Chapter 4 Notes
I. Exchange with the Environment
cells must get energy, raw materials & get rid of waste
A. What is Diffusion?
movement from area of high concentration to area of low concentration (from a lot to a little/balances
uses no energy
1. Diffusion of Water
Water-necessary for life
Osmosis=movement of water from lot to little across a semipermeable (lets some things in/keeps some things out) membrane/balances/uses no energy
water & salts in plasma/in red blood cells (in balance)
if red blood cells put into pure water, water would flow in and cell would burst
if red blood cell put into salt water, cell would shrivel
B. Moving Small Particles
particles move thru channels (proteins) in cell membranes
· passive transport-diffusion & osmosis, uses no energy(from lot to little)
· active transport-uses energy, from little to lot
·
C. Moving Large Particles
large particles move by endocytosis & exocytosis, use energy
1. Endocytosis
active transport of large particles into the cell
2. Exocytosis
active transport of large particles out of the cell
II Cell Energy
All cells require energy
A. From Sun to Cell
Sun - source of most life energy
1. Photosysnthesis
Chlorophyll(pigment) in chloroplast catches sun’s energy
There mixes CO2 + H2O to produce food(glucose sugar)
2. Getting Energy from Food
B. Getting Energy from Food
Cellullar respiration-uses O2 to break down food to get energy
Fermentation-uses NO O2 to release energy
.1 Cellular Respiration
Breathe to get air for Cell. Resp.
In mitochondria, O2 mixes with sugar/glucose to release ATP(energy)
2. Connection Between Photosynthesis and Respiration
3. Fermentation
In animal cells IF O2 has been used up.
