Cells – The Basic Unit of LifeCells – The Basic Unit of Life

Types of CellsTypes of Cells

• There are many different types of cells, There are many different types of cells, which are specialized to carry our particular which are specialized to carry our particular functions.functions.

• Although they perform different functions, Although they perform different functions, cells have many common features.cells have many common features.

What are cells?What are cells?• Smallest structural and functional units of lifeSmallest structural and functional units of life

• Has the following characteristics of cells:Has the following characteristics of cells:• A LifespanA Lifespan• Can grow, reproduce and repair themselvesCan grow, reproduce and repair themselves• Can sense and respond to changes in their Can sense and respond to changes in their

environmentenvironment• Require energyRequire energy• Produce wasteProduce waste

INSIDE THE CELL:INSIDE THE CELL:ORGANELLES OF ANIMAL ORGANELLES OF ANIMAL

AND PLANT CELLSAND PLANT CELLS

Typical Plant Cell

Typical Animal Cell

Animal Cell vs. Plant CellAnimal Cell vs. Plant Cell

CELL MEMBRANECELL MEMBRANE

FUNCTION:FUNCTION:• SeparatesSeparates the inside of the cell the inside of the cell

from the outside environmentfrom the outside environment• ControlsControls flow of substances in and flow of substances in and

out of the cell (the “gatekeeper”)out of the cell (the “gatekeeper”)STRUCTURE:STRUCTURE:• Contains a Contains a phospholipid bilayerphospholipid bilayer that that

contains carbohydrate and proteinscontains carbohydrate and proteins

Cell MembraneCell Membrane

THE NUCLEUSTHE NUCLEUS

FUNCTION:FUNCTION:• The The ‘control ‘control

centre’ centre’ of the cellof the cell• DirectsDirects the cells the cells

activities activities (DNA)(DNA)STRUCTURE:STRUCTURE:• Membrane bound, Membrane bound,

dense structure dense structure found inside the found inside the cellcell

Zooming into the Zooming into the NucleusNucleus

MITOCHONDRIAMITOCHONDRIAFUNCTION:FUNCTION:• The The ‘power house’‘power house’• Site of Site of energyenergy production production• Releases energy from Releases energy from

glucoseglucose through process through process

calledcalled cellular respirationcellular respiration

STRUCTURE:STRUCTURE:• Oval shapedOval shaped• Folded inner membrane with Folded inner membrane with

finger like projectionsfinger like projections

RIBOSOMESRIBOSOMESFUNCTION:FUNCTION:• makes makes proteinprotein• They can be found:They can be found:

1.1. attachedattached (to RER) (to RER)

2.2. free-floating in free-floating in the cytoplasmthe cytoplasm

STRUCTURE:STRUCTURE:• Spherical shapeSpherical shape• Made of 2 subunitsMade of 2 subunits

Lysosomes Lysosomes (only Animal Cells)

FUNCTION:FUNCTION:• Known as the Known as the “suicide “suicide

sacs”sacs”• Contains Contains enzymesenzymes to to

destroy damaged cells destroy damaged cells and large moleculesand large molecules

STRUCTURE:STRUCTURE:• Small Small sacsac like structure like structure

ENDOPLASMIC RETICULUM ENDOPLASMIC RETICULUM (ER)(ER)

FUNCTION:FUNCTION:• Help Help transport transport

materials within materials within the cellthe cell

• Two types: Two types: Smooth ERSmooth ER and and Rough ERRough ER

ENDOPLASMIC ENDOPLASMIC RETICULUMRETICULUM

STRUCTURE:STRUCTURE:• Tubes that connect to the Tubes that connect to the

nucleus (‘subway/highway nucleus (‘subway/highway system’)system’)

Smooth ERSmooth ER• Contains no ribosomesContains no ribosomes• Lipid/Fat synthesis & Lipid/Fat synthesis &

transporttransport

Rough ERRough ER• Contains ribosomesContains ribosomes• Protein synthesis & Protein synthesis &

transporttransport

GOLGI APPARATUSGOLGI APPARATUS

FUNCTION:FUNCTION:• Stores, modifies and packages Stores, modifies and packages

proteinsproteins in small sacs called in small sacs called vesiclesvesicles• For transport outside of the cellFor transport outside of the cell

STRUCTURE:STRUCTURE:• Looks like stacked Looks like stacked pancakespancakes

VACUOLEVACUOLE

FUNCTION:FUNCTION:• StorageStorage and and supportsupport• Stores water, food & Stores water, food &

wasteswastes• Increases cell sizeIncreases cell size• Makes cell firmMakes cell firm

STRUCTURE:STRUCTURE:• Fluid filled spacesFluid filled spaces

Plant Cell Plant Cell CELL WALLCELL WALL

FUNCTION:FUNCTION:• Provides Provides structure structure

andand protection protection

STRUCTURE:STRUCTURE:• An additional An additional

coveringcovering in plants in plants outside of the cell outside of the cell membranemembrane

• Made of Made of cellulosecellulose

Plant Cell Plant Cell CHLOROPLASTCHLOROPLAST

FUNCTION:FUNCTION:• contains contains chlorophyllchlorophyll• Site of Site of photosynthesisphotosynthesis

STRUCTURE:STRUCTURE:• Double-membraned Double-membraned

organelle that organelle that contains stacked contains stacked discsdiscs

HomeworkHomework

• Read pages 52-60Read pages 52-60• Answer questions:Answer questions:

• #1-3, 5-6, 9 (on page 61)#1-3, 5-6, 9 (on page 61)

• Complete cell organelles chart Complete cell organelles chart and venn diagramsand venn diagrams