SAME ALIKE

STANDING STAYING

GREATER CONCENTRATION

LESSER CONCENTRATION

diffusion

TWO CRITERIA FOR OSMOSIS:

1. SUBSTANCE MUST BE WATER

2. SUBSTANCE MUST PASS THROUGH A SELECTIVELY PERMEABLE MEMBRANE

GREATER CONCENTRATION

LESSER CONCENTRATION

CONCENTRATION GRADIENT

A. solution in which the number of water molecules inside the cell is equal to the number of water molecules outside the cell

B. the number of solute molecules inside the cell is equal to the number of solute molecules outside the cell

water molecules

solute molecules

water molecules

solute molecules

C. no net movement of water or solute molecules

equal

solute molecules and water molecules constantly move into and out of the cell, but the rates of movement are equal

a cell in an isotonic solution is a cell in homeostasis!

O = water molecules X = solute molecules

X X

X

X

X

O

O

O

OO

O

X

PLANT CELL IN AN ISOTONIC SOLUTION

water entersthe cell at thesame rate as it leaves the cell

solute entersthe cell at thesame rate asit leaves the cell

normal shape and pressure

A. solution in which the number of water molecules inside the cell is less than the number of water molecules outside the cell; net movement of water is into the cell

watermolecules

greater concentrationoutside the cell

move into the cell

B. the number of solute molecules inside the cell is greater than the number of solute molecules outside the cell; net movement of solute molecules is out of the cell

solutemolecules

move out of the cell

greaterconcentrationinside the cell

C. in animal cells, it results in cytolysis (bursting of the cell due to turgor pressure – pressure that exists in a cell due to the presence of water

D. in plant cells, it results in wilted plants becoming rigid (due to gain of turgor pressure); presence of the cell wall. prevents cytolysis

cytolysis

cell membrane breaks

E. in some protists, organelles called contractile vacuoles collect water coming into the cell, then contract, and squeeze the water out of the cell through the cell membrane; prevents cytolysis

contractile vacuole

collects water coming in and contracts it out of the cell

under

PLANT CELL IN A HYPOTONIC SOLUTION

water moleculesmove into the cell

solute moleculesmove out of the cell

water molecules are smaller than solute molecules and diffuse more rapidly

plant cells swellin a hypotonic solution

X

X

X X

X

X

X

XO

O

O

O

O

O

O

O

more solute molecules inside the cell

solute move out of the cell

more water molecules outside the cell

water moves into the cell

A. solution in which the number of water molecules inside the cell is greater than the number of water molecules outside the cell; net movement of water is out of the cell

watermolecules

move out of the cell

greaterconcentrationinside the cell

B. The number of solute molecules inside the cell is less than the number of solute molecules outside the cell; net movement of solute molecules is into the cell

solutemolecules

move into the cell

greater concentrationoutside the cell

C. results in plasmolysis (shrinking of the cell due to loss of turgor pressure

above

X

X

X

X

X

XX

O

O

O

O

O OO

O

O

more solute molecules outside the cell

solute moves into the cell

more water molecules inside the cell

water moves out of the cell

PLANT CELL IN A HYPERTONIC SOLUTION

water moleculesmove out of the cell

solute moleculesmove into of the cell

plant cell loses turgor pressure and shrinks

plasmolysis occurs plant wilts

the movement of particlesacross the plasma membrane without the expenditure of energy

Examples of passive transport:

1. diffusion

2. osmosis

3. facilitated diffusion

greater concentration

lesser concentration

transport protein

greaterconcentration

lesserconcentration

carrierprotein

energy

the movement of materials across a membrane against the concentration gradient and requiring the expenditure of chemical energy

1. channel proteins – form channels that allow specific molecules to flow through; movement is with the concentration gradient and requires no energy input from the cell

channel protein

2. carrier proteins – proteins that change the shape to allow a substance to pass through the plasma membrane; movement is with the concentration gradient and requires no energy input from the cell

carrier protein

endocytosis

within

process of endocytosis in which fluid materials are engulfed into the cell; forms a vacuole

process of endocytosis in which large particles are engulfed into the cell; forms a vacuole

to drink

to eat

exocytosis

out

DIFFUSION RATES

NUTRIENTS OXYGEN

CARBON DIOXIDE

CELL’S DNA

most cells are uninucleated – contain only one nucleus tomanage all of the cell’s processes

DNA deoxyribonucleic acid “master molecule of the cell”

SURFACE AREA -TO - VOLUME RATIO

1 mm 2 mm 4 mm

surface area = width x width x 6 sides

26 mm

224 mm

296 mm

volume = width x width x width

31 mm

38 mm

364 mm

1 mm 2 mm 4 mm

6: 1 3 : 1 1.5 : 1

best surface area-to-volume ratio

6 / 1 24 / 8 96 / 64

CELL DIVISION MITOSIS

CHROMOSOMES

GENES

COLORED

BODY

HOMOLOGOUS CHROMOSOMES

THE SAME

FORM

1. chromatids each of the two identical halves of a chromosome; sometimes called “sister chromatids”

2. centromerethe point of attachmentof the sister chromatids

center

portion share

3. upper arm the part of a chromosomelocated above the centromereknown as the “p” arm (petite)

4. lower armthe part of the chromosomelocated below the centromere;known as the “q” arm

upper arm is always the smallestarm if the centromere is not in the center

5. allelesgenes for the same traitthat may have differingexpressions and locatedat the same location on sister chromatids

shape of nosestraight, pug, roman

hair colorred, blonde, black, brown

genetic diseasenormal, diseased

DNA

nucleosomehistone

continued coilingwithin supercoil

supercoil withinchromosomechromosome

METACENTRIC

ACROCENTRIC

SUBMETACENTRIC

PROTEINS

HEREDITARY UNITS

BORN

FIRST

GENE

CHROMATIN

CHROMOSOMES

RNA

REPLICATION

COLORED

HISTONE

HISTONEPROTEINS

CHROMATINTHREADS

KARYOTYPE

22 pairs or 44

1 pair or 2

X and X sex chromosomes = female

X and Y sex chromosomes = male

23 pairs or 46

PARENT CELL

REPLICATION

DAUGHTER CELL

PARENT CELL

DAUGHTER CELL

continuous sequence of growth and division of a cell, which is controlled by key enzymes

1. period of growth

2. period of division

A. mitosis = division of the nucleus

B. cytokinesis = division of the cytoplasm

1. the busiest phase of the cell cycle

2. G phase (gap 1 phase) – rapid growth and metabolic activity 1

G phase 1

interphase

G = growth

3. S phase (synthesis phase) – DNA synthesis and replication

S phase

S =synthesis

G phase 2

G phase (gap 2 phase) – centrioles replicate; cell prepares 2 for division

(.AVI)

1. first and longest phase of mitosis

first

2. chromatin coils and becomes visible as chromosomes

chromosomes

each chromosome consists of two sister chromatids

3. the nuclear envelope and nucleolus disintegrate

disappearing nuclear envelope

nucleolus disintegrated

4. centrioles in animal cells start migrating toward opposite poles

centrioles

5. in animal cells, the spindle begins to form

spindle fibers

spindle fibers are microtubules that form from centriole to centriole

1. the second and shortest phase of mitosis

middle

2. the doubled chromosomes become attached to the spindle fibers by their centromeres

each sister chromatid is attached to its own spindle fiber

spindle fibers

centromere

sister chromatids

3. the chromosomes are pulled by the spindle fibers and begin to line up on the midline, or equator, of the spindle

equator

one sisterchromatidis attached to the spindle fiber at one pole

the other sister chromatidis attached to the spindle fiber at the other pole

1. the third phase of mitosis in which the separation of sister chromatids occurs

up

2. the centromeres split apart and the chromatid pairs separate from each other

the chromatids are pulled apart by the shortening of the microtubules in the spindle fibers

chromatids

1. the fourth and final phase of mitosis

end

2. chromatids reach opposite poles of the cell

pole of the cell

pole of the cell

chromatids chromatids

3. chromosomes unwind and elongate into chromatin

6. the spindle fibers break down and disappear

4. the nuclear envelope reforms around the chromatin

5. the nucleolus reappears

7. cytokinesis occurs

8. two daughter cells are formed

division of the cytoplasm

twoidenticaldaughter cells

interphase

prophase

anaphase

telophase

metaphase

interphase

prophase

metaphase

anaphase

telophase

1. animal cells – cytokinesis begins during early anaphase when the plasma membrane begins pinching in from the outside to the inside to form the cleavage furrow until the cell divides into two identical daughter cells

2. plant cells – vesicles formed by the Golgi apparatus fuse at the equator of the cell forming the cell plate which grows from the inside to the outside until the cell divides into two identical daughter cells; the cell plate forms into the cell wall

1. division of the nucleus

kernel nucleus

motion

2. division of the cytoplasm

cell

1. guarantees the continuity of life, resulting in the production of two new cells with chromosome sets that are identical to those of the parent cell

2. unicellular organisms remain as single cells – produces two complete new organisms

3. multicellular organisms result in cell growth and reproduction which provides new tissues, organs, and organ systems

1. set of proteins that control the cell cycle

2. proteins that attach to the cyclin and become activated

a malignant growth resulting from uncontrolled cell division

Possible causes of cancer:

1. genetic factors – predisposition in the family; genes inherited

2. environmental factors – smoking; air and water pollution

3. viral infections – that damage the genes

HEALTHY LIFESTYLE!!!

1. no cigarette smoking

2. low fat diet

3. high fiber in diet