Chapter 8 NotesChapter 8 Notes

Cellular Transportation And The Cellular Transportation And The Cell CycleCell Cycle

Cell TransportationCell Transportation: : 2 main types2 main types

1.1. Passive transportPassive transport: : Does notDoes not require require energy from the cellenergy from the cell

Moves downhill, Moves downhill, withwith the concentration the concentration gradientgradient

Cellular Transportation Cellular Transportation Type 2Type 2

22. . Active TransportActive Transport: : Requires energyRequires energy to to

occur.occur.

Moves uphill, Moves uphill, againstagainst the concentration the concentration gradient.gradient.

Passive TransportPassive Transport(No energy required)(No energy required)

3-Types3-Types

11stst Type Passive Transport Type Passive Transport

Simple DiffusionSimple Diffusion : Movement of any : Movement of any substance from areas of substance from areas of higher to lowerhigher to lower concentrationsconcentrations

diffusion animationdiffusion animation

22ndnd Type Passive Transport Type Passive Transport

Osmosis:Osmosis: Movement of Movement of waterwater from from areas of areas of higher to lowerhigher to lower concentrations concentrations

33rdrd Type Passive Transport Type Passive Transport

Facilitated diffusionFacilitated diffusion: Movement of : Movement of substances from substances from higher to lowerhigher to lower concentration with help from a protein concentration with help from a protein moleculemolecule

Animation: How Facilitated Diffusion WorksAnimation: How Facilitated Diffusion Works

2-Types of Active Transport2-Types of Active Transport (Energy Required)(Energy Required)

11. . ExocytosisExocytosis: The expulsion of particles : The expulsion of particles from the cell.from the cell.

2. 2. EndocytosisEndocytosis: surrounding and engulfing : surrounding and engulfing particles.particles.

PinocytosisPinocytosis: Cell drinking – the cell : Cell drinking – the cell takes in liquids.takes in liquids.

PhagocytosisPhagocytosis: Surrounding and : Surrounding and taking in of large particles.taking in of large particles.

PhagocytosisPhagocytosis

Animation: Animation: PhagocytosisPhagocytosis

Solute vs SolventSolute vs Solvent

SoluteSolute: The dissolved substance in a : The dissolved substance in a liquid.liquid.

SolventSolvent: The liquid that the solute is : The liquid that the solute is dissolved in: Usually waterdissolved in: Usually water

Types of solutionsTypes of solutionsIsotonic solutionIsotonic solution

Concentrations of Concentrations of solute are equal in the solute are equal in the cell and the solution. cell and the solution. (cell=solution)(cell=solution)

Water moves back Water moves back and forth at the same and forth at the same rate. rate.

Water in =Water OutWater in =Water Out

Hyp-O-tonic solutionHyp-O-tonic solution(Hyp-Ohh no I’m swelling-tonic)(Hyp-Ohh no I’m swelling-tonic)

HypHypOOtonictonic: Concentrations of solute are : Concentrations of solute are higher in the cell than in the solution (cell-higher in the cell than in the solution (cell-higher, solution-lower) higher, solution-lower)

Water moves into the cell.Water moves into the cell.The cell The cell swellsswells and can burst. and can burst.

Hypertonic SolutionHypertonic Solution

Concentrations of Concentrations of solute are lower in the solute are lower in the cell than in the cell than in the solution (cell-lower, solution (cell-lower, solution-higher) solution-higher)

Water moves out of Water moves out of the cellthe cell..

The cell The cell shrinksshrinks..

Limits to cell sizeLimits to cell size

A cells size is limited, so organisms grow A cells size is limited, so organisms grow by cellular division.by cellular division.

The cells of a baby are the same size as The cells of a baby are the same size as the cells of an adult.the cells of an adult.

So… Why Can’t cells just grow So… Why Can’t cells just grow larger???larger???

Three factors that limit the growth Three factors that limit the growth of cellsof cells

1. Diffusion across cell surface.1. Diffusion across cell surface.2. Shortage of DNA.2. Shortage of DNA.3. Surface to volume ratio.3. Surface to volume ratio.

DiffusionDiffusion

Diffusion is efficient over short distances, Diffusion is efficient over short distances, but becomes inefficient and slow over but becomes inefficient and slow over large distances.large distances.

So…cells that are large have a more So…cells that are large have a more difficult time getting nutrients into the cell difficult time getting nutrients into the cell and waste products out of the cell.and waste products out of the cell.

DNADNA

A cell cannot survive without sufficient A cell cannot survive without sufficient amounts of DNA to make necessary amounts of DNA to make necessary proteinsproteins

Unusually large cells must have multiple Unusually large cells must have multiple nuclei in order to supply needed DNAnuclei in order to supply needed DNA

Surface Area to Volume RatioSurface Area to Volume Ratio

As a cell’s size increases, its volume increases As a cell’s size increases, its volume increases faster than its surface areafaster than its surface area

Cell ReproductionCell Reproduction

MitosisMitosis: Asexual reproduction (Cell Cycle): Asexual reproduction (Cell Cycle)

The process by which one cell divides into The process by which one cell divides into two cells, both identical to the original two cells, both identical to the original parent cellparent cell

The Dreaded “The Dreaded “CC” Words!” Words!

ChromatinChromatinChromosomesChromosomesChromatidChromatidCentromeresCentromeresCentiolesCentioles

ChromatinChromatin

Relaxed DNA.Relaxed DNA.

ChromosomesChromosomes

Condensed DNA.Condensed DNA.

DNA that is preparing DNA that is preparing to undergo cellular to undergo cellular divisiondivision

Can now be seen with Can now be seen with a microscope.a microscope.

Chromatids and CentromeresChromatids and Centromeres

Sister Chromatids: Halves of a duplicated Sister Chromatids: Halves of a duplicated parent chromosome.parent chromosome.

Centromeres: The structure that joins two Centromeres: The structure that joins two sister chromatids.sister chromatids.

Chromatin and ChromosomeChromatin and Chromosome

Centrioles- Produce the spindle Centrioles- Produce the spindle and aid in replicationand aid in replication

The Cell CycleThe Cell Cycle

The process of The process of asexuaasexual reproduction l reproduction (mitosis) of the cell(mitosis) of the cell

Contains Contains threethree major parts major parts

1. Interphase 2. Mitosis 3. Cytokinesis1. Interphase 2. Mitosis 3. Cytokinesis

The Cell CycleThe Cell Cycle

Part One of the Cell CyclePart One of the Cell CycleInterphaseInterphase

The cell spends the majority of its life in The cell spends the majority of its life in interphase.interphase.

A time in which the cell is preparing for A time in which the cell is preparing for division.division.

Chromosomes appear as threadlike coils Chromosomes appear as threadlike coils (chromatin)(chromatin)

InterphaseInterphase3-Parts3-Parts

G-1G-1: Maturation.: Maturation.

S-PhaseS-Phase: DNA replicates - makes a : DNA replicates - makes a duplicate copy of itself. (# doubles)duplicate copy of itself. (# doubles)

G-2G-2: Organelles replicate and final : Organelles replicate and final preparations for division.preparations for division.

MitosisMitosis

Division of the Division of the nucleusnucleus4-phases4-phases

PProphaserophaseMMetaphaseetaphaseAAnaphasenaphaseTTelophaseelophase

PMATPMAT

Parts of MitosisParts of MitosisProphaseProphase

The chromatin The chromatin condense to form condense to form visible chromosomesvisible chromosomes

The nuclear envelope The nuclear envelope begins to dissolvebegins to dissolve

The centrioles divide The centrioles divide and and beginbegin to move to to move to opposite sides of the opposite sides of the cellcell

Parts of Mitosis Cont…Parts of Mitosis Cont…MetaphaseMetaphase

Centrioles have moved Centrioles have moved to opposite sides of the to opposite sides of the cellcell

The spindle has formedThe spindle has formed

Chromosomes are Chromosomes are lined up in the middle lined up in the middle of the cell across the of the cell across the equatorequator

Parts of Mitosis Cont…Parts of Mitosis Cont…AnaphaseAnaphase

The centromeres split The centromeres split and the spindles pull and the spindles pull the sister chromatids the sister chromatids apart toward opposite apart toward opposite sides of the cellsides of the cell

Parts of Mitosis Cont…Parts of Mitosis Cont…TelophaseTelophase

The chromosomes The chromosomes move to opposite move to opposite sides of the cell. sides of the cell.

The nuclear envelope The nuclear envelope begins to reform begins to reform around each set of around each set of chromosomes at chromosomes at opposite sides of the opposite sides of the cell.cell.

CytokinesisCytokinesis

Division of the Division of the cytoplasmcytoplasm

Begins to occur Begins to occur during telophaseduring telophase

Different in plants and Different in plants and animal cellsanimal cells

Cytokinesis Cont…Cytokinesis Cont…

Animal cellsAnimal cells: the plasma membrane : the plasma membrane pinches in to form two separate cellspinches in to form two separate cells

Plant cellsPlant cells: A rigid cell plate begins to form : A rigid cell plate begins to form between the two new cells, dividing them between the two new cells, dividing them and becoming a cell wall.and becoming a cell wall.

Mitosis animationMitosis animation

Control of the Cell CycleControl of the Cell Cycle

The cell cycle is controlled by proteins and The cell cycle is controlled by proteins and enzymesenzymes

Contact with other cells causes cell to stop Contact with other cells causes cell to stop dividing. dividing.

Cell stop dividing when they lose contact Cell stop dividing when they lose contact with other cellswith other cells

CancerCancer

Uncontrolled cell growth resulting in Uncontrolled cell growth resulting in tumorstumors

Metastasis:Metastasis: Cells break lose and travel Cells break lose and travel through the circulatory system spreading through the circulatory system spreading throughout the body.throughout the body.

Causes of CancerCauses of Cancer

Environmental factors that damage genes.Environmental factors that damage genes.

Ex: Cigarette smoke, UV rays from the sun, Ex: Cigarette smoke, UV rays from the sun, air and water pollution, virusesair and water pollution, viruses