Study Guides (390,000)
CA (150,000)
Western (10,000)
PHYSIO (300)
Study Guide

Physiology 3120- Final Exam Guide - Comprehensive Notes for the exam ( 52 pages long!)


Department
Physiology
Course Code
PHYSIO 3120
Professor
Tom Stavraky
Study Guide
Final

This preview shows pages 1-3. to view the full 52 pages of the document.
Western
Physiology 3120
Final EXAM
STUDY GUIDE

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

September 13th, 2017
Physiology 3120
Lecture 2: Membrane Transport Mechanisms:
Simple Diffusion:
The movement of molecules due to their random thermal motion
Unless they are at absolute zero
Water moves at 2,500 kph
Glucose moves at 850kph
o Slower because it is a much larger molecule
Molecules move from areas of high concentration to low, this is the driving force
Molecules spread out until chemical (dynamic) equilibrium is reached (no net
movement)
Once there is no concentration gradient there is no more net movement
Diffusion Distance:
Diffusion is not efficient over “long distances”
Do you think you can change this Diffusion Distance in the human body? YES
Vasoconstriction or vasodilation
Cells can getting bigger
Make more capillaries – so more cells can diffuse
o Angiogenesis: the production of more blood vessels (occurs with exercise)
§ Less exhaustion
Diffusion Through Cell Membrane:
Substances must non polar (lipid soluble) in order not penetrate the lipid (fatty acid tail) region
of the lipid bilayer
Non polar molecules include: O2,
CO2, fatty acids, steroids and
some alcohols
Driving force is still the
concentration gradient
Time exponentially increases as the distance increases
Thus travelling long distances is incredibly
inefficient
O2 takes 20ms to go 10um
O2 takes 7 hrs to go 1 cm!
*Cells are within 25-50 µm of blood vessels
This works since this is not a super long
distance
Note that: Whenever diffusion is
involved the driving force is the
concentration gradient
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Diffusion again occurs until we reach equilibrium where there is no net movement again
Rate of diffusion can be predicted by Fick’s Law
r is the radius of the molecule trying to diffuse through
Why is there a (-) before kT?
Because the concentration gradient of the solute decreases: a negative slope
The other negative is there to cancel out the negative slope
Which of the following would increase the rate of diffusion of a very small lipid soluble
molecule through a cell membrane?
A. Increasing the viscosity of the medium through which the molecule is diffusing
B. Increasing the amount of ATP available for transport
Note since the process is passive it does not require ATP
C. Increasing the total surface area for diffusion
D. Increasing the diffusion distance
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version