A tour of the CellA tour of the Cell

Chapter 7Chapter 7http://www.youtube.com/watch?http://www.youtube.com/watch?v=o1GQyciJaTA&feature=relatedv=o1GQyciJaTA&feature=related

http://www.ibiblio.org/virtualcell/textbook/chapter3/http://www.ibiblio.org/virtualcell/textbook/chapter3/chapter3.htmchapter3.htm

http://vcell.ndsu.edu/animations/http://vcell.ndsu.edu/animations/

Cell theoryCell theoryAll living things are composed All living things are composed

of cellsof cellsCells are the basic unit of Cells are the basic unit of

function and structure in living function and structure in living thingsthings

All cells come from pre-existing All cells come from pre-existing cellscells

Eukaryotic vs. Eukaryotic vs. prokaryoticprokaryotic

cellscells Contains nucleusContains nucleus Many organelles Many organelles

presentpresent 10-100 10-100

micrometersmicrometers Appeared later in Appeared later in

the fossil recordthe fossil record

Lacks a nucleusLacks a nucleus Lacks organellesLacks organelles

1-10 1-10 micrometersmicrometers

Appeared earlier Appeared earlier in the fossil in the fossil recordrecord

Two Basic types Two Basic types Cell membrane

cytoplasm

Cell membrane

cytoplasm

nucleus

Cell organelles

Prokaryote

Eukaryote

Prokaryotes Eukaryotes

Cell membraneRibosomes

NucleusEndoplasmic reticulumGolgi apparatusLysosomesVacuolesMitochondriaCytoskeleton

Compare and Contrast

Page 206Page 206

Compare/contrast plant and Compare/contrast plant and animal cellsanimal cells

Plant cell Animal cell

Cell wallLarge vacuole

chloroplast

Centriolesflagellum

ribosomesmitochondria

Endoplasmic reticulum

nucleus

Golgi apparatus

Cell membrane

Cell MembraneComposed of proteins and a

type of lipid called phospholipid

The structure that makes the plasma membrane is called the phospholipid bilayer

http://www.wisc-online.com/Objects/construction-of-the-cell-membrane/http://www.wisc-online.com/Objects/construction-of-the-cell-membrane/

Phospholipid molecule of Plasma Membrane

Plasma Membrane Structure

Ways cells get molecules Ways cells get molecules in and out of cellin and out of cell

No cell energy usedNo cell energy used

DiffusionDiffusion

Facilitated diffusionFacilitated diffusion

Cell energy usedCell energy used

Active transportActive transport

http://www.wisc-online.com/Objects/construction-of-the-cell-http://www.wisc-online.com/Objects/construction-of-the-cell-membrane/membrane/

DiffusionThe net movement of particles

of a substance from where they are more concentrated to where they are less concentrated

DiffusionDiffusion

The random movement of molecules The random movement of molecules from a high concentration to a low from a high concentration to a low concentrationconcentration

If system is left alone the molecules If system is left alone the molecules will eventually spread themselves will eventually spread themselves equally every where – the molecules equally every where – the molecules do not stop moving throughdo not stop moving through

Types of Transport through plasma

membrane Passive transport– Diffusion: some molecules cross the

plasma membrane with no expenditure of energy or help from transport proteins

Osmosis: diffusion of water through a membrane

– Facilitated diffusion: Transport proteins provide a pathway for certain molecules to pass

Active transport

Water moves from high concentration to low concentration

What happens to a red blood cell when it is What happens to a red blood cell when it is placed in water with different placed in water with different concentrations of salt?concentrations of salt?

Results of water Results of water movement on cells – movement on cells – Osmotic PressureOsmotic Pressure

Types of Transport through plasma membrane Passive transport

– Diffusion Osmosis

– Facilitated diffusion Active transport: A transport

protein pumps a solute across a membrane in the opposite direction to the way it travels with diffusion. It requires chemical energy.

Bulk TransportBulk Transport

For larger molecules and solid For larger molecules and solid clumps of material the cell usesclumps of material the cell usesEndocytosis Endocytosis – cell takes in materials – cell takes in materials in by infoldings in the membranein by infoldings in the membrane

PhagocytosisPhagocytosis

ExocytosisExocytosis – cell releases materials – cell releases materials through membranethrough membranehttp://www.ibiblio.org/virtualcell/textbook/chapter3/cmf4a.htmhttp://www.ibiblio.org/virtualcell/textbook/chapter3/cmf4a.htmhttp://www.youtube.com/watch?v=aWItglvTiLchttp://www.youtube.com/watch?v=aWItglvTiLc

Main cell parts and Main cell parts and functionsfunctions

CytoplasmCytoplasm: holds : holds organelles - transport organelles - transport mediummedium

NucleusNucleus: Control : Control center – contains the center – contains the DNA (genetic material)DNA (genetic material)

Ribosomes: make Ribosomes: make proteinsproteins

RibosomeRibosome

RERRER: modify and : modify and transport proteinstransport proteins

SERSER: Production of : Production of lipids (fats)lipids (fats)

Golgi apparatusGolgi apparatus: Process : Process and package proteins and and package proteins and lipidslipids

ChloroplastChloroplast: Where : Where photosynthesis occurs photosynthesis occurs

MitochondriaMitochondria: Release : Release energy usable by the energy usable by the cellcell

LysosomeLysosome: Breaks : Breaks down macromolecules down macromolecules into particles the cell into particles the cell can use can use

HomeostasisHomeostasis ((homeo_homeo_=same=same

_stasis_stasis=standing still)=standing still) Unicellular organisms as well as Unicellular organisms as well as cells in multicellular organisms cells in multicellular organisms must maintain homeostasismust maintain homeostasis, or that , or that is to say, relatively constant is to say, relatively constant physical or chemical conditions.physical or chemical conditions.Unicellular organismsUnicellular organismsMulticellular organismsMulticellular organisms

To maintain HomeostasisTo maintain Homeostasis

Unicellular organismsUnicellular organisms– GrowGrow– Respond to environmentRespond to environment– reproducereproduce

Multicellular organismsMulticellular organisms– Have specialized cells that Have specialized cells that

communicate with each othercommunicate with each other

Examples of Homeostasis in humansExamples of Homeostasis in humans

ThermoregulationThermoregulation Glucose regulationGlucose regulation

Cell SpecializationCell Specialization

In multicellular organisms there is In multicellular organisms there is a division of labor among the a division of labor among the specialized cellsspecialized cells

Levels of OrganizationLevels of Organization

celltissue organ organ system

organism

Homeostatic loopsHomeostatic loops

http://www.youtube.com/watch?http://www.youtube.com/watch?v=jkioZCDHT_E&list=PL7A750281106CD067&index=38v=jkioZCDHT_E&list=PL7A750281106CD067&index=38

Examples of Homeostasis in humansExamples of Homeostasis in humans