HOMEOSTASIS AND CELL PROCESSES HOMEOSTASIS BALANCE CELL WANTS

HOMEOSTASIS AND CELL PROCESSES

HOMEOSTASIS • BALANCE • CELL WANTS TO STAY CONSTANT EVEN WHEN ITS ENVIRONMENT IS CHANGING • ALLOWS CELLS TO CARRY OUT LIFE PROCESSES SUCH AS GETTING ENERGY, DIVIDING, TRANSPORTING MATERIALS • CELLS IN MULTICELLULAR ORGANISMS NEED EACH OTHER TO MAINTAIN

HOW DO CELLS GET ENERGY? • CELLS NEEDS ENERGY TO PERFORM CELL FUNCTIONS • ENERGY COMES FROM FOOD • PLANTS MAKE FOOD THEN BREAK THE FOOD DOWN INTO ENERGY • PLANTS, ANIMALS, AND OTHER ORGANISMS BREAK DOWN FOOD FOR ENERGY

PHOTOSYNTHESIS • TAKES PLACE IN CHLOROPLASTS • WATER + CARBON DIOXIDE + SUNLIGHT SUGAR + OXYGEN

CELLULAR RESPIRATION • TAKES PLACE IN MITOCHONDRIA • USES OXYGEN TO BREAK DOWN FOOD TO MAKE ATP ENERGY • SUGAR + OXYGEN WATER + CARBON DIOXIDE + ATP

HOW DO CELLS DIVIDE? • UNICELLULAR ORGANISMS REPRODUCE BY DIVIDING • MULTICELLULAR ORGANISMS GROW WHEN CELLS DIVIDE • DNA IS COPIED AND SPLIT EVENLY • THE NUCLEUS SPLITS (MITOSIS) TO FORM TWO NEW NUCLEI

HOW DO CELLS EXCHANGE MATERIALS? • MATERIALS ENTER AND LEAVE THE CELL THROUGH THE MEMBRANE • PASSIVE TRANSPORT TAKES PLACE WITHOUT USING ENERGY • 2 TYPES OF PASSIVE TRANSPORT: DIFFUSION AND OSMOSIS

DIFFUSION • MOVEMENT OF PARTICLES FROM AREAS OF HIGH CONCENTRATION TO AREAS OF LOW CONCENTRATION

OSMOSIS • THE DIFFUSION OF WATER THROUGH A SEMI-PERMEABLE MEMBRANE • SEMI-PERMEABLE MEANS ONLY SOME SUBSTANCES CAN PASS THROUGH • FLUIDS IN AND AROUND CELLS ARE MOSTLY WATER

ACTIVE TRANSPORT • TAKES PLACE WHEN CELL NEED TO MOVE MATERIALS FROM LOW CONCENTRATION TO HIGH CONCENTRATION • REQUIRES ENERGY

ENDOCYTOSIS VS. EXOCYTOSIS • COPY THE DEFINITIONS AND PICTURES FROM P. 208 IN YOUR TEXTBOOK