Cells!Cells! Chapter 7Chapter 7

What is a cell?What is a cell?A cell is the basic unit A cell is the basic unit of life.of life.– The smallest living The smallest living

thing.thing.

– All living things are All living things are made of cellsmade of cells

How did we find cells?How did we find cells?

1600s began to use 1600s began to use microscopes to observe microscopes to observe living thingsliving things– Robert Hooke Robert Hooke (1665)(1665)

Came up with the phrase Came up with the phrase ‘cell’‘cell’

Built a microscope that Built a microscope that allowed him to look at very allowed him to look at very tiny objectstiny objects

Sliced a very thin piece of Sliced a very thin piece of cork and looked at it cork and looked at it through his microscopethrough his microscope

A fabric merchantA fabric merchant

Looked at pond scum.Looked at pond scum.

First to discover First to discover unicellular organismsunicellular organisms..– He named them He named them

“animacules” or “little “animacules” or “little animals”.animals”.

Anton van LeeuwenhoekAnton van Leeuwenhoek(1674)(1674)

Schleiden and SchwannSchleiden and Schwann

Matthias SchleidenMatthias Schleiden (1838) (1838)– A German scientist who A German scientist who

studied cells.studied cells.– Concluded that all plants are Concluded that all plants are

made of cellsmade of cells

Theodor SchwannTheodor Schwann (1839) (1839)

**Concluded that all animals Concluded that all animals are made of cellsare made of cells

Rudolph Virchow 1855Rudolph Virchow 1855German doctorGerman doctor

Discovered that cells could not developDiscovered that cells could not develop

from anything but other cellsfrom anything but other cells

- This idea completed the cell theory- This idea completed the cell theory

Cell TheoryCell Theory

All living things are All living things are composed of cellscomposed of cells

Cells are the basic Cells are the basic units of structure and units of structure and function in living function in living thingsthings

New cells come from New cells come from existing cellsexisting cells

Chapter 7 VocabularyChapter 7 VocabularyPages 169-193Pages 169-193

Please add the following Please add the following 15 words to your 15 words to your notes!notes!

CellCell

Cell TheoryCell Theory

EukaryoteEukaryote

ProkaryoteProkaryote

OrganelleOrganelle

Cell SpecializationCell Specialization

TissueTissue

Organ Organ 

Organ SystemOrgan System

Diffusion Diffusion 

OsmosisOsmosis

EquilibriumEquilibrium

IsotonicIsotonic

HypertonicHypertonic

HypotonicHypotonic

Diversity of Cellular LifeDiversity of Cellular Life

Unicellular OrganismsUnicellular Organisms– Made of a single cellMade of a single cell– Majority of life on Majority of life on

EarthEarth

Multi-cellular Multi-cellular OrganismsOrganisms– Made of many cellsMade of many cells– Depend on specialized Depend on specialized

cellscells

Plant v. Animal CellsPlant v. Animal Cells

Read through the articles about plant and animal Read through the articles about plant and animal cells.cells.– From the reading From the reading list 5 differenceslist 5 differences between a plant and between a plant and

animal cell.animal cell.

On the plant cell color:On the plant cell color:– Nucleolus, nucleus, chloroplast, vacuole, Rough ER, Nucleolus, nucleus, chloroplast, vacuole, Rough ER,

smooth ER, cell wall, cytoplasmsmooth ER, cell wall, cytoplasm

On the animal cell color:On the animal cell color:– Microfilaments, lysosome, ribosome, chromatin, Microfilaments, lysosome, ribosome, chromatin,

centrioles, microtubules, mitochondria, nuclear pores, centrioles, microtubules, mitochondria, nuclear pores, nuclear envelope, cell membrane, golgi complexnuclear envelope, cell membrane, golgi complex

Organelle FlashcardsOrganelle FlashcardsAt your desk you will find all the materials At your desk you will find all the materials you need to set up your flashcards.you need to set up your flashcards.

1.1. Please cut outPlease cut out::11 Animal cells11 Animal cells8 Plant cells8 Plant cells

2.2. Glue the cut out cells onto one side of a Glue the cut out cells onto one side of a flashcard. You should have 19 totalflashcard. You should have 19 total

3.3. We will fill out the cards together as a class We will fill out the cards together as a class when everyone has them put together.when everyone has them put together.

OrganellesOrganelles

Specialized structure that performs Specialized structure that performs important functions in the important functions in the eukaryoticeukaryotic cell cell

Golgi Apparatus (Complex)Golgi Apparatus (Complex)– Products of the endoplasmic reticulum are Products of the endoplasmic reticulum are

modified, stored or sent to other destinations modified, stored or sent to other destinations outside of celloutside of cell

– Found in plant and animal cellsFound in plant and animal cells

Cell MembraneCell Membrane– Allows passage of oxygen, nutrients, and Allows passage of oxygen, nutrients, and

wastes in and out of the cellwastes in and out of the cell– Provides protection and supportProvides protection and support– Found in plant and animal cellsFound in plant and animal cells

CytoplasmCytoplasm– Portion of the cell outside the nucleusPortion of the cell outside the nucleus– Helps to maintain cellular shapeHelps to maintain cellular shape– Found in plant and animal cellsFound in plant and animal cells

Nuclear Envelope (membrane)Nuclear Envelope (membrane)– Surrounds nucleus, separates from cytoplasm– Allows material to move in and out of the nucleus– Provides support and protection for the nucleus– Found in plant and animal cells

Nuclear PoreNuclear Pore– Holes which allow material to move into or out of Holes which allow material to move into or out of

the nucleusthe nucleus– Found in plant and animal cellsFound in plant and animal cells

Cell WallCell Wall– Protects the plant cell, maintains its shape, prevents Protects the plant cell, maintains its shape, prevents

excessive water intakeexcessive water intake– Found only in plant cellsFound only in plant cells

Endoplasmic ReticulumEndoplasmic Reticulum– Where lipids are assembled; proteins and Where lipids are assembled; proteins and

other materials released from cellother materials released from cell– SmoothSmooth: lacks ribosomes; synthesizes lipids, : lacks ribosomes; synthesizes lipids,

metabolizes carbohydrates, detoxificationmetabolizes carbohydrates, detoxification– RoughRough: ribosomes attached to surface; : ribosomes attached to surface;

responsible for protein production; modifies responsible for protein production; modifies proteinsproteins

Found near nucleusFound near nucleus

– Found in plant and animal cellsFound in plant and animal cells

MitochondriaMitochondria– Site of cellular respiration (generates energy)Site of cellular respiration (generates energy)

Convert chemical energy in food to a form cells Convert chemical energy in food to a form cells can usecan use

– Found in plant and animal cellsFound in plant and animal cells

NucleusNucleus– Contains all genes (genetic information), Contains all genes (genetic information),

chromatin, chromosomes and nucleoluschromatin, chromosomes and nucleolus– Controls protein synthesisControls protein synthesis– Found in plant and animal cellsFound in plant and animal cells

ChloroplastChloroplast– Site of photosynthesis, convert solar energy Site of photosynthesis, convert solar energy

to chemical energyto chemical energy– Found only in plant cellsFound only in plant cells

LysosomeLysosome– Digest macromolecules (lipids, proteins, Digest macromolecules (lipids, proteins,

carbohydrates)carbohydrates)– Found only in animal cellsFound only in animal cells

RibosomeRibosome– Where proteins are madeWhere proteins are made– Found in plant and animal cellsFound in plant and animal cells

VacuoleVacuole– Stores materials (water, salts, proteins, Stores materials (water, salts, proteins,

carbohydrates)carbohydrates)– Large size in plants (support)Large size in plants (support)– Plant cells and some animal cellsPlant cells and some animal cells

NucleolusNucleolus– Inside nucleusInside nucleus– Synthesizes components of ribosomesSynthesizes components of ribosomes

Found in plant and animal cellsFound in plant and animal cells

ChromatinChromatin– In nucleusIn nucleus– Made of DNA + Protein which gives us Made of DNA + Protein which gives us

chromosomes.chromosomes.– Contain instructions for traits & characteristics Contain instructions for traits & characteristics – Found in plant and animal cellsFound in plant and animal cells

CentrioleCentriole– Help cell division –only 2 in cellHelp cell division –only 2 in cell– Only found in animal cells.Only found in animal cells.

CytoskeletonCytoskeleton– MicrotubuleMicrotubule

maintain cell shape and help form the maintain cell shape and help form the spindle in cell divisionspindle in cell division

– MicrofilamentMicrofilamentaid in movement and supportaid in movement and support

Levels of OrganizationLevels of Organization

Individual CellsIndividual CellsTissuesTissues– Cells grouped togetherCells grouped together– A group of similar cells that perform a particular A group of similar cells that perform a particular

functionfunction

OrgansOrgans– Tissues work togetherTissues work together

Organ SystemsOrgan Systems– Group of organs that work together to perform a Group of organs that work together to perform a

specific functionspecific function

Cell specializationCell specialization: cells develop in : cells develop in different ways to perform different tasksdifferent ways to perform different tasks– Animal cellsAnimal cells: red blood cells (transport : red blood cells (transport

oxygen), pancreas (protein production), oxygen), pancreas (protein production), muscle cells (movement)muscle cells (movement)

– Plant cellsPlant cells: guard cells (regulate exchange in : guard cells (regulate exchange in leaves)leaves)

Cell BoundariesCell Boundaries

Cell MembraneCell Membrane– Thin flexible barrier that surrounds a cellThin flexible barrier that surrounds a cell– Regulates what enters and leaves the cell, Regulates what enters and leaves the cell,

provides protection and supportprovides protection and support

Cell WallCell Wall– Strong supporting layer around the cell Strong supporting layer around the cell

membranemembrane

Cell MembraneCell Membrane

Made of two layers Made of two layers (lipid bilayer)(lipid bilayer)– Gives cell membranes Gives cell membranes

a flexible structure that a flexible structure that forms a strong barrierforms a strong barrier

Contains protein and Contains protein and carbohydrate carbohydrate moleculesmolecules– Helps materials cross Helps materials cross

the membranethe membrane

Cell WallCell Wall

Found outside the cell membrane (plants)Found outside the cell membrane (plants)– Main function to provide support and Main function to provide support and

protectionprotection

Allows water, oxygen, carbon dioxide to Allows water, oxygen, carbon dioxide to pass throughpass through

Made from carbohydrates and proteinMade from carbohydrates and protein

DiffusionDiffusion

Movement of dissolved molecules from Movement of dissolved molecules from one side of cell membrane to anotherone side of cell membrane to another

Particles move from an area where they Particles move from an area where they are more concentrated to an area where are more concentrated to an area where they are less concentratedthey are less concentrated

Substances diffuse across a membrane Substances diffuse across a membrane without the cell using any energywithout the cell using any energy

Facilitated DiffusionFacilitated Diffusion

Cell membrane has Cell membrane has certain channels that certain channels that make it easy for make it easy for certain molecules to certain molecules to cross the membranecross the membrane– Will only occur if there Will only occur if there

is a higher is a higher concentration on one concentration on one side of the membraneside of the membrane

Active TransportActive Transport

Small molecules and ions are carried across Small molecules and ions are carried across membranes by proteinsmembranes by proteins– Requires energy, cells use majority of their energy for Requires energy, cells use majority of their energy for

transporttransport

EndocytosisEndocytosis– Process of taking material into the cell by folding of Process of taking material into the cell by folding of

cell membranecell membrane

ExocytosisExocytosis– Membrane of vacuole fuses with cell membrane Membrane of vacuole fuses with cell membrane

forcing contents out of cellforcing contents out of cell

OsmosisOsmosis

Diffusion of waterDiffusion of water across a selectively across a selectively permeable membranepermeable membrane

– Most membranes selectively permeableMost membranes selectively permeable some substances can pass through and others some substances can pass through and others cannotcannot

Water passes easily across most membranesWater passes easily across most membranes

OsmosisOsmosis

How Osmosis works…How Osmosis works…– Water will move across the membrane until Water will move across the membrane until

equilibrium is reachedequilibrium is reachedMoves from high to low concentrationMoves from high to low concentration

– Osmotic pressureOsmotic pressure: pressure on the hypertonic : pressure on the hypertonic side of a selectively permeable membraneside of a selectively permeable membrane

SolutionsSolutions

HypertonicHypertonic: side of the membrane with : side of the membrane with more molecules; “above strength”more molecules; “above strength”

HypotonicHypotonic: the side of the membrane with : the side of the membrane with less molecules; “below strength”less molecules; “below strength”

IsotonicIsotonic: concentrations the same on both : concentrations the same on both sides of the membrane; “same strength”sides of the membrane; “same strength”

Osmosis LabOsmosis Lab

Tomorrow we will be completing a lab in Tomorrow we will be completing a lab in class that illustrates the process of class that illustrates the process of osmosis.osmosis.Today you shouldToday you should……– Read through entire lab procedureRead through entire lab procedure– Complete all pre-lab questionsComplete all pre-lab questions– Write a hypothesisWrite a hypothesis– Identify manipulated, responding and control Identify manipulated, responding and control

variables.variables.