MembranMembranee

YesYes

OrganellesOrganelles

Organelles are structures within Organelles are structures within the cell that are enclosed by a the cell that are enclosed by a membranemembrane

They can be described as They can be described as compartments within a cellcompartments within a cell

They carry out specific functionsThey carry out specific functions Because they are enclosed by Because they are enclosed by

membranes, organelles can membranes, organelles can maintain conditions which are very maintain conditions which are very different to other parts of the celldifferent to other parts of the cell

NucleusNucleus

The nucleus contains the DNA The nucleus contains the DNA It is enclosed by membrane It is enclosed by membrane

sometimes called the nuclear sometimes called the nuclear envelopeenvelope

This membrane has pores/spaces This membrane has pores/spaces through which certain substances through which certain substances (such as mRNA) can pass in/out of(such as mRNA) can pass in/out of

The DNA inside forms a template The DNA inside forms a template for protein productionfor protein production

NucleusNucleus

The nucleus controls the The nucleus controls the functioning of the cell: functioning of the cell: – Cell division Cell division – Protein productionProtein production– Apoptosis (programmed cell-death)Apoptosis (programmed cell-death)

Within the nucleus are many large Within the nucleus are many large clumps which appear as dark clumps which appear as dark spots under the microscope. spots under the microscope. These are These are nucleoli (nucleolus nucleoli (nucleolus sing.) sing.)

The nucleoli are clumps of RNA The nucleoli are clumps of RNA moleculesmolecules

Nucleoli

Nuclear Membrane

Nuclear Pores

RibosomesRibosomes

Produce protein for the cell by Produce protein for the cell by using DNA as a templateusing DNA as a template

These are not membrane-bound These are not membrane-bound not true organellesnot true organelles

All cells have them (even All cells have them (even prokaroytes)prokaroytes)

Cannot be seen without an electron Cannot be seen without an electron microscope or specialised stainingmicroscope or specialised staining

Made up of rRNA and other proteinsMade up of rRNA and other proteins

Endoplasmic reticulumEndoplasmic reticulum

A series of membrane-bound A series of membrane-bound channels. Its main function is channels. Its main function is transport of substances within the transport of substances within the cell.cell.

There are 2 types:There are 2 types:– Rough (RER): has ribosomes on the Rough (RER): has ribosomes on the

surface, found surrounding the nucleus surface, found surrounding the nucleus – Function is to produce proteins and Function is to produce proteins and

modify them for transportationmodify them for transportation

– Smooth (SER): - also found surrounding Smooth (SER): - also found surrounding nucleus, often joined to RERnucleus, often joined to RER

– Function is to remove toxins/de-activate Function is to remove toxins/de-activate themthem

Golgi Body Golgi Body

Also called Golgi complex or Golgi Also called Golgi complex or Golgi apparatusapparatus

Consists of stacks of membrane- Consists of stacks of membrane- bound sacksbound sacks

Functions to package and Functions to package and transport proteins and lipids for transport proteins and lipids for export into export into secretory vesiclessecretory vesicles which can pass out of the cell which can pass out of the cell membrane easilymembrane easily

Secretory vesicles

ChloroplastsChloroplasts Produce energy for the cellProduce energy for the cell Contain Contain chlorophyllchlorophyll in the grana in the grana Chlorphylyll is an enzyme which traps Chlorphylyll is an enzyme which traps

the energy from sunlight for use in the energy from sunlight for use in sugar productions (photosynthesis)sugar productions (photosynthesis)

Chlorophyll is also a pigment which is Chlorophyll is also a pigment which is green in colourgreen in colour

Plant cells (and some fungi) contain Plant cells (and some fungi) contain chloroplastschloroplasts

These organelles are often large These organelles are often large enough to see with the light enough to see with the light microscope and contain small microscope and contain small amounts of DNAamounts of DNA

External membrane

Inner membrane

Grana

Stroma

MitochondriaMitochondria

Convert the energy obtained from Convert the energy obtained from food (glucose) to a form that the food (glucose) to a form that the cell can use (ATP) using Ocell can use (ATP) using O22

This process is called cellular This process is called cellular respirationrespiration

Mitochondria also contain small Mitochondria also contain small amounts of DNA amounts of DNA

All cells except Monera have theseAll cells except Monera have these

VacuolesVacuoles

The main functions of vacuoles The main functions of vacuoles are to store substances such as are to store substances such as food in an environment which food in an environment which is separate to the cytoplasmis separate to the cytoplasm– Eg foodEg food

Other specialised vacuoles Other specialised vacuoles store substances which may store substances which may pose danger to the cellpose danger to the cell

Lysosomes, Lysosomes, PeroxisomesPeroxisomes LysosomesLysosomes contain destructive contain destructive

enzymes which can break down enzymes which can break down damaged or old cell parts and damaged or old cell parts and moleculesmolecules

PeroxisomesPeroxisomes contain enzymes which contain enzymes which break down hydrogen peroxide break down hydrogen peroxide (H(H22OO22) which is a product of many ) which is a product of many biochemical reactions and can be biochemical reactions and can be highly toxic and damaging to cellshighly toxic and damaging to cells

CytoplasmCytoplasm

The fluid component of the cellThe fluid component of the cell

Also called the cytosol or cytogelAlso called the cytosol or cytogel

It contains dissolved minerals, It contains dissolved minerals, proteins, enzymes, sugars, salts, proteins, enzymes, sugars, salts, lipids and the organelleslipids and the organelles

It provides the perfect environment It provides the perfect environment for chemical reactionsfor chemical reactions

CytoskeletonCytoskeleton

This is an internal framework This is an internal framework of proteins which supply of proteins which supply structure and support to the structure and support to the cell and allow movement of cell and allow movement of the cell and the organelles the cell and the organelles withinwithin

Cell MembraneCell Membrane

Also called the Plasma Also called the Plasma Membrane or PlasmalemmaMembrane or Plasmalemma

Function is to control the Function is to control the movement of substances into movement of substances into and out of the celland out of the cell

All cells have one!!All cells have one!!

Cell WallCell Wall

Not found in animal cellsNot found in animal cells

Plays an very important role in Plays an very important role in structural support of the cellstructural support of the cell

Prevents the cells from bursting Prevents the cells from bursting due to water absorptiondue to water absorption

Found in bacteria, fungi, plants Found in bacteria, fungi, plants and some protistsand some protists

Nucleus

Mitochondrion

Animal Cell

Endoplasmic reticulum

Golgi body

Cell Membran

e

Cytoplasm