the cell. you must know… the differences between prokaryotic and eukaryotic cells the structure...
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THE CELL
YOU MUST KNOW…• THE DIFFERENCES BETWEEN
PROKARYOTIC AND EUKARYOTIC CELLS
• THE STRUCTURE AND FUNCTION OF ORGANELLES COMMON TO PLANT AND ANIMAL CELLS
• THE STRUCTURE AND FUNCTION OF ORGANELLES FOUND ONLY IN PLANT CELLS OR ONLY IN ANIMAL CELLS
CONCEPT 6.2• EUKARYOTIC CELLS HAVE
INTERNAL MEMBRANES THAT COMPARTMENTALIZE THEIR FUNCTIONS
CHARACTERISTICS PROKARYOTICCELLS
EUKARYOTICCELLS
PLASMA MEMBRANE YES YES
CYTOSOL WITHORGANELLES
YES YES
RIBOSOMES YES YES
NUCLEUS NO YES
SIZE 1 UM-10UM 10 UM-100UM
INTERNAL MEMBRANE NO YES
CELLS• PROKARYOTIC CELLS CONTAIN
DOMAINS BACTERIA AND ARCHAEA
• EUKARYOTIC CELLS CONTAIN DOMAINS PROTISTS, FUNGI, PLANTS, ANIMALS
PROKARYOTES• CHROMOSOMES ARE GROUPS
TOGETHER IN A REGION CALLED THE NUCLEOID
• NO MEMBRANE-BOUND ORGANELLES ARE FOUND IN THE CYTOSOL
EUKARYOTES• A MEMBRANE-ENCLOSED
NUCLEUS CONTAINS THE CHROMOSOMES
• MANY MEMBRANE-BOUNDED ORGANELLES
IN THE
CYTOPLASM
PLASMA MEMBRANE• FORMS THE BOUNDARY FOR A CELL• SELECTIVELY PERMEABLE AND
PERMITS THE PASSAGE OF MATERIALS INTO AND OUT OF THE CELL
• MADE OF PHOSPHOLIPIDS, PROTEINS, AND ASSOCIATED CARBOHYDRATES
NUCLEUS• CONTAINS MOST OF THE CELL’S DNA• DNA SERVES AS A TEMPLATE TO
MAKE mRNA• CONTROL CENTER OF THE CELL• SURROUNDED BY THE NUCLEAR
MEMBRANE, A DOUBLE MEMBRANE• NUCLEAR ENVELOPE IS
COUNTINUOUS WITH THE ROUGH E.R.
NUCLEUS• CONTAINS NUCLEAR PORES THAT
CONTROL WHAT ENTERS OR LEAVES THE NUCLEUS
• CHROMATIN IS THE COMPLEX OF DNA• NUCLEOLUS IS THE REGION WHERE rRNA
COMPLEXES WITH PROTEINS TO FORM RIBOSOMAL SUBUNITS
RIBOSOMES• SITES OF PROTEIN SYNTHESIS • CONSIST OF A LARGE AND SMALL
SUBUNIT AND MAY BE FREE FLOATING IN THE CYTOSOL (FOR MAKING PROTEINS FOR USE WITHIN THE CELL) OR ATTACHED TO ROUGH E.R. (WHEN MAKING PROTEINS FOR EXPORT OR USE IN THE CELL MEMBRANES)
E.R.• NETWORK OF MEMBRANES AND
SACS WHOSE INTERNAL AREA IS CALLED THE CISTERNAL SPACE
• 2 TYPES – SMOOTH AND ROUGH E.R.
SMOOTH E.R.• 3 FUNCTIONS• SYNTHESIS OF LIPIDS• METABOLISM OF
CARBOHYDRATES• DETOXIFICATION OF
DRUGS AND POISONS
ROUGH E.R.• THE PROTEINS MADE IN THE
RIBOSOMES ON THE ROUGH E.R. TRAVEL ACROSS THE E.R. MEMBRANE AND IN TO THE CISTERNAL SPACE
• PROTEINS ARE CONCENTRATED MORE BEFORE THEY ARE MOVED BY TRANSPORT VESICLE TO THE GOLGI APPARATUS FOR ADDITIONAL MODIFICATION
GOLGI APPARATUS• PROTEINS ARE MODIFIED,
STORED, AND SHIPPED• HAVE POLARITY – THE CIS FACE
RECEIVES VESICLES, THE TRANS FACE SHIPS VESICLES
MITOCHONDRIA• SITE OF CELLULAR RESPIRATION • ATP IS CREATED • ENCLOSED BY A DOUBLE
MEMBRANE, THE
INNER MEMBRANE
HAS INFOLDS
CALLED CRISTAE
PEROXISOMES• SINGLE MEMBRANE BOUND
COMPARTMENTS • RESPONSIBLE FOR VARIOUS
METABOLIC FUNCTIONS THAT INVOLVE THE TRANSFER OF HYDROGEN FROM COMPOUNDS TO OXYGEN, PRODUCING H2O2
• BREAK DOWN F.A. TO BE SENT TO THE MITOCHONDRIA FOR FUEL AND DETOXIFY ALCOHOL BY TRANSFERRING HYDROGEN FROM THE POISON TO OXYGEN
CYTOSKELETON• NETWORK OF PROTEIN FIBERS• RESPONSIBLE FOR SUPPORT,
MOTILITY, AND REGULATING SOME BIOCHEMICAL ACTIVITIES
• 3 TYPES – MICROTUBULES, MICROFILAMENTS, INTERMEDIATE FILAMENTS
MICROTUBULES• LARGEST OF THE FIBERS• SHAPE AND SUPPORT THE CELL • TRACKS FOR ORGANELLES TO
MOVE• SEPARATE CHROMOSOMES
DURING MITOSIS AND MEIOSIS• STRUCTURAL COMPONENTS OF
CILIA AND FLAGELLA
MICROFILAMENTS• MADE OF THE PROTEIN ACTIN• WHEN COUPLED WITH MYOSIN, IT
CAUSES MOVEMENT• EX. AMEBOID MOVEMENT,
MUSCLE
CONTRACTION
INTERMEDIATE FILAMENTS
• MORE PERMANENT FIXTURES IN THE CELL
• HELP MAINTAIN SHAPE OF THE CELL
• VARY DEPENDING
ON LOCATION
AND FUNCTION
CENTROSOMES• REGION NEAR THE NUCLEUS
WHERE MICROTUBULES GROW• CONTAIN CENTRIOLES IN ANIMAL
CELLS
CELL STRUCTURES ASSOCIATED WITH
ANIMAL CELLS ONLY
LYSOSOMES• SACS OF HYDROLYTIC ENZYMES
THAT CAN DIGEST LARGE MOLECULES INCLUDING PROTEIN, POLYSACCHARIDES, FATS, AND NUCLEIC ACIDS
• BREAK DOWN MACROMOLECULES TO ORGANIC MONOMERS THAT ARE RELEASED IN THE CYTOSOL AND RECYCLED BY THE CELL
• WORK BEST IN ACIDIC ENVIRONMENT
CENTRIOLES• LOCATED WITHIN THE
CENTROSOME WHERE THEY REPLICATE BEFORE CELL DIVISION
SPECIALIZED MICROTUBULES
• FLAGELLA - COMMON IN UNICELLULAR EUKARYOTIC ORGANISMS
• CILIA – SHORTER AND MORE NUMBEROUS, CAN BE USED IN LOCOMOTION OR MOVE OVER THE SURFACE OF THE TISSUE
COMMON ULTRASTRUCTURE
• CONTAIN 9 PAIRS OF MICROTUBULES SURROUNDING A CENTRAL CORE OF 2 MICROTUBULES
• ARRANGEMENT IS REFERRED TO AS THE
“9+2 PATTERN”
EXTRACELLULAR MATRIX
• SITUATED JUST EXTERNAL TO PLASMA MEMBRANE
• COMPOSED OF GLYCOPROTEINS SECRETED BY THE CELL (COLLAGEN)
• STRENGTHENS TISSUES • SERVES AS A CONDUIT FOR
TRANSMITTING EXTERNAL STIMULI INTO THE CELL, TURNING ON GENES, MODIFYING BIOCHEMICAL ACTIVITY
INTERCELLULAR JUNCTIONS• TIGHT JUNCTIONS – SECTIONS OF
ANIMAL CELL MEMBRANE WHERE 2 NEIGHBORING CELLS ARE FUSED SO MEMBRANES BECOME WATER-TIGHT
• DESMOSOMES – FASTEN CELLS TOGETHER STRENGTHENING THEM
• GAP JUNCTIONS – PROVIDE CHANNELS BETWEEN ADJACENT ANIMAL CELLS WHERE IONS, SUGARS, AND OTHER SMALL MOLECULES CAN PASS
STRUCTURES ASSOCIATED WITH PLANT CELLS ONLY
CENTRAL VACUOLE• STORES AND BREAKS DOWN
SOME WASTE PRODUCTS• IT CAN TAKE UP AS MUCH AS 80%
OF
THE CELL
CHLOROPLASTS• FOUND IN PLANT AND ALGAE
CELLS• SITES OF PHOTOSYNTHESIS
CELL WALL• PROTECTS THE PLANT AND HELPS
MAINTAIN ITS SHAPE• PRIMARY COMPONENT
IS THE CARBOHYDRATE
CELLULOSE
PLASMODESMATA• CHANNELS THAT PERFORATE
ADJACENT PLANT CELL WALLS AND ALLOW THE PASSAGE OF SOME MOLECULES FROM CELL TO CELL
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