A tour of the CellA tour of the Cell

Chapter 6Chapter 6http://www.youtube.com/watch?v=o1GQyciJaTA&feature=related

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

Main cell Main cell componentscomponents

Plasma membranePlasma membraneCytoplasmCytoplasmNucleusNucleusOrganellesOrganellesCell wall (only in plant cells)Cell wall (only in plant cells)

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 membraneRibosomesCell wall

NucleusEndoplasmic reticulumGolgi apparatusLysosomesVacuolesMitochondriaCytoskeleton

Compare and Contrast

Pages 112-113Pages 112-113

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

Plant cell Animal cell

Cell wallLarge vacuole

chloroplast

Centrioleslysosomes

ribosomesmitochondria

Endoplasmic reticulum

nucleus

Golgi apparatus

Plasma membrane

Plasma membraneComposed of proteins and a

type of lipid called phospholipid

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

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

passive transport (facilitated passive transport (facilitated diffusion)diffusion)

Cell energy usedCell energy used

Active transportActive transport

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 thoughdo not stop moving though

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: difusion of water through a membrane

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

Active transport

Higher Concentrationof Water

Lower Concentrationof Water

Water molecules

Sugar molecules

Water moves from high concentration to low concentration

Results of water Results of water movement on cellsmovement on cells

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.

HighConcentration

LowConcentration

CellMembrane

Glucosemolecules

Proteinchannel

Proteinchannel

Facilitated diffusion orPassive transport

Used when the cell wants to make sure it has lots of the molecule

Molecule tobe carried

LowConcentration

CellMembrane

HighConcentration

Moleculebeing carried

LowConcentration

CellMembrane

HighConcentration

Energy Energy

Molecules moved fromLOW concentration to HIGHconcentration

Energy from the cell is used

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 DNADNA

Ribosomes: make Ribosomes: make proteinsproteins

RERRER: modify and : modify and transport proteinstransport proteins

SEDSED: 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: : Releases energy Releases energy usable by the cellusable by the cell