Chapter 1 1 2 Cells Cells cells and

Chapter 1 1. 2 Cells!

Cells, cells and more cells! Living things are made up of cells! Cells are the basic UNIT OF LIFE Cells have different parts called “structures” that have different jobs. We will mostly study animal and plant cells

Cell Facts… How many cells do we have in our body? 50 – 100 trillion (that’s 50 million!) That means that if you lined all your cells up one after another they would stretch around the Earth 47 times!!! If you could count 1 cell each second, it would take you 2600 years!!!

Cells Plant and animal cells contain many of the same structures but there are some differences. Only PLANT cells have - cells walls and - chloroplasts. Let’s look at the various cell structures….

Cell Structures • First let’s look at structures found in both animal and plant cells… 1. Cell Membrane - “the security guard” - like skin for the cell - it protects the cell - regulates particles coming in and out

Cell Structures 2. The Cytoplasm • “the jelly” • inside of the cell contains a jelly-like substance • supports all the structures in the cell • also contains water that the cell needs! Like Jello!

Cell Structures Smaller structures in the cell that have a specific function are called “organelles” 3. The Nucleus • “the brain” • controls the cell’s activities • the DNA for the cell is also found inside the nucleus

Cell Structures 4. Mitochondria (singular = Mitochondrion) • The “energy maker” • Makes energy so the cell can carry out its activities • Uses a process called cellular respiration to make energy

Cellular Respiration How cellular respiration works: We take in food (glucose) and our cells use this glucose to make ENERGY! Glucose + Oxygen ENERGY + CO 2 + H 2 O

Cell Structures Protein plays many important roles in living things… What is protein? o It’s an essential nutrient that WE need to build muscles, hair, skin, and nails. o CELLS need it to build various structures and carry out specific functions

Cell Structures Our cells have organelles in charge of making, moving and storing protein… 5. Ribosomes • little “protein factories” • they assemble the proteins • small round structures • found in the cytoplasm and on the ER

Cell Structures 6. Endoplasmic Reticulum • Looks like a fan or an (ER) accordian • Network of channels covered by a membrane • Proteins pass through the ER after they are assembled by the ribosomes ER is always close to the nucleus!

Cell Structures 7. Golgi Body • “like Fed-EX” • Proteins go through the ER to the Golgi body • Here the proteins are sorted, packed up in vesicles and sent around (or out of) the cell

Cell Structures 8. Vacuoles • “storage sacs” • Temporarily store – Waste – Water – Nutrients Large plant cell vacuole

Vacuoles in Plant & Animal Cells Animals cells… Have several small vacuoles Plant cells… Have one large vacuole (usually)

Cell Structures 9. Lysosomes • “recycling depots” • Recycle organelles that have worn-out • Have digestive enzymes that break down food, waste and worn-out cell parts

Cell Structures…Plants Only! 10. Cell Wall • “the city wall” • Surrounds the cell membrane • Tough and rigid • Gives the cell a box-like shape • Main jobs: – Protects the cell – Gives support

Cell Structures…Plants Only! 11. Chloroplasts • “food makers” • Look like stacked green pancakes • Trap the sun’s energy • Make oxygen and food for plant in a process called “photosynthesis”

Photosynthesis Energy + CO 2 + H 2 O Food + O 2 This is a very important process… Plants take in carbon dioxide that we exhale and give us oxygen to breathe!

RECAP! Important differences between plant and animal cells: 1. Plant cells have CELL WALLS 2. Plant cells have CHLOROPLASTS 3. Plant cells have much larger VACUOLES