Chapter 3 The Cellular Level of Organization. Cell Theory cells are the building blocks for...

Chapter 3

The Cellular Level of Organization

Cell Theory

•cells are the building blocks for organisms

•all cells come from pre-existing cells

•cells are the smallest unit performing all

vitalphysiological functions

•each cell maintains homeostasis

Cells

Two cells types in our body

somatic cells(Gk. body)

gametesgerm cellssex cells egg &

sperm

fig. 3-1

Cells

“model” cell

ICF

ECF

cell membrane

aka., plasma membrane

Cells

cell membrane:

physical isolationregulate exchangesensitive to environmentstructural support

functions

Cells

cell membrane:

lipidsproteinscarbohydrates

Composition

Cells

membrane lipids

phospholipid bilayer and cholesterol

hydrophilic headshydrophobic tails

barrier: ICF = ECF

ECF

ICF

Cells

phospholipid bilayer

fig. 3-2

membrane lipids

Cells

membrane proteins

Integralpart of membrane

Peripheralloosely associated

Cells

membrane protein functions:

Anchors cytoskeleton

Recognition MHC

Enzymes digestionReceptors signals

Carriers e.g. glucose

Channels water, etc.,

Cells

membrane protein functions:

fluidity of proteins

Cells

membrane carbohydrates

lubrication/protectionanchoring/locomotionreceptorsrecognition

The Cell

fig. 3-1

Cytoplasm

cytosol (ICF)with dissolved nutrients

ionsproteinswastes

organelles (little organs)

Cytoplasm

cytosol (ICF)

more K+ than ECFless Na+ than ECFmore protein than ECFstored nutrients

Cytoplasm

Organelles

non-membranous

membranous

Organelles

non-membranous

cytoskeleton

ribosomes

proteosomes

cytoskeleton strength, flexibility

microfilaments

intermediate filaments

microtubules

thick filaments

cytoskeleton

microfilaments

intermediate filaments

microtubules

thick filaments

actinanchor cytoskeleton to cytoplasm

cell shape, cell-cell attachment

hollow tubules, “motors”, spindle a.

myosin - muscle contraction

cytoskeleton

microvilli

centrioles

cilia

increase surfaceabsorption

microtubules (9 x triplets)organize spindle apparatus

microtubles (9 x doubles)+2long, slender, motile

fig. 3-3

fig. 3-4

Organelles

non-membranous

ribosomesprotein synthesissubunits (protein, rRNA)free versus fixed

cytoskeleton

Organelles

non-membranous

cytoskeleton

ribosomes

proteosomesdigest intracellular proteins

Organelles

membranous

endoplasmic reticulumGolgi apparatuslysosomesperoxisomesmitochondrianucleus

Organelles (membranous)

smooth (SER)membrane maintenancesynthesis of steroidsstorage of glycogen,glyceridesstore Ca2+ (muscle)detox of drugs (liver)

endoplasmic reticulum


rough (RER)ribosomes (fixed)protein synthesis

proteins travel viatransport vesicles to…

endoplasmic reticulum

fig. 3-5


Golgi apparatus

flattened membrane sacsmodify & package proteinsrenew cell membrane

fig. 3-1

fig. 3-6

fig. 3-7


Golgi apparatus

secretory vesiclesproducts for export

membrane renewal vesiclesmaintain membrane

lysosomesenzymes for degradationclean-up, recycle

fig. 3-8


peroxisomescarry digestive enzymes

like lysosomes, but…

different enzymesbreak down fatty acids,…protect cell from radicalsgrowth/splitting of

existing peroxisomes


mitochondria

glucose + 02 --->

double membraneproduction of energycellular respiration

H20 + CO2 + ATP


mitochondria

glucose + 02 ---> H20 + CO2 + ATP

glycolysis in cytoplasmTCA cycle in mitochondriaelectron transport “

aerobic metabolism= cellular respiration

fig. 3-9


Nucleuslargest organelle (usually)easiest to seecontrol center of cellnuclear envelopenuclear pores

fig. 3-1

Nucleus

contains:nucleolus RNA synthesischromatin (DNA)

fig. 3-10

Nucleus

contains:nucleolus RNA synthesischromatin (DNA)chromosomes (during division)

Fig 3-11

chromosome

chromatin

DNA

Nucleus

controls, directsprotein synthesis

genesDNA that “codes” for a product (protein)

fig. 3-12 transcription

fig. 3-12 translation

Nucleus

DNA mRNA protein

transcription translation

RNA polymeraserRNA, tRNAribosomes

nucleus cytoplasm

How does the nucleus “know” when to make a protein?

gene regulation ?

hormones,promoters,inhibitors,repressors,repressor inhibitors,…

Questions ?

Crossing membranes

membranes

barrier between ICF ECF

Crossing membranes

membranes

barrier between ICF ECF

permeability ability to allow things to pass

permeability ability to allow things to pass

anything passes freely permeable

nothing passes impermeable

some things pass selectivelypermeable

size,electrical charge,molecular shape,lipid solubility,…

What can cross membranes?

passiveactive

no energy requiredcell uses energy

1. Diffusion

Four types of movement

molecules moving from areas of higher concentration to areas of lower concentration

fig 3-14

higher [CO2] in ICF

lower [CO2] in ECF

even lower [CO2] in blood

1. Diffusion


DistanceMolecular sizetemperaturesize of chemical gradientelectrical “gradient”

Factors affecting diffusion

Na+ Cl-

diffusion across membranes:

pass through membrane

pass through channels

alcohol, fatty acids, steroidsdissolved gases (O2, CO2)

H2Osmall H2O soluble molecules

fig. 3-15

diffusion

proteins, glucose …

• diffusion of• water• across a selectively

permeable membrane

2. Osmosis


aside on solutions

solvent liquid used to dissolve something

solute something dissolved in a solvent

solvent + solute = solution

A. glucosewater

B. glucosewater

A vs B ?

isotonichypertonichypotonicA is (to B)

fig. 3-16

Which way will what move?

fig. 3-16

fig. 3-16

equilibrium

fig. 3-16

osmotic

pressure

Some Chemistry

atomic number

atomic weight

periodic table

Some Chemistry

atomic number

atomic weight

e.g. H = 1, C =6

e.g., H = 1, C = 12

Some Chemistry

atomic number

atomic weight

e.g. H = 1, C =6

e.g., H = 1, C = 12

daltons

Some Chemistry

1 gram of H

6.023 x 1023 atoms

= 1 mole of H

1 mole = quantity in grams that is equal to the atomic

weight

Some Chemistry

Concentration= molarity

1 mole of NaCl

Na = ~23 gCl = ~35.5 g

58.5 g/mole of NaCl

58.5 g NaCl in water

dissolve

adjust volume to 1 liter

1 mole/liter = 1 M1 molar

1 mole = 1000 mmole (millimoles)

0.9 % NaCl solution “physiological saline”

0.9 % or 0.9 g%

0.9 grams NaCl in 100 grams of H20 100 ml of H20

to board

Osmolarity = solute particles/Liter

Molarity = Moles/Liter

electrolytes = molecules that dissociate in water

Electrolytes

130 mM 10 mM

5 mM 140 mM

2-3 mM ~0 mM

110 mM 10 mM

30 mM 10 mM

Na+

K+

Ca2+

Cl-

HCO3-

ICFECF

~300 mOsm

fig. 27-2

non-elecrolytes

100 mg% 0-20mg%

200 mg% variable

150 mg% variable

6-7% 10-20%

glucose

cholesterol

triglycerides

protein

ICFECF

Osmolarity = solute particles/Liter

Molarity = Moles/Liter

electrolytes molecules that dissociate in water

NaCl dissociates

154 mMol 308 mOsm0.9 g% NaCl

fig. 3-17

RBC’s response to different solutions

ICF = 300 mOsm

300 mOsm NaCl

isosmotic

fig. 3-17


ICF = 300 mOsm

hyposmotic

.1M NaCl

100 mMol NaCl

200 mOsm NaCl

fig. 3-17


ICF = 300 mOsm

hyperosmotic

.2M NaCl

200 mMol NaCl

400 mOsm NaCl

fig. 3-17


isotonic

hypotonic

hypertonic

cell neither gains nor loses water to solution

cell swells (net gain of water) from solution

cell loses (net loss of water) to solution

3. Carrier-Mediated transport

specificity*saturationregulation

(proteins)


3. Carrier-Mediated transport


Facilitated diffusion

Active transport

fig. 3-18

specific proteinsubstrate move down gradient

facilitated diffusion

fig. 3-19

counter-transport(antiport)

againstgradient=

activetransport

++++

-----

4. Vesicular transport


Endocytosis

4. Vesicular transport


EndocytosisPhagocytosis

Exocytosis

another aside

potential differencebetween the two ends

battery

an electrical differencethat we can useto get work done

battery

+-

voltmeter

+-

voltmeter

11/2 volts

+-

voltmeter

+-

voltmeter

-0.07V-70 mV

resting potential

The Cell cycle

Interphase

Mitosis

G0

G1

S synthesis

G2

prophasemetaphaseanaphasetelophase

cytokinesis

fig. 3-23

The Cell cycle

Under genetic and environmental control

contact inhibitionattachmentgrowth factorsrepressor genestelomeres

celldivision

celldeath

celldivision

celldeath

growth

growth

fertilized egg --->adult

OK

adult ---> tumor

benign (contained)malignant (invasive)

metastasis (spread)

cancer

The Skeleton

axialappendicular

# 7# 8

axial skeleton fig. 7-1

axial skeleton fig. 7-1b

The Skeleton

appendicular

pectoral girdle + append.pelvic girdle + append.

appendicular skeleton fig. 8-1

The Skeleton

bone shape and structure

Joint Classsification (9)

Synarthrosis

Amphiarthrosis

Diarthrosis

no movement

very little movement

freely movable


Synarthrosis

Amphiarthrosis

Diarthrosis

suture parietal bonessynchondrosis epiphyseal disc

syndesmosis tibia-fibulasymphysis pubis

free movement many


Diarthrosisdiarthodial joints= synovial joints

bonearticular cartilage

“ capsulesynovial cavity

“ fluid


ligamentsACL, PCLlateral col.

menisci cart.patella


Diarthrosisdiarthodial joints= synovial joints

many different types

fig. 9-6

Chapter 3 The Cellular Level of Organization. Cell Theory cells are the building blocks for...

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