Fri Sept 15
•
Over-riding goal: Wrap up Worksheet, note error, and move
deep into membrane transport
•
Learning Objectives from the Syllabus:
─
…explain the processes of diffusion and osmosis; apply these
concepts to predicting changes in cell volume caused by exposure to
different solutions; use this knowledge to evaluate a patient’s hydration
state based on his/her hematocrit. What other factors might affect
hematocrit? How could these be eliminated as possible factors?
─
…compare and contrast facilitated diffusion with active transport
─
...compare and contrast primary active transport and secondary active
transport. Provide an example of each;
─
...outline the contributions of various types of membrane transport in
transepithelial transport, such as that used to transport sodium,
glucose and/or water across a layer of tissue, rather than just a cell
membrane
•
Burn 1 ATP per triglyceride
•
2nd - last round of beta-ox.  1 FADH2
and 1 NADH  8 each from beta ox
total
•
Each round  1 acetyl-CoA  9 total
•
Each Acetyl CoA  3 NADH, 1 FADH2
& 1 ATP (indirect) in Krebs
•
Do this 9X  9 Acetyl CoA
─ X 3 NADH/cycle = 27 NADH;
─ X 1 FADH2/ cycle = 9 FADH2;
─ X 1 ATP/Krebs = 9 ATP
•
Total NADH = 27+8 = 35 NADH
•
Total FADH2 = 9 + 8 = 17
•
Total ATP (so far) = 9 – 1 = 8
•
Ox Phos  35 NADH X 3 ATP/NADH +
17 FADH2 X 2 ATP/FADH2= 139 ATP
•
Net ATP = 139 + 8 = 147
1st beta ox
Each happens 8 X
• Pantothenic acid is one of the B-complex
vitamins and as such is one of many
essential nutrients required for normal
functioning of our metabolic processes.
─A) What is an essential nutrient?
─B) In terms of cellular respiration, what is the
importance of pantothenic acid?
In your groups...
1.
Define Diffusion
2.
Define Osmosis
3.
The membrane in the vessel on the
right is permeable only to I; when I
solution is added to side 1...
4.
a.
what will happen initially?
b.
after a long period of time?
If the membrane is only permeable to
water and you add a lot of I to side 1...
a.
Does I cross the membrane?
b.
Is there a net movement of water across the
membrane?
c.
If so, in which direction? Explain.
1
2
In your groups...
d.
What happens to the water level on each
side?
e.
The difference in fluid level on the 2 sides
has a mass;
i.
ii.
multiplied by the force of gravity we end
up with a force called weight;
when applied to the surface area of the
vessel and the membrane, we end up
with what?
11
22
6.
Human blood plasma has a
concentration of impermeable solutes
~300 mOsm. When a “blood???”
sample from an alien captured and kept
at “Area 51” was mixed with human
blood plasma the hematocrit (adjusted
for dilution) dropped from 60 to 42.
a.
What happened to the volume of the alien
blood cells? How/Why?
b.
Does this data suggest that human blood
plasma is hypo-, iso-, or hypertonic relative to
alien plasma?
c.
Define the term that you used for the prior
answer.
There are 2 forms of facilitated
transport across membranes:
Active and Passive
The difference is the requirement
for ATP
Passive Transport: Facilitated Diffusion
•
Basic mechanism
7. So then...
a. What makes this “facilitated’?
b. How is this a form of diffusion and as
such what is the driving force behind it?
c.
In which direction are substances
transported this way?
8. ~4 sessions back we talked about
modulating protein function. Identify
the specific type of modulation
shown here and explain.
Mon, Sept 18
• Today: Wrap up transport = End of Exam
1 material
• Wed: Start intracellular signaling/signal
transduction
• Lab: Recitation... TAs are making up
questions... Answer as “exam” in lab...
Review questions immediately after...
Other questions.
• Homework:
─Buy a stapler
─Type
• Group Work: Lab groups; only the people
you work with in lab... 3 max; if there are 4
in your group, split in ½ for class work
• Assignments that don’t conform to these
requirements will not receive credit.
There are 2 forms of Active
Transport: 1° and 2°
1° Active Transport
•
Basic Mechanism
9. How is this different from facilitated diffusion?
10. What type of protein modulation is involved?
Inter-membrane Space (High Proton concentration)
Mitochondrial Matrix (Low Proton Concentration)
Example: Na+/K+ ATPase
• Responsible for Na+/K+ asymmetry across
the plasma membrane.
• Per cycle:
= example of counter
transport
Opposite of cotransport
2° Active Transport
•
Basic Mechanism
11. Driving force?
12. Direction of movement?
13. Why Secondary?
•
Note: Typically Na+ is the
Energy Ion
─ E.g., Na+/H+ exchange,
Na+/K+/2Cl- co-transporter
─ E.g., Na+/Glucose co-transporter
Epithelial Transport
14. What does activity of 1 do to [Na+] in the cell?
15. How does this result in the arrow pointing to the right in “2”
16. How does the activity of “1” lead to the movements of water
indicated by the arrows?
Endocytosis and Exocytosis Move
Materials in Bulk
• Define Endocytosis
& ID a situation in
which it might be
used
• Define Exocytosis
& ID a situation in
which it might be
used