Cell LectureCell Lecture

By Mrs. SchmitBy Mrs. Schmit

What are Cells?What are Cells?

The basic unit of life. The basic unit of life. All living things are composed of cellsAll living things are composed of cells

ProkaryotesProkaryotes

Very simpleVery simple

no “true nucleus”no “true nucleus”

Almost everything functions in the cytoplasmAlmost everything functions in the cytoplasm

Still make proteins and have DNAStill make proteins and have DNAUsually smaller more primitiveUsually smaller more primitiveOften BacteriaOften Bacteria

EukaryotesEukaryotes

have a nucleus have a nucleus

Larger, more advancedLarger, more advanced

Can be unicellular like bacteria, Can be unicellular like bacteria, protists or multicellular like animals, protists or multicellular like animals, plantsplants

The Cell TheoryThe Cell Theory

All living things are made of cells.All living things are made of cells.

Cells come from other cells (Cell Division).Cells come from other cells (Cell Division).

Cells are the smallest working units of living Cells are the smallest working units of living things. things.

What allowed us to see What allowed us to see cells?cells?

The Microscope invented by Anton Von The Microscope invented by Anton Von LeeuwenhoekLeeuwenhoek

Name cell came from Robert Hooke in Name cell came from Robert Hooke in 16651665

Levels of OrganizationLevels of Organizationcellcell

tissuetissue

organorgan

Organ systemOrgan system

OrganismOrganism

PopulationsPopulations

CommunitiesCommunities

EcosystemEcosystem

BiosphereBiosphere

Cell DiversityCell Diversity Not all cells are alike. They vary in size, shape Not all cells are alike. They vary in size, shape

and internal organization.and internal organization. Your body contains over 300 different cell typesYour body contains over 300 different cell types

Internal OrganizationInternal Organization

Cells contain a variety of internal Cells contain a variety of internal structures called organelles (organs of structures called organelles (organs of the cell).the cell).

Organelles are cell organs that perform a Organelles are cell organs that perform a specific functionspecific function

Many of these organelles contain their Many of these organelles contain their own membranesown membranes

Parts and Functions of Parts and Functions of CellCell

Cell parts are often referred to as Cell parts are often referred to as

“ “ORGANELLES”ORGANELLES”

This is the Organ of a CellThis is the Organ of a Cell

See it in the word above?See it in the word above?

CytoplasmCytoplasm

Cytoplasm

CytoplasmCytoplasm

The “juice” of the cell.The “juice” of the cell. The “right” The “right”

environment for the environment for the chemical reactions of chemical reactions of the cell.the cell.

Cell Membrane

Or phospholipid bilayerOr phospholipid bilayer

The barrier between the cell The barrier between the cell and the environment.and the environment.

Controls what gets in and Controls what gets in and out of a cell.out of a cell.

Building different Building different membranesmembranes is one way is one way different cell types are different cell types are made.made.

Plant CellPlant Cell

Cell Wall

Plant CellPlant Cell

Key Feature?

Tough, rigid

CELL WALL

Purpose is to keep organisms from penetrating the wall and getting inside the cell itself

Cell WallCell Wall

Made of cellulose.Made of cellulose. Serves to give a firm Serves to give a firm

structure to plantsstructure to plants

Can’t poop? Eat Can’t poop? Eat more fiber (cellulose)more fiber (cellulose)

Nuclear MembraneNuclear Membrane

Membrane around Membrane around nucleus. nucleus.

Carefully controls Carefully controls what gets in and out.what gets in and out.

Protects DNA!Protects DNA!

NucleusNucleus

Nucleus

NucleusNucleus

Membrane Bound*Membrane Bound* Contains DNA (the Contains DNA (the

genetic instructions genetic instructions that make you… that make you… you). you).

Endoplasmic Reticulum Endoplasmic Reticulum (ER)(ER)

ER

Endoplasmic Reticulum, Endoplasmic Reticulum, the ERthe ER

Smooth ERSmooth ER makes lipids. makes lipids. Detoxifies blood and Detoxifies blood and

poisons in liverpoisons in liver used to make used to make

membranesmembranes

Rough ERRough ER ((ribosomesribosomes)) makes proteins. makes proteins. exports proteins or movement to different exports proteins or movement to different

parts of cellparts of cell

ribosome

Golgi Body (Golgi Stack)Golgi Body (Golgi Stack)

Golgi

Golgi BodyGolgi Body Sorts proteins. Sorts proteins. Sent to:Sent to:

Secreted (released Secreted (released from cell)from cell)

Plasma MembranePlasma Membrane Membrane bound Membrane bound

organelles.organelles.

Pancreas?

Secretes INSULIN.

Not working? Diabetes.

LysosomeLysosome

Lysosome

Lysosomes and Lysosomes and peroxisomesperoxisomes

Membrane Bound*Membrane Bound* Store or destroy Store or destroy

waste.waste. Lysosomes are Lysosomes are

acidic, like your acidic, like your stomach.stomach.

VacuoleVacuole

Vacuole

VacuoleVacuole

Large in plants.Large in plants. Stores water Stores water

ChloroplastsChloroplasts

Chloroplast

ChloroplastsChloroplasts

Membrane Bound*Membrane Bound* Sunlight energy is Sunlight energy is

converted to sugar.converted to sugar. Filled with Filled with

chlorophyll, making chlorophyll, making plants GREEN!plants GREEN!

MitochondriaMitochondria

Mitochondria

MitochondriaMitochondria

Membrane Bound* Membrane Bound* (double membrane)(double membrane)

Sugar is BURNED, Sugar is BURNED, making ATP making ATP (Energy).(Energy).

PLANTS and PLANTS and ANIMALS get their ANIMALS get their ENERGY HERE!!ENERGY HERE!!

ChromosomesChromosomes

DNA, instructions for DNA, instructions for making proteinsmaking proteins

Proteins manage the Proteins manage the chemical reactions chemical reactions that are YOU!that are YOU!

Plant or Animal Cell?

RibosomesRibosomes

Make proteinsMake proteins In cytoplasm or In cytoplasm or

studding the surface studding the surface of the rough ER.of the rough ER.

Compare Plant Compare Plant and and

Animal CellsAnimal Cells

Look at your notes packet, What do you Look at your notes packet, What do you see are similar? see are similar?

What are different?What are different?

Plant Cells Animal Plant Cells Animal CellsCells

ChloroplastsChloroplasts Centrioles Centrioles

Cell WallCell Wall

Larger VacuoleLarger Vacuole

Composition of Cell Composition of Cell MembraneMembrane

Proteins

Carbohydrates

Phosphate heads

Lipid tails

Phospholipid Bilayer

or fluid mosaic modelor fluid mosaic model Called this because the membrane is fluidCalled this because the membrane is fluid two layers of phospholipids two layers of phospholipids

hydrophilic (or polar) head hydrophilic (or polar) head two long, hydrophobic (or nonpolar) tails. two long, hydrophobic (or nonpolar) tails.

This means the heads like to be near water This means the heads like to be near water (face out) while the tails prefer to be away (face out) while the tails prefer to be away from water (face towards each other) from water (face towards each other)

This can be seen when oil (nonpolar) is mixed This can be seen when oil (nonpolar) is mixed with water (polar) with water (polar)

Building different Building different membranesmembranes is one way is one way different cell types are made.different cell types are made.

Selectively PermeableSelectively Permeablehttp://http://

www.indiana.ewww.indiana.edu/~pdu/~p

hys215/hys215/lecture/lecture/lecnotes/lecnotes/lecgraphics/lecgraphics/diffusion2.gifdiffusion2.gif

http://www.ricochetprod.com/elearning/membrane/semipermeable_membrane.html

DiffusionDiffusion

Movement of molecules from a high concentration to a low concentration

When molecules spread out to an even concentration

Concentration GradientConcentration Gradient

Concentration difference on two sides of Concentration difference on two sides of a barriera barrier

High

Low

EquilibriumEquilibrium

An even concentration on both sides of An even concentration on both sides of the membranethe membrane

ExamplesExamples

PerfumePerfume GasGas Dye in waterDye in water

Ultimately the Ultimately the molecules want to molecules want to create a balance or create a balance or EQUILIBRIUMEQUILIBRIUM

Try ThisTry This

In a diffusion situation:In a diffusion situation:

OsmosisOsmosis

Movement of Movement of water from a high water from a high to a low to a low concentration, in concentration, in an attempt to even an attempt to even outout

ExamplesExamples

Soaking rice in water – little water, lots of Soaking rice in water – little water, lots of starch so water goes in.starch so water goes in.

Wants to create an EQUILIBRIUMWants to create an EQUILIBRIUM

Solve:Solve:

10 % Iodine90% H2O

100 % Water

5 % Iodine95% H2O

95 % H2O5% Iodine

PlasmolysisPlasmolysis(type of osmosis)(type of osmosis)

A special case involving osmosis and plantsA special case involving osmosis and plants When water is drawn out of the cell causing the When water is drawn out of the cell causing the

cell membrane to shrink.cell membrane to shrink.

Active and Passive Active and Passive TransportTransport

Both provide movement within or between Both provide movement within or between cellscells

Passive transport – takes NO Passive transport – takes NO energy. (like flowing energy. (like flowing downhill)downhill)

Only works from High to Low Only works from High to Low concentrations!concentrations!

Channels – only let certain things throughChannels – only let certain things through

http://bcs.whfreeman.com/thelifewire/content/chp05/0502001.html

Active transport – Active transport – Requires energy! (like Requires energy! (like walking uphill)walking uphill)

proteins- Use energy (ATP) to move proteins- Use energy (ATP) to move substancessubstances

channels – May transport two molecules channels – May transport two molecules one is being concentrated while other is one is being concentrated while other is diffusing (flowing from High to Low)diffusing (flowing from High to Low)

http://www.biologie.uni-hamburg.de/b-online/library/biolohttp://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/ATPpumA.gifgy107/bi107vc/fa99/terry/images/ATPpumA.gif

ReviewReview

Endocytosis (UPTAKE)Endocytosis (UPTAKE)

A “bubble” of membrane pinches off A “bubble” of membrane pinches off Moving large particles INTO the cell.Moving large particles INTO the cell.

Exocytosis (secretion) – Exocytosis (secretion) – think opposite of think opposite of endocytosis (like EXIT)endocytosis (like EXIT) A “bubble” of membrane fuses with the cell A “bubble” of membrane fuses with the cell

membranemembrane Large particles move OUT of the cellLarge particles move OUT of the cell..

Inside Outside

http://www.youtube.com/watch?v=4gLtk8Yc1Zc&feature=related

Diabetes:Diabetes:

Pancreas produces insulin in response to Pancreas produces insulin in response to amount of glucose (sugar) consumed by amount of glucose (sugar) consumed by the person.the person.

Activate insulin receptors to increase Activate insulin receptors to increase glucose uptake by activating the plasma glucose uptake by activating the plasma membrane glucose transporters (GLUTs)membrane glucose transporters (GLUTs)

These glucose transporters are then able to These glucose transporters are then able to channel glucose from the blood into the cell.channel glucose from the blood into the cell.

If unable to activate insulin receptor then If unable to activate insulin receptor then leads to diabetes type 2. Cells are unable leads to diabetes type 2. Cells are unable to take up glucose. to take up glucose.

Diabetes type 1 is caused by autoimmune Diabetes type 1 is caused by autoimmune destruction of the cells needed to produce destruction of the cells needed to produce the insulin in the pancreas.the insulin in the pancreas.