THE CELL
THE CELL
ATOMS
MOLECULES
COMPOUNDS
CELLS
ORGANELLES
THE CELL
• WHAT IS A CELL?
– ROBERT HOOKE IN MID1960’S OBSERVED CORK
WITH A COMPOUND
MICROSCOPE
– COINED THE TERM
“CELL” TO DESCRIBE
WHAT HE OBSERVED
THE CELL
• WHAT IS A CELL?
– ANTON VAN
LEEUWENHOEK
DEVELOPED NEW
MICROSCOPES AND
OBSERVED POND WATER
– OBSERVED THINGS
NEVER SEEN BEFORE!!
– DIDN’T DRAW ANY
CONCLUSIONS,
THOUGH…JUST SHARED
OBSERVATIONS
THE CELL
• WASN’T UNTIL 1800’S THAT SCIENTISTS
STARTED DRAWING
CONLCUSIONS/DEVEOPING THEORIES
THE CELL
• SCWANN AND SCHLEIDEN FIRST TO PROPOSE
THE BEGINNINGS
OF THE:
• CELL
THEORY
THE CELL
THE CELL
• THE CELL THEORY STATES THAT
– ALL LIVING THINGS ARE MADE UP OF CELLS
– CELLS ARE THE BASIC UNIT OF STRUCTURE AND
FUNCTION IN LIVING THINGS
– ALL CELLS ARISE FROM PRE-EXISTING CELLS
THE CELL
• TWO BASIC TYPES OF CELLS
– PROKARYOTES VS EUKARYOTES
• WHAT IS THE DIFFERENCE??
THE CELL
• PROKARYOTE VS
EUKARYOTE
THE CELL
• CELL SIZE
– NEED TO COME UP WITH UNITS…(μm)
THE CELL
• μm = MICROMETER
• WHAT DOES A
MICROMETER EQUAL??
• 1,000 μm = 1 mm
THE CELL
• HOW COME WE NEED
MICROMETERS?
– CELLS CAN’T BE VERY LARGE…
WHY NOT??
– IT IS DUE TO
THE SURFACE
AREA TO
VOLUME
RATIO
THE CELL
THE CELL
• CELLS MUST BE ABLE TO
OBTAIN NECESSARY
NUTRIENTS AND
REMOVE WASTES
ACROSS THEIR CELL
MEMBRANE AT A RATE
THAT SUSTAINS THEIR
NEEDS
THE CELL
• NOW THAT WE HAVE ESTABLISHED CELL SIZE,
WHAT MAKES UP THE CELL??
THE CELL
• STRUCTURES THAT
MAKE UP THE CELL ARE
CALLED??
– ORGANELLES
• ORGANELLES
–
–
–
–
–
–
–
–
–
CELL WALL
CELL MEMBRANE
NUCLEUS
ENDOPLASMIC
RETICULUM
RIBOSOMES
LYSOSOMES
MITOCHONDRIA
CHLOROPLASTS
ETC…
THE CELL
• CELL WALL
– MOST BACTERIA,
VARIOUS OTHER
MICROORGANISMS,
AND ALL PLANT
CELLS
– PROVIDES STRUCTURE
AND PROTECTION
– WHAT IS IT MADE OF?
• CELLULOSE
THE CELL
• CELL MEMBRANE (A.K.A. PLASMA
MEMBRANE)
THE CELL
• CELL MEMBRANE (A.K.A. PLASMA
MEMBRANE)
– COMPOSED OF CARBS, PROTEINS, AND LIPIDS
– PHOSPHOLIPID BILAYER
– FUNCTION?
• BARRIER BETWEEN
INTERNAL AND
EXTERNAL
ENVIRONMENTS
THE CELL
• CELL MEMBRANE (A.K.A. PLASMA
MEMBRANE)
– SELECTIVELY
PERMEABLE
• SOME SUBSTANCES
CAN PASS
THROUGH,
WHILE OTHER
SUBSTANCES
CAN NOT
THE CELL
• NUCLEUS
– MEMBRANE-BOUND
STRUCTURE THAT SERVES
AS CONTROL
CENTER FOR
METABOLISM AND
CELLULAR REPRODUCTION
– *LARGEST ORGANELLE*
– CONTAINS DNA (BLUEPRINTS)
THE CELL
• NUCLEUS
– NUCLEAR ENVELOPE
• MEMBRANE THAT
SURROUNDS
NUCLEUS
– NUCLEOLUS
• PLURAL = NUCLEOLI
• COMPOSED OF DNA/RNA/PROTEIN
• SITE OF RIBOSOMAL PRODUCTION
THE CELL
• CYTOPLASM
– WATERY MATERIAL IN THE
CELL BETWEEN THE
CELL MEMBRANE AND
NUCLEUS
– CONTAINS
DISSOLVED SUBSTANCES
THAT ARE A PART OF
METABOLIC REACTIONS
– LOCATION OF A VARIETY OF CELLULAR ORGANELLES
THE CELL
• ENDOPLASMIC
RETICULUM (E.R.)
– ROUGH E.R. VS SMOOTH
E.R.
– SYSTEM OF FLUID-FILLED
CANALS
– INVOLVED IN INTRACELLULAR TRANSPORT,
AND SURFACE AREA FOR
METABOLIC REACTIONS
WITHIN THE CELL
THE CELL
• RIBOSOMES
– COMPOSED OF
RNA AND
PROTEIN
– SOLE FUNCTION
IS PROTEIN
SYNTHESIS
THE CELL
THE CELL
• GOLGI BODY (A.K.A. GOLGI APPARATUS)
– MODIFY,
PACKAGE,
AND TRANSPORT
PROTEINS MADE
BY THE CELL
TO THEIR FINAL
DESTINATION
THE CELL
THE CELL
• LYSOSOMES
– BREAKDOWN BODY
– CONTAIN HYDROLYTIC
ENZYMES
• ENZYMES THAT
CATALYZE HYDROLYSIS
– LYSOSOMES CAN
DIGEST THE ORGANISM
IF NOT CONTAINED!!
(EX. TAY-SACHS)
– LYSOSOMAL DISEASE
THE CELL
• MITOCHONDRIA
– INVOLVED IN
CELLULAR
RESPIRATION
• ATP PRODUCTION (ATP
IS A HIGH ENERGY
MOLECULE)
– EVERY EUKARYOTIC
CELL HAS THIS
ORGANELLE!!
– WE WILL SPEND A
WHOLE CHAPTER ON
CELLULAR
RESPIRATION
THE CELL
• CYTOSKELETON
– SUPPORTS CELL,
PROVIDES
MOVEMENT
– COMPOSED OF
MICROTUBULES
AND
MICROFILAMENTS
THE CELL
• VACUOLES
– STORAGE SACKS
– DIFFERENT TYPES
• FOOD VACUOLE
• CENTRAL VACUOLE
• CONTRACTILE
VACUOLE
THE CELL
• CENTRIOLES
– INVOLVED IN CELL DIVISION
– NOT FULLY UNDERSTOOD
THE CELL
• CILIA AND FLAGELLA
– HAIRLIKE ORGANELLES INVOLVED IN CELLULAR
MOVEMENT
THE CELL
• CHLOROPLASTS
THE CELL
• CHLOROPLASTS
– INVOLVED IN PHOTOSYNTHESIS
– CONTAIN CHLOROPHYLL (SUBSTANCE THAT MAKES THEM GREEN)
– ONE OF THE
GROUP OF
ORGANELLES
CALLED
PLASTIDS
• LEUCOPLASTS
• CHROMOPLASTS
• CHLOROPLASTS
– PLASTIDS
• GROUP OF ORGANELLES
ONLY FOUND IN
PHOTOSYNTHETIC
EUKARYOTES
THE CELL
• REMEMBER, WHAT IS THE DIFFERENCE
BETWEEN PROKARYOTIC AND EUKARYOTIC
CELLS?
• WHAT ORGANELLES AREN’T IN PROKARYOTES
THAT ARE IN EUKARYOTES?
• HOW DID THOSE ORGANELLES GET THERE?
THE CELL
• ENDOSYMBIOTIC THEORY
– IT IS BELIEVED
THAT
PROKARYOTES
FUSED
TOGETHER
AND FORMED
THE FIRST
EUKARYOTIC
CELLS
THE CELL
• MAINTAINING A CONSTANT CELL
ENVIRONMENT
– THE INTERNAL ENVIRONMENT OF THE CELL MUST
BE KEPT CONSTANT AT ALL TIMES
– HOMEOSTASIS
• WHAT HAPPENS IF HOMEOSTASIS IS INTERUPTED?
– THE INTERNAL ENVIRONMENT IS CONTROLLED BY
HOMEOSTASIS, BUT WHAT ABOUT THE EXTERNAL
ENVIRONMENT?
• IT IS CONSTANTLY CHANGING!!!
THE CELL
• THE SELECTIVELY
PERMEABLE CELL
MEMBRANE PROTECTS
THE INTERNAL
ENVIRONMENT FROM
THE CRAZY CHANGES
OF THE EXTERNAL
ENVIRONMENT
THE CELL
• HOW DO SUBSTANCES THAT CAN GET
THROUGH THE MEMBRANE DO IT?
• DIFFUSION
– THE
MOVEMENT
OF PARTICLES
FROM HIGH
CONCENTRATION
TO LOW
CONCENTRATION
THE CELL
• KEY CONCEPTS WITH DIFFUSION:
– EQUILIBRIUM
– CONCENTRATION GRADIENT
• DIFFUSION IS VITAL TOWARDS THE
MOVEMENT OF PARTICLES/MOLECULES IN
AND OUT OF CELLS
THE CELL
• THE CELL
MEMBRANE CREATES
A BARRIER BETWEEN
THE INTERNAL AND
EXTERNAL
ENVIRONMENT,
LEADING TO THE
FORMATION OF A
CONCETRATION
GRADIENT WHICH
ALLOWS DIFFUSION
TO OCCUR
THE CELL
• WHAT IS THE CELL MEMBRANE MADE UP OF?
THE CELL
• SPECIALIZED
PROTEINS IN THE
CELL MEMBRANE
MAKE DIFFUSION
HAPPEN FASTER
THAN IT WOULD
NATURALLY
– FACILITATED
DIFFUSION
• DIFFUSION THAT
OCCURS WITH
ASSISTANCE (IN THIS
CASE, PROTEINS IN
THE MEMBRANE)
THE CELL
• WHO REMEMBERS WHAT THE MOST
AWESOME, COOL, RADICAL, GNARLIEST
INORGANIC COMPOUND IS??
–H2O
• BECAUSE WATER IS SO SUPER COOL, IT
HAS ITS OWN TYPE OF DIFFUSION
THE CELL
• OSMOSIS
– THE DIFFUSION OF WATER ACROSS A SELECTIVELY
PERMEABLE MEMBRANE
– WHAT CAN YOU FILL IN FOR THE WORD
DIFFUSION??
– WHY IS WATER
SO DIFFERENT?
• BECAUSE STUFF
CAN BE
DISSOLVED IN THE
WATER
THE CELL
• THE ORIGINAL “U-TUBE”
THE CELL
• OSMOSIS IS SO
POWERFUL, IT’S
“DEFYING
GRAVITY!!”
– THIS IS KNOWN
AS OSMOTIC
PRESSURE
THE CELL
• EFFECTS OF
OSMOSIS ON
CELLS
– ISOTONIC
• NO EFFECT
– HYPOTONIC
• SWELLING /
TURGID
– HYPERTONIC
• SHRIVELED /
PLASMOLYSIS
THE CELL
• DIFFUSION, FACILITATED DIFFUSION, AND
OSMOSIS ALL HAVE SOMETHING IN COMMON
– HIGH TO LOW MOVEMENT…
REQUIRING NO INPUT OF ENERGY
– MOVEMENT ACROSS A MEMBRANE WITHOUT
ENERGY INPUT IS CALLED
–PASSIVE TRANSPORT
THE CELL
• PASSIVE TRANSPORT VS ACTIVE TRANSPORT
– IF PASSIVE TRANSPORT DOESN’T REQUIRE
ENERGY…WHAT DO YOU THINK IS TRUE ABOUT
ACTIVE TRANSPORT?
– WHY DOES ACTIVE
TRANSPORT REQUIRE
ENERGY?
THE CELL
• ACTIVE TRANSPORT
– THE MOVEMENT OF MATERIALS FROM LOW
CONCENTRATION TO HIGH CONCENTRATION
THROUGH THE EXPENDITURE OF CELLULAR
ENERGY (ATP)
– TWO PROCESSES
• MOLECULE BY MOLECULE
• FORMATION OF VESICLES (VACUOLES)
– ENDOCYTOSIS & EXOCYTOSIS
THE CELL
• EXOCYTOSIS
VS.
ENDOCYTOSIS
– PINOCYTOSIS
&
PHAGOCYTOSIS
THE CELL
• WHERE DOES
THE ENERGY
FOR ACTIVE
TRANSPORT
COME FROM??
• THAT’S WHAT
CHAPTER 6 IS
ALL ABOUT!!!