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D A N I L H A M M O U D I . M D
The cells
Chemical Structure of the Plasma Membrane
14. Describe the plasma membrane according to the fluid mosaic model. Include glycolipids, glycoproteins,phospholipids, cholesterol, integral proteins, and peripheral proteins.
Membrane Transport
15. Define the following terms: intracellular fluid, extracellular fluid, and interstitial fluid.
16. Define diffusion and describe how molecules diffuse across a plasma membrane. Include the following terms inyour description: passive process, simple diffusion, facilitated diffusion, carriers, and channels.
17. Define and describe osmosis. Include the following terms in your description: solvent, solute, solution, hypertonic,hypotonic, and isotonic.
18. Explain what happens to a cell placed in a hypertonic, hypotonic, or isotonic solution.
19. List and explain the five factors that affect the rate of transport of substances across cell membranes. These factorsare size of the material, temperature, the presence or absence of channels or other facilitating devices, particle charges,and the concentration gradient for the material being transported.
20. Define and describe active processes by which materials move across cell membranes.Active processes include active transport and vesicular transport. Include the following terms
in your description: ATP, pumps, exocytosis, endocytosis, phagocytosis, and receptormediated endocytosis.
Cellular Structures
21. Describe the structures and functions of the following membrane junctions: tight junctions, desmosomes,and gap junctions
Cell Theory
The cell is the basic structural and functional unit of life Organismal activity depends on individual and collective activity of cells Biochemical activities of cells are dictated by subcellular structure Continuity of life has a cellular basis
Fundamentally there are two basic types of cells
Eukaryotic cellular structure is more complex due to organellesOrganelles segregate functions, allows cell size to increase
A typical eukaryotic cell
Figure 3.2
Secretion being releasedfrom cell by exocytosis
Peroxisome
Ribosomes
Roughendoplasmicreticulum
NucleusNuclear envelopeChromatin
Golgi apparatus
Nucleolus
Smooth endoplasmicreticulum
Cytosol
Lysosome
Mitochondrion
CentriolesCentrosomematrix
Microtubule
Microvilli
Microfilament
Intermediatefilaments
Plasmamembrane
Plasma Membrane
Separates intracellular fluids from extracellular fluids Plays a dynamic role in cellular activityGlycocalyx is a glycoprotein area abutting the cell that provides highly
specific biological markers by which cells recognize oneanother, unique to each cells
• Act as an ID tag• Block cancer signal• Embryo growth• Cell protection• Immunity to infection• Cell adhesion• Fertilization
glycocalyx perturbation occurs when the circulation gets exposed to atherogenic stimuli such as oxidized lipoproteins,hyperlipidemia, and hyperglycemia.
Glycocalyx: Definition & Function - Video & Lesson Transcript | Study.com
Membranes define cellular and organelle boundaries•How does chemistry dictate function?•Why are there different lipid types?•How does material get across membranes?
Fluid Mosaic ModelDouble bilayer of lipids with imbedded, dispersed proteins Bilayer consists of phospholipids, cholesterol, and glycolipids Glycolipids are lipids with bound carbohydrate Phospholipids have hydrophobic and hydrophilic bipoles
Membrane Structure
Fluid Mosaic Model
Figure 3.3
hydrophilic means “water loving”
hydrophobic means “water repelling
Functions of Membrane Proteins
Transport
Enzymatic activity
Receptors for signaltransduction
Figure 3.4.1
Receptor Proteins
Enzymes
Transport Protein
Functions of MembraneProteins
Intercellularadhesion
Cell-cell recognition
Attachment tocytoskeleton andextracellular matrix
Figure 3.4.2
Plasma Membrane Surfaces
Differ in the kind and amount of lipids they contain
Glycolipids are found only in the outer membrane surface
20% of all membrane lipid is cholesterol
Lipid Rafts Make up 20% of the outer membrane surface
Composed of sphingolipids and cholesterol
Are concentrating platforms for cell-signaling molecules
Membrane Junctions
Tight junction – impermeable junction thatencircles the cell
Desmosome – anchoring junction scattered alongthe sides of cells
Hemidesmosomes : basalmembrane to cell
Gap junction – a nexus that allows chemicalsubstances to pass between cells
Membrane Junctions: Tight Junction
Figure 3.5a
Tight junction
Tight junctions are found in all tissues, but those ofparticular relevance to drug delivery include: Nasal tissue Gastrointestinal tissue - where oral drugs are
absorbed Blood vessels Blood-brain barrier
Tight junctions consist of proteins, for example,claudins, occludins and junctional adhesion
Membrane Junctions: Desmosome
Figure 3.5b
Membrane Junctions: Gap Junction
Figure 3.5c
A gap between adjacent cell membranescontaining very fine latticelike connectionsthat allow physiologic components to passdirectly from cell to cell. Also called nexus.
Gap Junction
Protienaceous tubes that connect adjacentcells. These tubes allow material to pass from one
cell to the next without having to passthrough the plasma membranes of the cells. Dissolved substances such as ions or glucose
can pass through the gap junctions. Large organelles such as mitochondria
connot pass. Ca++ control of gap junction opening
Passive Membrane Transport: Diffusion
II/ Facilitated diffusion
I/ Simple diffusion
Passive Membrane Transport: Diffusion
Simple diffusion – nonpolar and lipid-solublesubstances
Diffuse directly through the lipid bilayerDiffuse through channel proteins
Diffusion
Passive Membrane Transport: Diffusion
Facilitated diffusion Transport of glucose, amino acids, and ions Transported substances bind carrier proteins or pass
through protein channels
Carrier Proteins
Are integral transmembrane proteins Show specificity for certain polar molecules including
sugars and amino acids
Diffusion Through the Plasma Membrane
Figure 3.7
Extracellular fluid
Cytoplasm
Lipid-solublesolutes
Lipidbilayer
Lipid-insolublesolutes
Watermolecules
Small lipid-insolublesolutes
(a) Simple diffusiondirectly through thephospholipid bilayer
(c) Channel-mediatedfacilitated diffusionthrough a channelprotein; mostly ionsselected on basis ofsize and charge
(b) Carrier-mediated facilitateddiffusion via protein carrierspecific for one chemical; bindingof substrate causes shape changein transport protein
(d) Osmosis, diffusionthrough a specificchannel protein(aquaporin) orthrough the lipidbilayer
Passive Membrane Transport: Osmosis
Osmosis is the diffusion of water through a cellmembrane from a solution of low solute concentration toa solution with high solute concentration, up a soluteconcentration gradient.
It is a physical process in which a solvent moves, withoutinput of energy, across a semi permeable membrane(permeable to the solvent, but not the solute) separatingtwo solutions of different concentrations.
Osmosis releases energy, and can be made to dowork, as when a growing tree-root splits a stone.
Passive Membrane Transport: Osmosis
Occurs when the concentration of a solvent isdifferent on opposite sides of a membraneDiffusion of water across a semipermeable
membrane
Osmolarity – total concentration of solute particles ina solution Tonicity – how a solution affects cell volume
It has been estimated that an amount of water equivalent to roughly 250times the volume of the cell diffuses across the red blood cell membraneevery second; the cell doesn't lose or gain water because equal amountsgo in and out.
Osmotic pressure affects cell shape and life
Why this is important biologically
Kidney function is dependent upon ion and water transport
Effect of Membrane Permeability on Diffusionand Osmosis
Figure 3.8a
Effect of Membrane Permeability on Diffusion and Osmosis
Figure 3.8b
Passive Membrane Transport: Filtration
The passage of water and solutes through amembrane by hydrostatic pressure Pressure gradient pushes solute-containing fluid
from a higher-pressure area to a lower-pressure area
Effects of Solutions of Varying Tonicity
Isotonic – solutions with the same soluteconcentration as that of the cytosol
Hypertonic – solutions having greater soluteconcentration than that of the cytosol
Hypotonic – solutions having lesser soluteconcentration than that of the cytosol
Figure 3.10
Cytoplasm
Extracellular fluidK+ is released andNa+ sites are ready tobind Na+ again; thecycle repeats.
Cell ADP
Phosphorylationcauses theprotein tochange its shape.
Concentration gradientsof K+ and Na+
The shape changeexpels Na+ to theoutside, andextracellular K+ binds.
Loss of phosphaterestores the originalconformation of thepump protein.
K+ binding triggersrelease of thephosphate group.
Binding of cytoplasmicNa+ to the pump proteinstimulates phosphorylationby ATP.Na+
Na+
Na+
Na+Na+
K+K+
K+
K+
Na+
Na+
Na+
ATPP
P
Na+
Na+Na+
K+
K+
P
Pi
K+
K+
Active Transport
Uses ATP to move solutes across a membraneRequires carrier proteins
Types of Active Transport
Symport system – two substances are movedacross a membrane in the same direction
Antiport system – two substances are movedacross a membrane in opposite directions
Types of Active Transport
Primary active transport – hydrolysis of ATPphosphorylates the transport protein causingconformational change
Secondary active transport – use of anexchange pump (such as the Na+-K+ pump)indirectly to drive the transport of other solutes[ATP-ASE]
Types of Active Transport
Figure 3.11
Vesicular Transport
Transport of large particles and macromoleculesacross plasma membranes
Exocytosis – moves substance from the cell interior to theextracellular space
Endocytosis – enables large particles and macromolecules toenter the cell
Vesicular Transport
Transcytosis – moving substances into, across, andthen out of a cell
Vesicular trafficking – moving substances fromone area in the cell to another
Phagocytosis – pseudopods engulf solids and bringthem into the cell’s interior
Vesicular Transport
Fluid-phase endocytosis – the plasma membraneinfolds, bringing extracellular fluid and solutes intothe interior of the cell
Receptor-mediated endocytosis – clathrin-coated pits provide the main route forendocytosis and transcytosis
Non-clathrin-coated vesicles – caveolae that areplatforms for a variety of signaling molecules
Exocytosis
Figure 3.12a
Clathrin-Mediated Endocytosis
Figure 3.13a
Recycling ofmembrane andreceptors (if present)to plasma membrane
CytoplasmExtracellularfluid
Extracellularfluid
Plasmamembrane
Detachmentof clathrin-coatedvesicle
Clathrin-coatedvesicle
Uncoating
Uncoatedvesicle
Uncoatedvesiclefusing withendosome
To lysosomefor digestionand releaseof contents
Transcytosis
Endosome
Exocytosisof vesiclecontents
Clathrin-coatedpit
Plasmamembrane
Ingestedsubstance
Clathrinprotein
(a) Clathrin-mediated endocytosis
2
1
3
Phagocytosis
Figure 3.13b
Receptor Mediated Endocytosis
Figure 3.13c
Passive Membrane Transport – Review
Process Energy Source Example
Simple diffusion Kinetic energy Movement of O2 throughmembrane
Facilitateddiffusion Kinetic energy Movement of glucose into cells
Osmosis Kinetic energy Movement of H2O in & out ofcells
Filtration Hydrostaticpressure Formation of kidney filtrate
Active Membrane Transport – Review
Process Energy Source Example
Active transport of solutes ATP Movement of ions acrossmembranes
Exocytosis ATP Neurotransmitter secretion
Endocytosis ATP White blood cellphagocytosis
Fluid-phase endocytosis ATP Absorption by intestinal cells
Receptor-mediatedendocytosis ATP Hormone and cholesterol
uptake
Endocytosis via caveoli ATP Cholesterol regulation
Endocytosis via coatomervesicles ATP Intracellular trafficking of
molecules
Membrane Potential
Voltage across a membraneResting membrane potential – the point where K+
potential is balanced by the membrane potential Ranges from –20 to –200 mV Results from Na+ and K+ concentration gradients
across the membrane Differential permeability of the plasma membrane to Na+
and K+
Steady state – potential maintained by activetransport of ions
Generation and Maintenance of Membrane Potential
InterActive Physiology ®:Nervous System I: The Membrane Potential
Figure 3.15
Cell Adhesion Molecules (CAMs)
Anchor cells to the extracellular matrix Assist in movement of cells past one anotherRally protective white blood cells to injured or
infected areas
Roles of Membrane Receptors
Contact signaling – important in normaldevelopment and immunityElectrical signaling – voltage-regulated “ion
gates” in nerve and muscle tissueChemical signaling – neurotransmitters bind
to chemically gated channel-linked receptors innerve and muscle tissueG protein-linked receptors – ligands bind to a
receptor which activates a G protein, causing therelease of a second messenger, such as cyclic AMP
Operation of a G Protein
An extracellular ligand (first messenger), binds to aspecific plasma membrane protein The receptor activates a G protein that relays the
message to an effector protein
Operation of a G Protein
The effector is an enzyme that produces a secondmessenger inside the cell The second messenger activates a kinase The activated kinase can trigger a variety of cellular
responses
Operation of a G Protein
Figure 3.16
Extracellular fluid
Cytoplasm
Inactivesecondmessenger
Cascade of cellular responses(metabolic and structural changes)
Effector(e.g., enzyme)
Activated(phosphorylated)kinases
First messenger(ligand)
Activesecondmessenger(e.g., cyclicAMP)
Membranereceptor
G protein
1
2
3 4
5
6
Cytoplasm
Cytoplasm – material between plasma membraneand the nucleus
Cytosol – largely water with dissolved protein, salts,sugars, and other solutes
The cytosol (cf. cytoplasm, which also includes the organelles) is theinternal fluid of the cell, and where a portion of cell metabolism occurs.Proteins within the cytosol play an important role in signal transductionpathways and glycolysis. They also act as intracellular receptors and formpart of the ribosomes, enabling protein synthesis.
Cytoplasm
Cytoplasmic organelles – metabolic machinery of thecell Inclusions – chemical substances such as
glycosomes, glycogen granules, and pigment
Cytoplasmic Organelles
Specialized cellular compartmentsMembranous Mitochondria, peroxisomes, lysosomes, endoplasmic
reticulum, and Golgi apparatus
Nonmembranous Cytoskeleton, centrioles, and ribosomes
Mitochondria
Doublemembranestructure withshelf-like cristaeProvide most of
the cell’s ATP viaaerobic cellularrespirationContain their
own DNA andRNA
Mitochondria
Figure 3.17a, b
Ribosomes
Granules containing protein and rRNA Site of protein synthesis Free ribosomes synthesize soluble proteinsMembrane-bound ribosomes synthesize proteins to
be incorporated into membranes
Endoplasmic Reticulum (ER)
Interconnected tubes and parallel membranesenclosing cisternae Continuous with the nuclear membrane Two varieties – rough ER and smooth ER
Endoplasmic Reticulum (ER)
Figure 3.18a, c
Rough (ER)
External surface studded with ribosomesManufactures all secreted proteinsResponsible for the synthesis of integral membrane
proteins and phospholipids for cell membranes
Signal Mechanism of Protein Synthesis
The protein folds into a three-dimensionalconformation The protein is enclosed in a transport vesicle and
moves toward the Golgi apparatus
Signal Mechanism of Protein Synthesis
Figure 3.19
Cytosol
Ribosomes
mRNA
Coatomer-coatedtransportvesicle
Transportvesiclebudding off
Releasedglycoprotein
ERcisterna
ERmembrane
Signal-recognitionparticle(SRP)
Signalsequence
Receptorsite
Sugargroup
SignalsequenceremovedGrowing
polypeptide
1
2
34
5
Smooth ER
Tubules arranged in a looping network Catalyzes the following reactions in various organs
of the body In the liver – lipid and cholesterol metabolism, breakdown of
glycogen and, along with the kidneys, detoxification of drugs In the testes – synthesis of steroid-based hormones
Smooth ER
Catalyzes the following reactions in various organsof the body (continued) In the intestinal cells – absorption, synthesis, and transport
of fats In skeletal and cardiac muscle – storage and release of
calcium
Cytosolic Protein Degradation
Nonfunctional organelle proteins are degraded bylysosomesUbiquitin attaches to soluble proteins and they are
degraded in proteasomes
Extracellular Materials
Body fluids and cellular secretions Extracellular matrix
Developmental Aspects of Cells
All cells of the body contain the same DNA butdevelop into all the specialized cells of the body Cells in various parts of the embryo are exposed to
different chemical signals that channel them intospecific developmental pathways
Developmental Aspects of Cells
Genes of specific cells are turned on or off (i.e., bymethylation of their DNA) Cell specialization is determined by the kind of
proteins that are made in that cell
Developmental Aspects of Cells
Development of specific and distinctive features incells is called cell differentiation Cell aging Wear and tear theory attributes aging to little chemical insults
and formation of free radicals that have cumulative effectsthroughout life
Genetic theory attributes aging to cessation of mitosis that isprogrammed into our genes
Golgi Apparatus
Stacked and flattened membranous sacs Functions in modification, concentration, and
packaging of proteins Transport vessels from the ER fuse with the cis face
of the Golgi apparatus
Golgi Apparatus
Proteins then pass through the Golgi apparatus to thetrans face Secretory vesicles leave the trans face of the Golgi
stack and move to designated parts of the cell
Golgi Apparatus
Figure 3.20a
Cell trafficking Golgi is the distribution center forproteins and lipids from the ER to the vesicles andplasma membrane.Modifies N-oligosaccharides on asparagine.Adds O-oligosaccharides on serine andthreonine.Adds mannose-6-phosphate to proteins fortrafficking to lysosomes.
Endosomes are sorting centers for material fromoutside the cell or from the Golgi, sending it tolysosomes for destruction or back to themembrane/Golgi for further use.
Role of the Golgi Apparatus
Figure 3.21
Secretion by exocytosisExtracellular fluid
Plasma membrane
Vesicle incorporatedinto plasma membrane
Coatomercoat
Lysosomes containing acidhydrolase enzymes
PhagosomeProteins in cisterna
Membrane
Vesicle
Pathway 3
Pathway 2
Secretory vesicles
Proteins
Pathway 1
Golgiapparatus
CisternaRough ER
Lysosomes
Spherical membranous bags containing digestiveenzymesDigest ingested bacteria, viruses, and toxinsDegrade nonfunctional organelles Breakdown glycogen and release thyroid hormone
Lysosomes
Breakdown nonuseful tissue Breakdown bone to release Ca2+
Secretory lysosomes are found in white blood cells,immune cells, and melanocytes
I-cell disease (inclusion cell disease/mucolipidosis type II)—inherited lysosomal storagedisorder; failure of the Golgiproteins are secreted extracellularly rather than delivered to lysosomes. Results in coarsefacial features, clouded corneas, restricted joint movement, and high plasma levels oflysosomal enzymes. Often fatal in childhood.
Endomembrane System
System of organelles that function to: Produce, store, and export biological molecules Degrade potentially harmful substances
System includes: Nuclear envelope, smooth and rough ER, lysosomes, vacuoles,
transport vesicles, Golgi apparatus, and the plasmamembrane
PLAY Endomembrane System
Endomembrane System
Figure 3.23
Peroxisomes
Membranous sacs containing oxidases and catalasesDetoxify harmful or toxic substancesNeutralize dangerous free radicals Free radicals – highly reactive chemicals with unpaired electrons (i.e., O2
–) Peroxisome Membrane-enclosed organelle involved in catabolism of very-long-
chain fatty acids (through β-oxidation), branched-chain fatty acids, amino acids,and ethanol.
Barrel-shaped protein complex that degrades damaged or ubiquitin-tagged proteins.
Defects in the ubiquitin-proteasome system have been implicated insome cases of Parkinson disease.
Proteasome
Cytoskeleton
The “skeleton” of the cellDynamic, elaborate series of rods running through
the cytosol Consists of microtubules, microfilaments, and
intermediate filaments
Cytoskeleton
Figure 3.24a-b
Cytoskeleton
Figure 3.24c
Microtubules
Dynamic, hollow tubes made of the spherical proteintubulinDetermine the overall shape of the cell and
distribution of organelles
Microfilaments
Dynamic strands of the protein actin Attached to the cytoplasmic side of the plasma
membrane Braces and strengthens the cell surface Attach to CAMs and function in endocytosis and
exocytosis
Intermediate Filaments
Tough, insoluble protein fibers with high tensilestrengthResist pulling forces on the cell and help form
desmosomes
Motor Molecules
Protein complexes that function in motility Powered by ATP Attach to receptors on organelles
Motor Molecules
Figure 3.25a
Motor Molecules
Figure 3.25b
Centrioles
Small barrel-shaped organelles located in thecentrosome near the nucleus Pinwheel array of nine triplets of microtubulesOrganize mitotic spindle during mitosis Form the bases of cilia and flagella
Centrioles
Figure 3.26a, b
Cilia
Whip-like, motile cellular extensions on exposedsurfaces of certain cellsMove substances in one direction across cell surfaces
PLAY Cilia and Flagella
Cilia
Figure 3.27a
Cilia
Figure 3.27b
Cilia
Figure 3.27c
Nucleus
Contains nuclear envelope, nucleoli, chromatin, anddistinct compartments rich in specific protein setsGene-containing control center of the cell Contains the genetic library with blueprints for
nearly all cellular proteinsDictates the kinds and amounts of proteins to be
synthesized
Nucleus
Figure 3.28a
Nuclear Envelope
Selectively permeable double membrane barriercontaining pores Encloses jellylike nucleoplasm, which contains
essential solutes
Nuclear Envelope
Outer membrane is continuous with the rough ERand is studded with ribosomes Inner membrane is lined with the nuclear lamina,
which maintains the shape of the nucleus Pore complex regulates transport of large molecules
into and out of the nucleus
Nucleoli
Dark-staining spherical bodies within the nucleus Site of ribosome production
Chromatin
Threadlike strandsof DNA andhistonesArranged in
fundamental unitscalled nucleosomesForm condensed,
barlike bodies ofchromosomeswhen the nucleusstarts to divide
Figure 3.29
The double helix of DNA has these features:It contains two polynucleotide strands wound around each
other.
The backbone of each consists of alternating deoxyribose andphosphate groups.
The phosphate group bonded to the 5' carbon atom of onedeoxyribose is covalently bonded to the 3' carbon of the next.
The two strands are "antiparallel"; that is, one strand runs 5′to 3′ while the other runs 3′ to 5′.
The DNA strands are assembled in the 5′ to 3′ direction and,by convention, we "read" them the same way.
The purine or pyrimidine attached to each deoxyriboseprojects in toward the axis of the helix.
Each base forms hydrogen bonds with the one directlyopposite it, forming base pairs (also called nucleotide pairs)
In DNA, four different bases are found:•two purines, called adenine (A) and guanine (G)
•two pyrimidines, called thymine (T) and cytosine (C)
RNA contains:•The same purines, adenine (A) and guanine (G).
RNA also uses the pyrimidine cytosine (C), but instead ofthymine, it uses the pyrimidine uracil (U).
DNA Replication
DNA helices begin unwinding from the nucleosomesHelicase untwists the double helix and exposes
complementary strands The site of replication is the replication bubble Each nucleotide strand serves as a template for
building a new complementary strand
DNA Replication
The replisome uses RNA primers to begin DNAsynthesisDNA polymerase III continues from the primer and
covalently adds complementary nucleotides to thetemplate
PLAY DNA Replication
DNA Replication
Since DNA polymerase only works in one direction: A continuous leading strand is synthesized A discontinuous lagging strand is synthesized DNA ligase splices together the short segments of the
discontinuous strand
Two new telomeres are also synthesized This process is called semiconservative replication
DNA Replication
Figure 3.31
Cell Division
Essential for body growth and tissue repair
Mitosis – nuclear division
Cytokinesis – division of the cytoplasm
Mitosis
G1
E R I CN I E D E R H O F F E R
S I U - S O M
Cell Cycle
G0
6-8 hDNA, RNA,Protein
3-4 h
RNA, Protein
1 h
Mitosis, Cytokinesis
S
G2 Cyc D’sCDK4,6
Cyc B/ACDK1
Cyc ACDK2
M
Cyc ECDK2
6-12 h RNA, Protein
p53pRb
LaminH1Abl
Mitosis
The phases of mitosis are: Prophase Metaphase Anaphase Telophase
Cytokinesis
Cleavage furrow formed in late anaphase bycontractile ring Cytoplasm is pinched into two parts after mitosis
ends
Early and Late Prophase
Asters are seen as chromatin condenses intochromosomesNucleoli disappear Centriole pairs separate and the mitotic spindle is
formed
Early Prophase
Figure 3.32.2
Late Prophase
Figure 3.32.3
Metaphase
Chromosomes cluster at the middle of the cell withtheir centromeres aligned at the exact center, orequator, of the cell This arrangement of chromosomes along a plane
midway between the poles is called the metaphaseplate
Metaphase
Figure 3.32.4
Anaphase
Centromeres of the chromosomes splitMotor proteins in kinetochores pull chromosomes
toward poles
Anaphase
Figure 3.32.5
Telophase and Cytokinesis
New sets of chromosomes extend into chromatinNew nuclear membrane is formed from the rough ERNucleoli reappearGenerally cytokinesis completes cell division
Telophase andCytokinesis
Figure 3.32.6
Figure 3.30
Cell Cycle
Interphase Growth (G1),
synthesis (S),growth (G2)
Mitotic phase Mitosis and
cytokinesis
Interphase
G1 (gap 1) – metabolic activity and vigorous growthG0 – cells that permanently cease dividing S (synthetic) – DNA replicationG2 (gap 2) – preparation for division
PLAY Late Interphase
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