1. Warm-Up (9/21)
On the piece of white paper from the back, answer the following question.
Describe how the allosteric inhibitor below will inhibit (deactivate) the enzyme. Describe in detail. Like, molecular detail. Like, maybe, using
using the word “R group.” Do not just say “…and then the active site won’t work.” That would be lazy, and you’re in the awesome zone, pal.

2. Surface Area: Revisited
Cells have internal compartments lined with phospholipid bilayers like the plasma membrane.

3. Surface Area: Revisited
How do membrane-bound organelles contribute to a cell’s size?

4. common ancestor of all life
Life As We Know It
No membrane-bound organelles
Has membrane-bound organelles
Stupid, pathetic, worthless, uncivilized, crappy, and VERY SMALL.
Diverse, awesome, and MUCH LARGER.
2 – 8 μm in diameter
up to 100 μm in diameter
common ancestor of all life

5. Surface Area: Revisited
How do membrane-bound organelles contribute to a cell’s size?
Answer!
They increase the surface area, allowing cells to be bigger.

6. Internal Membranes
Membrane-bound organelles also help organize chemical reactions.
enzymes
What good is an enzyme if the substrates are in a different place?!?!?!
substrates

7. Example: The Lysosome “Trashcan”
The lysosome is a membrane-bound organelle that contains digestive, metabolic enzymes to break up trash in the cell.
Lysosome enzymes are called “hydrolytic” because they cause hydrolysis. What is hydrolysis the opposite of?

8. Active Transport
Transport across a membrane that requires energy, usually using the energy molecule ATP.
What kind of biomolecule does this look like, and how is it different from what you’ve seen?

9. Active Transport
Moves molecules or ions (charged particles) from LOW concentration to HIGH concentration.

10. Independent Practice
Look at Figure 7.18 on p. 136 and read the caption, then answer questions 1 and 2 in the yellow box on page 138.
“Sir, what’s a cotransporter?”
“Well the word is in bold on page 137, so maybe you should read about it.”

11. Closure (9/21)
Explain two ways internal membranes facilitate complex cellular interactions. What would happen if the lysosome was not compartmentalized by a membrane?
Scale from 1-10