1. How do cells FUNCTION (work)?
Cell Physiology
How do cells FUNCTION (work)?
STERNGRR Processes take place at the cellular level!
Cell Transport
Photosynthesis
Cell Respiration

2. Cell Transport is a STERNGRR process
• Lets food in for NUTRITION
• Lets oxygen in for RESPIRATION
• Lets waste out for EXCRETION
Materials move in/out of cells through the cell membrane
The cell membrane is SELECTIVELY PERMEABLE
Phospholipid bilayer
Membrane protein

3. Types of Cell Transport Passive Cell Transport
Active cell transport
Does NOT require energy
Requires energy
Movement DOWN the
concentration gradient
Movement AGAINST the
High  Low
Low  High

4. Molecules move until they reach EQUILIBRIUM:
Diffusion
Diffusion is a type of Passive Transport
• Lets food in for NUTRITION
• Lets oxygen in for RESPIRATION
• Lets waste out for EXCRETION
Movement of molecules from a high to low concentration
Example:
Oxygen is moved from a high concentration in the lungs, to a low concentration in the blood
Molecules move until they reach EQUILIBRIUM:
An equal concentration on both sides of the membrane

5. Molecules move until they reach EQUILIBRIUM:
Osmosis
Osmosis is a type of diffusion
(a type of passive transport)
Movement of WATER molecules from a high to low concentration
Example:
In salt water, there is more WATER in the cell than in the surrounding environment, so water leaves the cells and they shrivel
Molecules move until they reach EQUILIBRIUM:
An equal concentration on both sides of the membrane

6. Cell Energy Processes include:
Photosynthesis
and
Cellular Respiration
Photosynthesis is a STERNGRR process
Cellular Respiration is a STERNGRR process
The two processes work together in a cycle!

7. Photosynthesis
Involves making FOOD (sugar/glucose) for nutrition
CO2 + H2O + sun  C6H12O6 + O2
REACTANTS PRODUCTS
Occurs in the CHLOROPLASTS of plant cells.
Uses the green pigment CHLOROPHYLL to capture light energy
Green light is reflected… all other wavelengths of light are absorbed by the plant.

8. Photosynthesis
What is going in and coming out of the plant?

9. They are 2 different things!
ATP
The food made in photosynthesis is used to make energy for cells!
Food is NOT energy!
They are 2 different things!
Organisms (including plants) must use this food to produce energy
Plants make food for all living organisms (sugar)
ATP is the energy molecule for cells
Adenosine P P P
Energy is stored in a chemical bond – when the bond is broken, energy is released!
Energy

10. Cellular Respiration
Involves using food made in photosynthesis for respiration, to make ATP for energy.
C6H12O6 + O  CO2 + H2O + ATP
REACTANTS PRODUCTS
Occurs in the Mitochondria of ALL cells

11. Cellular respiration can take place
WITH Or
WITHOUT
Oxygen!
Anaerobic respiration (fermentation) takes place when oxygen is NOT present
Aerobic respiration occurs when oxygen is present
Makes a LOT of ATP
Makes a little ATP
In plants and microorganisms:
Alcoholic fermentation
In animals:
Lactic acid fermentation