1. Ch 2.3 Plant and Animal Cellular Processes

2. Cellular Processes
whether we are asleep or awake, active or lounging on the couch, our cells are constantly working, transporting raw materials, converting energy and transporting energy, building proteins, and sending chemical messages

3. Transforming Energy all cellular activities need energy
mitochondria provide energy to the cell by transforming oxygen and sugar into carbon dioxide and water in a process called cellular respiration
cellular respiration occurs in both plant and animal cells
in plant cells, chloroplasts in the cells produce the sugar needed by the mitochondria in a process called photosynthesis

4. Processing and Transporting Materials
the endoplasmic reticulum makes proteins from raw materials that come through the cell and passes them to the Golgi apparatus
water, gases, and nutrients enter the cells through the cell membrane
materials move through the cytoplasm to the various organelles
lysosomes break down food and digest wastes
the Golgi apparatus processes protein molecules and secretes them outside the cell to be used elsewhere in the organism
All of this cellular activity is controlled by the nucleus!

5. Reproducing cells have a lifespan cells die because
amoebas live for ~2 days
human brain cells ~30-50 years
human red blood cells ~120 days
human skin cells ~20 days
cells die because
they have been damaged
they have not received enough water or food
they have reached the end of their lifespan
ROUGHLY 3 BILLION CELLS IN OUR BODIES DIE EVERY DAY!!

6. With all these cells dying every day, wouldn’t you expect multicellular organisms to shrink over time?

7. Reproducing
before the cell dies, it splits (through cell division) to create a replacement for itself
in animal cells, the nucleus first splits in two; then the membrane pinches near the middle to divide the cytoplasm, along with all its organelles, and ensures that each new cell has a nucleus
the two new cells are identical

8. Animal Cell Division

9. Reproducing
bin plant cells, instead of the cell membrane pinching the cell in two after the nucleus splits, a new cell plate develops across the cell to create a new cell wall between the two nuclei

10. Plant Cell Division