Cellular Transport and the Cell Cycle

Cellular Transport and the Cell Cycle

Honor Honor BiologyBiologyCh. 8Ch. 8

Honor Honor BiologyBiologyCh. 8Ch. 8

I. Cellular TransportI. Cellular Transport-- molecules constantly molecules constantly

enter and leave the enter and leave the cellcell

A. DiffusionA. Diffusion- movement of molecules

from high concentration to low conc.

- until dynamic equilibrium reached

- requires no cell energy (passive)

B.B.Osmosis:Osmosis:B.B.Osmosis:Osmosis:- diffusion of water through a

selectively permeable membrane

C. Effects of Osmosis

C. Effects of Osmosis1.1.Isotonic SolutionIsotonic Solution

- concentration of solutes the same on inside and

outside of cell

2.Hypotonic Solution2.Hypotonic Solution- solution outside of cell contains a lower conc. of solutes than the cell (more water)

a)a)Turgor pressure:Turgor pressure:a)a)Turgor pressure:Turgor pressure:- pressure inside plant cells

a)a)Turgor pressure:Turgor pressure:a)a)Turgor pressure:Turgor pressure:

Leaves and Onion Epidermis

a)a)Turgor pressure:Turgor pressure:a)a)Turgor pressure:Turgor pressure:

Plant Movements from Osmosis

b) Cytolysis:b) Cytolysis:b) Cytolysis:b) Cytolysis:- bursting of cells due to

increased osmotic pressure

c)Contractile Vacuoles:

c)Contractile Vacuoles:- “pump” water out of cells

of paramecium, ameba, etc. living in a hypotonic solution

Paramecium

3.Hypertonic Solution

3.Hypertonic Solution- solution outside of cell contains a higher conc. of solutes than the cell

(less water)

a) Plasmolysis:a) Plasmolysis:a) Plasmolysis:a) Plasmolysis:- loss of cytoplasm

(shrinking of the cell)

b) Wilting:b) Wilting:b) Wilting:b) Wilting:- loss of turgor in plant cells

D. Passive vs. Active Transport

D. Passive vs. Active Transport1.Passive Transport:

- requires no energya) Diffusion and Osmosis

b) Facilitated b) Facilitated Diffusion:Diffusion:

b) Facilitated b) Facilitated Diffusion:Diffusion:- transport proteins in

membrane move sugar, amino acids, etc.

- follows concentration gradient

b) Facilitated b) Facilitated Diffusion:Diffusion:

b) Facilitated b) Facilitated Diffusion:Diffusion:

2. Active 2. Active Transport:Transport:

2. Active 2. Active Transport:Transport:- requires cell energy

a)a) Carrier proteinsCarrier proteins transport molecules from low. conc. to high conc. using cell energy

Active Active Transport:Transport:

Active Active Transport:Transport:

b)b)Endocytosis:Endocytosis:b)b)Endocytosis:Endocytosis:

b)b)Endocytosis:Endocytosis:b)b)Endocytosis:Endocytosis:- movement of large

amounts of material into a cell by engulfing and enclosing within a membrane

- forms a vacuole within cell

b)b)Endocytosis:Endocytosis:b)b)Endocytosis:Endocytosis:

Ameba

c)c) Exocytosis:Exocytosis:c)c) Exocytosis:Exocytosis:

c)c) Exocytosis:Exocytosis:c)c) Exocytosis:Exocytosis:- expelling large amounts

of material from the cell

c)c) Exocytosis:Exocytosis:c)c) Exocytosis:Exocytosis:

ParameciumParamecium

II. Cell Size Limitations

II. Cell Size Limitations

- most cells are very small

-most cells are very small

-most cells are very small

II. Cell Size Limitations

II. Cell Size Limitations

- most cells are very small- size of most cells is

limited by several factors:

A.DNA ControlA.DNA Control- cannot make protein fast enough to support cell if cell is too large

B.B. Diffusion RateDiffusion Rate- slow and inefficient as distance increases

C.Surface Area to Volume Ratio

C.Surface Area to Volume Ratio- large cells don’t have

enough surface area (cell membrane) to support the cell with food and oxygen by diffusion

Surface Area to Volume Ratio

Surface Area to Volume Ratio

III. Cell Reproduction:

III. Cell Reproduction:- 1 cell divides into 2

identical cells- occurs millions of times

each day throughout life- each new cell requires a

full, exact copy of all chromosomes

Binary Fission in Bacteria

Binary Fission in Bacteria

DNA replicated

Membrane added

Binary Fission in Bacteria

Binary Fission in Bacteria

constriction

fission

Mitotic cell Mitotic cell divisiondivision

Mitotic cell Mitotic cell division &division &

DifferentiatiDifferentiationon

Functions of

Mitosis

Functions of

Mitosis

TissuesTissues

OrgansOrgans

FertilizeFertilized eggd egg

(zygote)(zygote)Multicell Multicell

stagestage

Asexual Reproduction by Mitosis

Asexual Reproduction by Mitosis

New IndividualsNew Individuals

Paramecium

Asexual Reproduction by Asexual Reproduction by MitosisMitosis

Asexual Reproduction by Asexual Reproduction by MitosisMitosis

Budding

Nucleus divides by mitosis

Bud forms on cell

Budding

Nucleus divides by mitosis

Bud forms on cell

Yeast

A.Chromosomes:A.Chromosomes:- made of DNA and protein- stores genetic

information (genes)- prokaryotes don’t have

chromosomes

1.Chromatin:1.Chromatin:

ChromatinChromatin

Chromosome

Chromosome

DNAdouble helix

DNAdouble helix

1.Chromatin:1.Chromatin:- active form of

chromosomes- long, thin strands of DNA

and proteinChromatin

2.Chromatid:2.Chromatid:- one of 2 replicated

halves of chromosomes

-- CentromereCentromere: : point of attachment

of 2 sister chromatids

Human Chromosomes

Human Chromosomes

B.The Cell Cycle:B.The Cell Cycle:- 3 parts

1. Interphase2. Mitosis3. Cytokinesis

overlap

The Cell Cycl

e

The Cell Cycl

etelophase

metaphase

anaphase

cell

div

isio

n

GG00: :

nondividingnondividing

interphaseinterphase

S: S: Synthesis Synthesis

of DNAof DNA

GG11: Growth: Growth

GG22: Growth: Growth

prophase

cytokinesis

Mit

osi

s

C.Interphase:C.Interphase:- period of time between cell

division- takes up 80 - 90% of a cell's life- normal cell activity and growth

NucleusNucleus

ChromatChromatinin

Nuclear Nuclear MembraMembranene

C.Interphase:C.Interphase:- period of time between cell

division- takes up 80 - 90% of a cell's life- normal cell activity and growth1. Cell growth2. DNA replication3. Synthesis of

organelles and centrioles

D. Mitosis:D. Mitosis:- 4 stages (P, M, A, T)

ProphaseProphase

MetaphaseMetaphase

AnaphaseAnaphase

TelophaseTelophase

1.Prophase1.Prophase- first and longest stagea. Chromatin condenses to form

chromosomesb. Centrioles move to

opposite ends of the cell- animal cells

only

c. Spindle fibers form- protein fibers that aid in

movement of chromosomesd. Nuclear membrane and

nucleolus disappear

2.Metaphase2.Metaphase- second and shortest stage- chromosomes line up along

the middle of the cell

3.Anaphase3.Anaphase- centromeres split

and chromosomes

move apart to opposite sides of the cell

4.Telophase4.Telophase- last stage - "reverse" of prophasea. Chromosomes revert to

chromatinb. Spindle fibers disappearc. Nuclear membrane and

nucleolus reform

E.Cytokinesis:E.Cytokinesis:1.Animal Cells

- Cell membrane pinches in forming 2

daughter cells

2. Plant Cells2. Plant Cells- Cell plate forms between 2

daughter cells

Cell plate

Which stage of mitosis?

Which stage of mitosis?

AnaphaseAnaphase

Which stage of mitosis?

Which stage of mitosis?

InterphaseInterphase

Which stage of mitosis?

Which stage of mitosis?

MetaphasMetaphasee

Which stage of mitosis?

Which stage of mitosis?

ProphaseProphase

Which stage of mitosis?

Which stage of mitosis?

TelophaseTelophase

Which stage of mitosis?

Which stage of mitosis?

ProphaseProphase

InterphaseInterphase

Which stage of mitosis?

Which stage of mitosis?

Early AnaphaseEarly Anaphase

Which stage of mitosis?

Which stage of mitosis?

MetaphaseMetaphase

Which stage of mitosis?

Which stage of mitosis?

ProphaseProphase

Which stage of mitosis?

Which stage of mitosis?

TelophaseTelophase

IV.IV. Cancer:Cancer:IV.IV. Cancer:Cancer:- disease in which cells

have lost the ability to control their own growth

Cervical Cancer Cell Dividing

A.A. Characteristics of Characteristics of Cancer Cells:Cancer Cells:

A.A. Characteristics of Characteristics of Cancer Cells:Cancer Cells:1. Rapid cell division2. Undifferentiated cells3. Metastasis:

- cells don't stick together and can move elsewhere

B.B. Causes of Cancer:Causes of Cancer:B.B. Causes of Cancer:Causes of Cancer:- genes controlling cell division have

mutated (changed)1.Carcinogens:

- cancer causing agents- nicotine, asbestos, PCB's, etc.

2.Radiation:- UV (sunlight), X-rays, radon, etc.

3.Viruses4.Hereditary factor

The The EndEnd

- in humans:- in humans:- skin cell reproduce quickly- nerve cells reproduce very slowly

Human kidney cells dividing