cellular transport and the cell cycle honor biology ch. 8
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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