CELLS

THE CELL THEORY

THE TENETS OF THE CELL THEORY

• ALL ORGANISMS ARE COMPOSED OF ONE OR MORE CELLS

• THE CELL IS THE STRUCTURAL UNIT OF LIFE

• CELLS CAN ARISE ONLY BY DIVISION FROM A PREEXISTING CELL.

CELLS

EUKARYOTIC VS PROKARYOTIC

CHARACTERISTICS

• SIMILAR CHARACTERISTICS DUE TO COMMON ANCESTORS

• DIFFERING CHARACTERISTICS DUE TO EVOLUTION

SIMILARITIES

• CELL MEMBRANES

• GENETIC INFORMATION

• TRANSCRIPTION AND TRANSLATION

• METABOLIC PATHWAYS

• ENERGY CONSERVATION

• PHOTOSYNTHESIS

• SIMILAR ENZYMES

DIFFERENCES

• COMPLEXITY OF CHROMOSOMES

• DIVISION OF CELLS– MEIOSIS/MITOSIS

• LIPID MEMBRANE BOUND ORGANELLES

• MITOCHONDRIA/CHLOROPLASTS

• CYTOSKELETON

• CILIA• ENDOCYTOSIS &

EXOCYTOSIS• CELLULOSE/CHITIN IN

CELL WALLS• DIPLOIDY• RNA POLYMERASES• SEXUAL

REPRODUCTION

KARYON = NUCLEUS

• PRO = BEFORE • EU = TRUE

                             

 

CYTOPLASM

PROKARYOTIC ORGANELLES

• NON MEMBRANE BOUND ORGANELLES

• NUCLEOID• PLASMIDS• RIBOSOMES• INCLUSION BODIES

– SOME

• MEMBRANE BOUND ORGANELLES

• PLASMA MEMBRANE– LIPID

– MESOSOMES

• INCLUSION BODIES– SOME

EUKARYOTIC ORGANELLES• BOUND BY LIPID

MEMBRANES• MITOCHONDRIA• CHLOROPLASTS• LYSOSOMES• ENDOPLASMIC

RETICULUM• GOLGI APPARATUS• PLASMA MEMBRANE• NUCLEUS• MICROBODIES• VACUOLES/VESSICLES

• NOT BOUND BY LIPID MEMBRANES

• RIBOSOMES• CENTRIOLES• BASAL BODIES• CYTOSKELETON

CELL DIVISION

• EUKARYOTE• DIVISION OF THE

NUCLEUS– MITOSIS– MEIOSIS

• DIVISION OF THE CYTOPLASM– CYTOKINESIS– BINARY FISSION– BUDDING

• PROKARYOTE• NO NUCLEUS• BINARY FISSION• BUDDING

MITOSIS/BINARY FISSION

                                                                               

MITOSIS/BUDDING

MITOSIS/CYTOKINESIS

PROKARYOTIC BINARY FISSION

• http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_2.html

PROKARYOTIC BUDDING

SEXUAL RECOMBINATION

• EUKARYOTES– MEIOSIS

• PROKARYOTES– TRANSDUCTION

– TRANSFORMATION

– CONJUGATION

CELL STRUCTURE AND FUNCTION

EUKARYOTIC VS PROKARYOTIC

THE PROKARYOTES

KINGDOM MONERA

GENERALIZED STRUCTURE

CELLULAR APPENDAGES

• COMMON BUT NOT FOUND ON ALL SPECIES

• FLAGELLA AND AXIAL FILAMENTS

• FIMBRIAE AND PILI

ATTACHMENTS FOR MOTILITY

FLAGELLA

• EXTREMELY THIN• PROVIDES

MOTILITY• FILAMENT• HOOK• BASAL BODY• ROTATES 360

DEGREES

FLAGELLAR ARRANGEMENTS

MONOTRICHOUS,

LOPHOTICHOUS,

AMPHITRICHOUS,

PERITRICHOUS

MONOTRICHOUS

LOPHOTRICHOUS

AMPHITRICHOUS

PERITRICHOUS

SWIMMING SPEED OF BACTERIA

• POLAR FLAGELLATED--THIOSPIRILLUM, PSEUDOMONAS AERUGINOSA

• PERITRICHOUS--ESCHERICIA COLI

BACTERIAL FLAGELLA AND TAXONOMY

• NUMBER AND PLACEMENT CAN HELP IDENTIFY SPECIES

• SPECIAL STAINS OR ELECTRON MICROSCOPE

• MOTILITY MEDIUM

• HANGING DROP SLIDE

CHEMOTAXIS

• RESPOND TO CHEMICAL SIGNALS

• POSITIVE TOWARD

• NEGATIVE AWAY

• DETECTION OF CHEMICALS IS LINKED TO FLAGELLA

• CELL IS DRIVEN CLOCKWISE IN RUNS AND TUMBLES

CHEMOTAXIS

INTERNAL FLAGELLA

• SPIROCHETES

• AXIAL FILAMENTS

• MODIFIED FLAGELLUM

• ENCLOSED IN PERIPLASMIC SPACE

• ENDOFLAGELLUM

• GIVE TWISTING OR FLEXING MOTION

APPENDAGES FOR ATTACHMENT AND MATING

FIMBRIAE

• SMALL BRISTLE FIBERS

• COMPOSITION VARIES

• STICKY

• ALLOW ADHESION OF PATHOGENS

• ESCHERICIA COLI, & NEISSERIA GONORRHEAE

PILI

• SEX PILUS

• ELONGATED, RIGID, TUBULAR

• PILIN

• GRAM NEGATIVE BACTERIA

• CONJUGATION

• PRODUCTION IS CONTROLLED GENETICALLY

THE CELL ENVELOPE

EVERYTHING OUTSIDE PROTOPLASM

THE GLYCOCALYX

• PROTECTS CELL FROM SEVERE ENVIRONMENTS

• DIFFERS GREATLY IN COMPOSITION, THICKNESS, AND ORGANIZATION

• SLIME LAYER• CAPSULE• NOT ABSOLUTELY ESSENTIAL TO

SURVIVAL

CAPSULES

• STREPTOCOCCUS PNEUMONIAE

• HAEMOPHILUS INFLUENZAE

• BACILLUS ANTHRACIS

• USUALLY MORE PATHOGENIC

• AVOID PHAGOCYTES

VARIATION IN THE GLYCOCALYX

• PLAQUE ON TEETH• COLONIZERS OF

PLASTIC, METAL

CELL WALL• IMMEDIATELY BELOW

GLYCOCALYX• DETERMINES SHAPE OF

CELL• PREVENTS BURSTING AND

COLLAPSE• MOST HAVE

PEPTIDOGLYCAN• PENICILLIN,

CEPHALOSPORIN, LYSOZYME, ALCOHOL AND DETERGENTS TARGET

GRAM STAINING

• DIVIDES INTO TWO MAJOR GROUPS

• GRAM NEGATIVE • GRAM POSITIVE

GRAM POSITIVE STAIN

IMPORTANCE OF DIFFERENCES

• GRAM NEGATIVE MORE IMPERVIOUS TO SOME ANTIMICROBIAL CHEMICALS

• GRAM NEGATIVE HARDER TO KILL• ALCOHOL IS EXCEPTION• REQUIRES DIFFERENT TREATMENT

OF GRAM NEGATIVE AND GRAM POSITIVE DISEASES

CELL MEMBRANE

• BELOW CELL WALL

• LIPID BILAYER • PROTEINS

EMBEDDED• 30-40%

PHOSPHOLIPIDS• 60-70% PROTEINS

MESOSOMES

• MESOSOMES-EXTENSIONS INTO CYTOPLASM

• PROMINENT IN GRAM +

• INCREASE SURFACE AREA

• MAY BE ARTIFACTS

• MAY HAVE ROLE IN DIVISION AND WALL SYNTHESIS

MESOSOME FUNCTION

• ENERGY REACTIONS

• NUTRIENT PROCESSING & SYNTHESIS

• REGULATE TRANSPORT

• SECRETION

INTERNAL STRUCTURES

CHROMATIN BODIES

• SINGLE STRAND OF DNA

• NUCLEOID REGION• NO HISTONES• HAPLOID

PLASMIDS

• NOT ESSENTIAL

• EXTRACHROMOSOMAL

• CAN BE FREE OR INCORPORATED INTO CHROMOSOME

• CONFER PROTECTIVE TRAITS

• DRUG RESISTANCE

• TOXIN & ENZYME PRODUCTION

RIBOSOMES

• IN CYTOPLASM• POLYSOMES • ATTACHED TO

MESOSOMES AND MEMBRANE

• 60% rRNA & 40% PROTEIN

RIBOSOMES

• 30s & 50 s SUBUNITS

• CLASSIFIED BY SVEDBERG UNITS

INCLUSION BODIES

• VARY IN SIZE, NUMBER & CONTENT

• PROTEIN LAYER MEMBRANE

• GLYCOGEN

• POLYBETAHYDROXYBUTRYRATE

• GAS VACUOLES

POLYHYDROXYBUTYRATE

GRANULES

• SULFUR GRANULES

• POLYHYDROXYBUTRATE GRANULES

• PHOSPHATE GRANULES

• METACHROMATIC GRANULES

SULFUR GRANULES

POLYPHOSPHATE GRANULES

GAS VACUOLES

ENDOSPORES

• BACILLUS, CLOSTRIDIUM & SPOROSARCINA

• VEGETATIVE CELL & ENDOSPORE

• VALUABLE IN CLASSIFYING BACTERIA

ENDOSPORE GERMINATION

• REVITALIZE WHEN FAVORABLE CONDITIONS REAPPEAR

• BREAK DORMANCY• NEEDS WATER, SPECIFIC CHEMICAL,

ENVIRONMENTAL STIMULUS• OCCURS RAPIDLY• ENZYMES FROM SPORE DIGEST CORTEX • REVERTS TO VEGETATIVE CELL

BACTERIAL SHAPES

• ROUND--COCCUS

• ROD--BACILLUS• SPIRAL--

SPIRILLUM

PLEOMORPHISM

• VARIATIONS IN SHAPE

• INDIVIDUAL VARIATIONS IN CELL WALLS

• CAUSED BY NUTRITIONAL OR GENETIC DIFFERENCES

EUKARYOTES CELLS

EUKARYOTIC CELLS

• ABOUT 2 BILLION YEARS AGO

• EVOLVED FROM PROKARYOTIC SYMBIONTS

• SINGLE CELLED

• INDEPENDENT

• SOME FORMED COLONIES AND FILAMENTS

FORM AND STRUCTURE

CYTOPLASM

• EVERYTHING BETWEEN CELL MEMBRANE AND NUCLEAR MEMBRANE

• ORGANELLES

• CYTOSOL

NUCLEOPLASM

• MATERIAL IN NUCLEUS

ENDOPLASMIC RETICULUM

• PARALLEL • FLAT • THIN POUCHES• ROUGH E.R.• SMOOTH E.R.

SMOOTH ER

• RESPONSIBLE FOR LIPID METABOLISM

• SITE OF COMPLEX CARBOHYDRATE ANABOLISM

• DETOXIFICATION

ROUGH E.R.• ORIGINATES FROM OUTER

PART OF NUCLEAR ENVELOPE

• CONTINUOUS LABYRINTH

• MAY REACH CELL MEMBRANE

• STUDDED WITH RIBOSOMES

• MAKES PROTEINS FOR EXPORT

RIBOSOMES

• FREE • BOUND• POLYRIBOSOMES

POLYRIBOSOMES

RIBOSOMAL STRUCTURE

• 60s RIBOSOME• 40s RIBOSOME• PRODUCED IN

NUCLEOLUS

80 s RIBOSOME SUBUNIT

40 s RIBOSOME SUBUNIT

GOLGI COMPLEX

• SAC LIKE • TO ONE SIDE OF

NUCLEUS • CISTERNAE• SIMILAR TO E.R.• MODIFIES,

PACKAGES, SHIPS

LYSOSOMES

• SAC OF HYDROLYTIC ENZYMES

• INTRACELLULAR DIGESTION OF FOOD PARTICLES

• PROTECTION AGAINST INVADERS

• REMOVAL OF DEBRIS

MICROBODIES

• CONTAIN OXIDATIVE ENZYMES

• PROMOTE MANY METABOLIC REACTIONS

• PEROXISOMES ONE EXAMPLE

MITOCHONDRIA

• ENERGY SUPPLIER• VARIOUS SHAPES• SMOOTH

CONTINUOUS OUTER MEMBRANE

• INNER FOLDED MEMBRANE

• CRISTAE

CRISTAE

• SITE OF ELECTRON TRANSPORT SYSTEM

MATRIX

• SITE OF ENZYMES OF TCA CYCLE

INTERMEMBRANOUS SPACE

• SITE OF PREPRATORY REACTION– FORMATION OF

ACETYL CoA FROM PYRUVATE

• SITE OF BETA OXIDATION– CONVERSION OF

FATTY ACIDS TO ACETYL CoA

OUTER MITOCHONDRIAL MEMBRANE

• PERMEABLE TO PYRUVATE

• NOT TO NADH

MITOCHONDRIAL GENETICS

• OWN DNA• OWN RIBOSOMES

(70s)• POOL OF ENZYMES • INDEPENDENT

DIVISION

PLASTIDS

CHLOROPLASTS, LEUKOPLASTS, AND

CHROMOPLASTS

CHLOROPLASTS

• ALGAE • PLANTS• CONVERT

SUNLIGHT TO CHEMICAL ENERGY

• PRODUCE OXYGEN

• CHLORPHYLL• CAROTENOIDS

• CHLAMYDOMONAS • PLANT CELL

LEUKOPLASTS

• STORAGE OF STARCH OR OTHER MATERIALS

CHROMOPLASTS

• CONTAIN PIGMENTS

CYTOSKELETON

• ANCHORING ORGANELLES

• PROVIDING SUPPORT

• PERMITS SHAPE CHANGES

MICROTUBULES• LONG HOLLOW

TUBULES

• MAINTAIN SHAPE OF CELLS WITHOUT WALLS

• TRANSPORT SUBSTANCES IN CELL

• SPINDLE FIBERS

• FLAGELLA & CILIA

MICROFILAMENTS

• THIN PROTEIN STRANDS

• FORM NETWORK• MOVEMENT OF

CYTPOLASM• AMEBOID

MOVEMENT

INTERMEDIATE FILAMENTS

CENTRIOLES, CILIA AND FLAGELLA

CENTRIOLES

• ASSOCIATED WITH NUCLEAR DIVISION

• FOUND IN CENTROSOME

• HOLLOW ROD OF NINE SETS OF MICTOTUBULES

CILIA & FLAGELLA

• MOTILITY• PROTOZOA• MANY ALGAE• SOME FUNGAL

PROTISTS• SOME ANIMAL

CELLS

FLAGELLA • THICKER• LONG SHEATHED

CYLINDER• MICROTUBULES• 9 +2 ARRANGEMENT• SLIDE OVER ONE

ANOTHER• WHIPLIKE MOVEMENT• REQUIRES ENERGY• CELL MEMBRANE

COORDINATES

BASAL BODIES

• FOUND AT BASE OF CILIA AND FLAGELLA

• SIMILAR STRUCTURE TO CENTRIOLE

CILIA

• SHORTER• MORE NUMEROUS• CILATES &

ANIMAL CELLS• MOTILITY,

FEEDING & FILTERING

• 2, 500 MICRONS PER SECOND

VESICLES &VACUOLES

• STORAGE• FATS• GLYCOGEN• CONTRACTILE

VACUOLES CONTROL OSMOTIC PRESSURE

NUCLEUS

• LARGEST ORGANELLE

• SURROUNDED BY NUCLEAR ENVELOPE

• PORES• NULEOPLASM• CHROMATIN• NUCLEOLUS

NUCLEOLUS

• DEVELOPS AROUND THE NUCLEAR ORGANIZER

• SYNTHESIS OF RIBOSOMAL RNA

• USUALLY DISAPPEARS DURING CELL DIVISION

• MAY BE MORE THAN ONE IN NUCLEUS

GENETIC MATERIAL

• CHROMATIN• CHROMATID• CHROMOSOMES

CHROMATIN

• IRREGULAR NETWORK OF STRANDS

• HISTONE PROTEIN AND UNCOILED DNA

• TRANSCRIPTION OR DUPLICATION MAY BE OCCURRING

EUCHROMATIN VS HETEROCHROMATIN

CHROMATIDS

CHROMOSOMES

CHROMOSOMAL NUMBER

• SPECIFC # OF CHROMOSOMES

• 2 SETS OF EACH--DIPLOID

• 1 SET OF EACH --HAPLOID

• MITOSIS• MEIOSIS

IMPORTANCE OF THE NUCLEUS

• NUCLEUS GOVERNS CELL ACTIVITIES

• DOES THROUGH RIBOSOMES, ROUGH ENDOPLASMIC RETICULUM

GLYCOCALYX• OUTER MOST BOUNDARY

• POLYSACCHARIDES

• NETWORK OF FIBERS

• SLIME LAYER

• CAPSULE

• PROTECTION

• ADHERANCE

• SIGNALRECEPTION

• VARY GREATLY

CELL WALL

• RIGID

• STRUCTURAL SUPPORT

• THICK INNER LAYER OF POLYSACCHARIDE FIBERS

• CHITIN OR CELLULOSE

• THIN OUTER LAYER OF GLYCANS

• PECTINS, MANNANS, MINERALS

PLASMODESMATA

COMPONENTS OF THE CELL WALL

• CHITIN OR CELLULOSE

• PECTINS, MANNANS AND MINERALS

CELLULOSE

• LONG POLYSACCHARIDE CHAIN

• ACTS LIKE REBAR IN CONCRETE

• LIGNIN MAY BE PRESENT TO HELP REINFORCE

CHITIN

• POLYSACCHARIDE• FOUND IN FUNGAL

CELL WALLS• FOUND IN

EXOSKELETON OF INSECTS

CHITIN

PROTISTS

• SOME FUNGAL PROTISTS HAVE A MIXTURE OF CHITIN AND CELLULOSE

• SOME PROTISTS HAVE A PELLICLE– CELL WALL LIKE

STRUCTURE

PELLICLE

ANIMALS DO NOT HAVE CELL WALLS

• TUNICATES DO HAVE A CELLULOSE SKELETON BUT IT IS NOT A CELL WALL

CYTOPLASMIC MEMBRANE

• TYPICAL BILAYER• STEROLS• CONFER

STABILITY• SELECTIVELY

PERMEABLE• 60 - 80 % OF CELL

VOLUME IS ORGANELLES

JUNCTIONAL COMPLEXES

• TIGHT JUNCTIONS

• DESMOSOMES

• HEMIDESMOSOMES

• GAP JUNCTIONS

• PLASMODESMATA

TIGHT JUNCTIONS

• FUSION OF OUTERMOST PORTION OF MEMBRANE

• BRAIN• DIGESTIVE TRACT• TESTES

DESMOSOMES

• MEMBRANE CLOSE TOGETHER

• PLAQUES IN BOTH CELLS

HEMIDESMOSOMES

• CELLS CLOSE TOGETHER

• PLAQUE ONLY IN ONE CELL

PLASMODESMATA

GAP JUNCTIONS

• SEPARATE CELLS BUT CLOSE TOGETHER

• CHANNELS BETWEEN CELLS

                

                    

COMPARISON OF EUKARYOTIC CELLS

PLANT, ANIMAL, AND FUNGAL CELLS

PLANT CELL ANIMAL CELL

• CELL WALL• PLASTIDS• VACUOLES• NO CENTRIOLES

• NO CELL WALL• NO PLASTIDS• VESSICLES• CENTRIOLES