Download The Cell in Action

The Cell in Action
For the cells that make up your body and the body of every other living thing to survive they must be constantly
at work. Never a dull moment in a cell.
For everything to run smoothly, some important processes must be in place. If they don’t work, you don’t
work!!!
Diffusion: the movement of particles from an area of high concentration to an area of low concentration. This
does not require energy (ATP)
Osmosis: the diffusion of water across a cell membrane
Movement of Small Particles
Passive Transport: particles move from an area high concentration to an area of low concentration through
proteins embedded in the cell membrane. This does not require energy (ATP).
Active Transport: particles move from an area of low concentration to an area of high concentration through
proteins embedded in the cell membrane. This process does require energy (ATP).
Movement of Large Particles
Endocytosis: cell membrane surrounds a particle & encloses it in a vesicle & is brought into the cell
Exocytosis: vesicle forms at the endoplasmic reticulum or Golgi complex and carry the particles to the cell
membrane for export from the cell (leave the cell)
Cell Energy
The vast majority of the energy that fuels life on Earth comes from the sun. How do we get access to that
energy…not solar panels…photosynthesis!
Photosynthesis: process by which plants capture the energy in sunlight & use it to convert CO2 (carbon
dioxide) & H2O (water) into C6H12O6 (sugar) and O2 (oxygen) .
The chlorophyll in the chloroplast absorbs this light energy.
Photosynthetic Equation
6CO2 + 6H2O + light energy
C6H12O6 + 6O2
Plants are so good at photosynthesis that we use them for food such as fruits, vegetables and grains. We
either eat the plants directly or we eat something, like a cow, that ate the plants for us. And not only that, you
may have noticed the nice bi-product of photosynthesis that we use every second of our lives…oxygen!
Now, how do we get energy from food?
Cellular Respiration: process of breaking down food in the presence of oxygen to release its stored energy &
convert it into ATP (the form of energy that cells can use).
The mitochondria of both plant & animal cells perform cellular respiration.
Cellular Respiration Equation
C6H12O6 + 6O2
6CO2 + 6H2O + energy (ATP)
**Photosynthesis requires the carbon dioxide produced by Cellular Respiration, which requires the
oxygen produced during photosynthesis.
How do we get more cells to take care of all this work???
Mitosis & the Cell Cycle!!!!
The Cell Cycle: 1. Cell parts are copied (Interphase)
2. Mitosis (4 Phases)
3. Cytokinesis
1. Interphase is when the cell organelles and genetic material is being duplicated so that when the
original/parent cell divides, the new/daughter cell gets all the same cell material, resulting in 2 identical
cells.
2. Mitosis (4 phases)
Phase 1(Prophase): nuclear membrane dissolves, chromosomes condense, centrioles move to opposite ends
of cell and fibers from between them and the centromeres.
Phase 2(Metaphase): the chromosomes line up at the center of the cell
Phase 3(Anaphase): the chromatids separate & are pulled to opposite sides of the cell by the fibers attached
to the centrioles.
Phase 4(Telophase): the nuclear membrane forms around the 2 sets of chromosomes, they unwind and the
fibers disappear
3. Cytokinesis occurs next and is the splitting of the cytoplasm. The result is 2 identical cells now back at
the beginning of the cell cycle.
***binary fission is how prokaryotic cells divide. They simply copy their DNA & divide into 2 cells