chapter 3 cells
DESCRIPTION
Hole's Anatomy and PhysiologyTRANSCRIPT
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Chapter 3Lecture
PowerPoint
2
2401 Anatomy and Physiology I
Chapter 3
Susan Gossett
Department of Biology
Paris Junior College
3
Hole’s Human Anatomyand Physiology
Twelfth Edition
Shier Butler Lewis
Chapter 3
Cells
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
4
3.1: Introduction
• The basic organizational structure of the human body is the cell.
• There are 50-100 trillion cells in the human body.
• Differentiation is when cells specialize.
• As a result of differentiation, cells vary in size and shape due to their unique function.
5
3.2: A Composite Cell
• Also called a ‘typical’ cell• Major parts include:
• Nucleus• Cytoplasm• Cell membrane
Microtubules
Flagellum
Nuclear envelope
Basal body
Chromatin
Ribosomes
Cell membrane
Mitochondrion
Cilia
Microtubules
Microtubule
Centrioles
Microvilli
Lysosomes
Nucleolus
Nucleus
Phospholipid bilayer
SmoothEndoplasmicreticulum
RoughEndoplasmicreticulum
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Golgiapparatus
Secretoryvesicles
6
Cell Membrane(aka Plasma Membrane)
• Outer limit of the cell• Controls what moves in and out of the cell• Selectively permeable• Phospholipid bilayer
• Water-soluble “heads” form surfaces (hydrophilic)• Water-insoluble “tails” form interior (hydrophobic)• Permeable to lipid-soluble substances
• Cholesterol stabilizes the membrane• Proteins:
• Receptors• Pores, channels and carriers• Enzymes• CAMS• Self-markers
7
Cell Membrane
Cell membraneCell membrane
(b)(a)
“Heads” ofphospholipid
“Tails” ofphospholipid
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
a: © Biophoto Associates/Photo Researchers, Inc.
Fibrous proteinCarbohydrateGlycolipidGlycoprotein
Extracellular sideof membrane
Cytoplasmic sideof membrane
Cholesterolmolecules
Globularprotein
Doublelayer ofPhospholipidmolecules
Hydrophobicfatty acid“tail”
HydrophilicPhosphate“head”
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
8
3.1 Clinical Application
Faulty Ion Channels Cause Disease
9
Cell Adhesion Molecules (CAMs)
• Guide cells on the move
• Selectin – allows white blood cells to “anchor”
• Integrin – guides white blood cells through capillary walls
• Important for growth ofembryonic tissue
• Important for growth of nerve cells
Adhesion
White blood cell
Integrin
Selectin
Exit
Splinter
Attachment(rolling)
Blood vessellining cell
Carbohydrateson capillary wall
Adhesionreceptor proteins
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
10
Cytoplasm
• Cytosol = water
• Organelles = solids
Cytoplasm is really like a Jello fruit salad where the Jello is the cytosol and the fruits (oranges, grapes, bananas, maybe walnuts,
etc.) are the organelles.
11
OrganellesEndoplasmic Reticulum (ER)
• Connected, membrane-bound sacs, canals, and vesicles• Transport system• Rough ER
• Studded with ribosomes• Smooth ER
• Lipid synthesis• Added to proteinsarriving from rough ER
• Break down of drugsRibosomes
• Free floating or connected to ER• Provide structural support and enzyme activityto amino acids to form protein
Membranes
Ribosomes
Membranes
(b) (c)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
12
Organelles
Golgi apparatus• Stack of flattened, membranous sacs• Modifies, packagesand delivers proteins
Vesicles• Membranous sacs• Store substances
Inner membrane
Outer membrane
Cristae
(a) (b)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
a: © Bill Longcore/Photo Researchers, Inc.
Mitochondria• Membranous sacs with inner partitions• Generate energy
13
Organelles
Lysosomes• Enzyme-containing sacs• Digest worn out cell parts or unwanted substances
Peroxisomes• Enzyme-containing sacs• Break down organic molecules
Centrosome• Two rod-like centrioles• Used to produce cilia and flagella• Distributes chromosomes during cell division
(a) (b)
Centriole(cross-section)
Centriole(longitudinal section)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
a: © Don W. Fawcett/Visuals Unlimited
14
Organelles
Cilia• Short hair-like projections• Propel substances on cell surface
Flagellum• Long tail-like projection• Provides motility to sperm
(a)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
a: © Oliver Meckes/Photo Researchers, Inc.
© Colin Anderson/Brand X/CORBIS
15
Microfilaments and microtubules• Thin rods and tubules• Support cytoplasm• Allows for movement of organelles
Organelles
Inclusions
• Temporary nutrients and pigments
Microtubules
Microfilaments
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
© M. Schliwa/Visuals Unlimited
16
3.2 Clinical Application
Disease at the Organelle Level
17
Cell Nucleus
•Control center of the cell
• Nuclear envelope• Porous double membrane• Separates nucleoplasm from cytoplasm
• Nucleolus• Dense collection of RNA and proteins• Site of ribosome production
• Chromatin• Fibers of DNA and proteins• Stores information for synthesis of proteins
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Nucleus
Nucleolus
Chromatin
(a)
Nuclearpores
Nuclearenvelope
18
3.3: Movements Into and Out of the Cell
Passive (Physical) Processes• Require no cellular energy and include:
• Simple diffusion• Facilitated diffusion• Osmosis• Filtration
Active (Physiological) Processes• Require cellular energy and include:
• Active transport• Endocytosis• Exocytosis• Transcytosis
19
Simple Diffusion
• Movement of substances from regions of higher concentration to regions of lower concentration• Oxygen, carbon dioxide and lipid-soluble substances
Time
Solute molecule
Water molecule
A B A B
(2) (3)
Permeablemembrane
A B
(1)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
20
Facilitated Diffusion
• Diffusion across a membrane with the help of a channel or carrier molecule• Glucose and amino acids
Region of higherconcentration
Transportedsubstance
Region of lowerconcentration
Protein carriermolecule
Cellmembrane
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
21
Osmosis• Movement of water through a selectively permeable membrane from regions of higher concentration to regions of lower concentration• Water moves toward a higher concentration of solutes
Time
Protein molecule
Water molecule
A
B
A B
(1) (2)
Selectivelypermeablemembrane
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
22
Osmosis and Osmotic Pressure
• Osmotic Pressure – ability of osmosis to generateenough pressure to move a volume of water
• Osmotic pressure increases as the concentrationof nonpermeable solutes increases
• Isotonic – same osmotic pressure• Hypertonic – higher osmotic pressure (water loss)• Hypotonic – lower osmotic pressure (water gain)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
© David M. Phillips/Visuals Unlimited
(b)
(a)
(c)
23
Filtration
• Smaller molecules are forced through porous membranes• Hydrostatic pressure important in the body• Molecules leaving blood capillaries
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Capillary wall
Larger molecules
Smaller molecules
Bloodpressure Blood
flow
Tissue fluid
24
Active Transport
• Carrier molecules transport substances across a membrane from regions of lower concentration to regions of higher concentration• Sugars, amino acids, sodium ions, potassium ions, etc.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Carrier protein Binding site
(a)
(b)
Cel
l mem
bra
ne
Carrier proteinwith altered shape
Phospholipidmolecules Transported
particle
Cellularenergy
Region of higherconcentration
Region of lowerconcentration
25
Active Transport:Sodium-Potassium Pump
• Active transport mechanism• Creates balance by “pumping” three (3) sodium (Na+) OUT and two (2) potassium (K+) INTO the cell• 3:2 ratio
26
Endocytosis• Cell engulfs a substance by forming a vesicle around the substance• Three types:
• Pinocytosis – substance is mostly water• Phagocytosis – substance is a solid• Receptor-mediated endocytosis – requires the substance to bind to a membrane-bound receptor
Nucleus Nucleolus
VesicleCellmembrane
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
27
Endocytosis
Cytoplasm
Vesicle
(a) (b) (c) (d)
Receptorprotein
Cellmembrane
Moleculesoutside cell
Cellmembraneindenting
Receptor-ligandcombination
Nucleus Nucleolus
Particle VesiclePhagocytizedparticle
Cellmembrane
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
28
Exocytosis• Reverse of endocytosis• Substances in a vesicle fuse with cell membrane• Contents released outside the cell• Release of neurotransmitters from nerve cells
Nucleus
Endoplasmicreticulum
Golgiapparatus
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
29
Transcytosis
• Endocytosis followed by exocytosis• Transports a substance rapidly through a cell• HIV crossing a cell layer
Viruses budHIV
Exocytosis
Receptor-mediated endocytosis
HIV-infectedwhite blood cells Anal or
vaginal canal
Lining of anusor vagina(epithelial cells)
Virus infectswhite blood cells onother side of lining
Receptor-mediatedendocytosis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Cellmembrane
30
3.4: The Cell Cycle
• Series of changes a cell undergoes from the time it forms until the time it divide• Stages:
• Interphase• Mitosis• Cytokinesis
Apoptosis
G2 phase
Prophase
Metaphase
AnaphaseTelophase
Cytokinesis
Restrictioncheckpoint
Remainspecialized
Proceedto division
S phase:geneticmaterialreplicates
G1 phasecell growth
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
31
Interphase
• Very active period• Cell grows• Cell maintains routine functions• Cell replicates genetic material to prepare for nuclear division• Cell synthesizes new organelles to prepare for cytoplasmic division• Phases:
• G phases – cell grows and synthesizes structures other than DNA• S phase – cell replicates DNA
32
Mitosis
• Produces two daughter cells from an original somatic cell• Nucleus divides – karyokinesis• Cytoplasm divides – cytokinesis • Phases of nuclear division:
• Prophase – chromosomes form; nuclear envelope disappears• Metaphase – chromosomes align midway between centrioles• Anaphase – chromosomes separate and move to centrioles• Telophase – chromatin forms; nuclear envelope forms
33
Mitosis
Telophase and CytokinesisNuclear envelopes begin toreassemble around two daughternuclei. Chromosomes decondense.Spindle disappears. Division ofthe cytoplasm into two cells.
AnaphaseSister chromatids separate toopposite poles of cell. Eventsbegin which lead to cytokinesis.
MetaphaseChromosomes align alongequator, or metaphase plateof cell.
ProphaseChromosomes condense andbecome visible. Nuclearenvelope and nucleolusdisperse. Spindle apparatusforms.
Late InterphaseCell has passed therestriction checkpointand completed DNAreplication, as well asreplication of centriolesand mitochondria, andsynthesis of extramembrane.
Early Interphaseof daughter cells—a time of normal cellgrowth and function.
Cleavagefurrow
Nuclearenvelopes
Nuclearenvelope
Chromatinfibers
Chromosomes
Spindle fiber
Centromere
Aster
Centrioles
Late prophase
Sisterchromatids
Microtubules
Mitosis
Cytokinesis
S phase
G1 phase
Interphase
Restrictioncheckpoint
(a)
(b)
(c)(d)
(e)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
© Ed Reschke
G2 phase
34
Cytoplasmic Division
• Also known as cytokinesis • Begins during anaphase• Continues through telophase• Contractile ring pinches cytoplasm in half
35
3.5: Control of Cell Division• Cell division capacities vary greatly among cell types
• Skin and blood cells divide often and continually• Neuron cells divide a specific number of times then cease
• Chromosome tips (telomeres) that shorten with each mitosis provide a mitotic clock
• Cells divide to provide a more favorable surface area to volume relationship
• Growth factors and hormones stimulate cell division• Hormones stimulate mitosis of smooth muscle cells in uterus• Epidermal growth factor stimulates growth of new skin
• Tumors are the consequence of a loss of cell cycle control
• Contact (density dependent) inhibition
36
Tumors
• Two types of tumors:• Benign – usually remains localized• Malignant – invasive and can metastasize; cancerous
• Two major types of genes cause cancer:
• Oncogenes – activate other genes that increase cell division• Tumor suppressor genes – normally regulate mitosis; if inactivated they are unable to regulate mitosis
• Cells are now known as “immortal”
Normal cells(with hairlike cilia)
Cancer cells
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
© Tony Brain/Photo Researchers, Inc.;
37
3.6: Stem and Progenitor Cells
• Stem cell:• Can divide to form two new stem cells
• Self-renewal• Can divide to form a stem cell and a progenitor cell• Totipotent – can give rise to every cell type• Pluripotent – can give rise to a restricted number of cell types
• Progenitor cell:• Committed cell• Can divide to become any of a restricted number of cells • Pluripotent
38
Stem and Progenitor Cells
one or more steps
Sperm
Egg
Fertilizedegg
Stem cell
Stem cell
Progenitor cell
Progenitorcell
Progenitorcell
Blood cells and platelets
Fibroblasts (a connective tissue cells)
Bone cells
Progenitorcell
Astrocyte
Neuron
Skin cell
Sebaceousgland cell
produces another stem cell(self-renewal)
Progenitorcell
Progenitorcell
Progenitorcell
Progenitorcell
Progenitorcell
Progenitorcell
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
39
3.1 From Science to Technology
Therapeutic Stem Cells
40
3.7: Cell Death
Apoptosis:
• Programmed cell death
• Acts as a protective mechanism
• Is a continuous process
41
Important Points in Chapter 3:Outcomes to be Assessed
3.1: Introduction
Define cell.
State the range of cell numbers and cells sizes in a human body.
State the term for cell specialization.
3.2: A Composite Cell
List the three major parts of a composite cell.
State the general function of organelles.
Explain how the structure of a cell membrane makes possible its function.
Describe each type of organelle, and explain its function.
Describe the parts of a cell nucleus and their functions.
42
Important Points in Chapter 3:Outcomes to be Assessed
3.3: Movement Into and Out of the Cell
Explain the various ways that substances move through the cell membrane.
Discuss how the mechanisms of crossing cell membranes differ.
3.4: The Cell Cycle
Describe the parts of the cell cycle and identify the major activities during each part.
Explain why regulation of the cell cycle is important to health.
Distinguish between mitosis and cytokinesis.
List the stages of mitosis and describe the events of each stage.
43
Important Points in Chapter 3:Outcomes to be Assessed
3.5: Control of Cell Division
Explain how different types of cells differ in their rate of cells division.
State the range of cell divisions a cell typically undergoes.
Discuss factors that influence whether or not a cell divides.
Explain how cancer arises from too-frequent cell division.
Distinguish the two types of genetic control of cancer.
3.6: Stem and Progenitor Cells
Define differentiation.
Distinguish between a stem cell and a progenitor cell.
Explain how two differentiated cell types can have the same genetic information, but different appearances and functions.
44
Important Points in Chapter 3:Outcomes to be Assessed
3.7: Cell Death
Define apoptosis.
Distinguish apoptosis from necrosis.
List the steps of apoptosis.
Describe the relationship between apoptosis and mitosis.
45
Quiz 3
Complete Quiz 3 now!
Read Chapter 4.