Textbook Notes (381,336)
CA (168,503)
UTSC (19,326)
BIOD27H3 (42)
Chapter 5

Textbook notes-Chapter 5 Membrane_Dynamics

3 Pages
76 Views

Department
Biological Sciences
Course Code
BIOD27H3
Professor
Ingrid L.Stefanovic

This preview shows page 1. Sign up to view the full 3 pages of the document.
Chapter 5 ± Membrane Dynamics BGYB30
Because of the free movement of water, the extracellular and intracellular compartments can reach a
state of osmotic equilibrium, in which the total amount of solute per volume of fluid is equal on the two
sides of the cell membrane. At the same time, however, the body is in a state of chemical
disequilibrium, in which the major solutes are more concentrated in one of the two body compartments
than in the other.
Example:
-> Na+, Cl- and HCO3
- are more concentrated in extracelullar fluid than in intracellular fluid.
-> Whereas, K+ are more concentrated inside the cell.
-> Ca2+ is more concentrated in the extracelullar fluid than in the cytosol, although many cells store Ca2+
inside organelles such as the endoplasmic reticulum and mitochondria.
- The inside of the cell is slightly negative relative to the extracelullar fluid.
- Homeostasis is not the same as equilibrium. The intracellular and extracelullar compartments of the
body may be in osmotic equilibrium, but they are also in chemical and electrical disequilibrium.
* dZ]voo(oµ]v]]v]Z(}uZÆoµoo(oµ]ÇZ/&[Z]PZ}vv]}v
of K+ ion and low concentration of Na+, and Cl- ions.
Diffusion:
- Cell membranes are selectively permeable; the lipid and protein composition of a given cell membrane
determines which molecule will enter the cell and which will leave.
- The size of the molecule and its lipid solubility influence its movement across cell membranes.
- Passive transport }v[µ]Z]vµ}(vPÇ
- Active transport requires the input of energy (e.g. high-energy phosphate bond of ATP)
- Diffusion is the movement of molecules from an area of higher concentration of the molecules to an
area of lower concentration of the molecules.
1- Diffusion is a passive process
2- Molecules move from an area of higher concentration to an area of lower concentration (along
a chemical gradient)
3- Net movement of molecules occurs until the concentration is equal everywhere
4- Diffusion is rapid over short distances but much slower over long distances
5- Diffusion is directly related to temperature (higher temp, molecules move faster)
6- Diffusion rate is inversely related to molecular size (the larger the molecule, the slower its
diffusion)
- Diffusion is the passive movement of uncharged molecules down their concentration gradient due to
random molecular movement.
- Diffusion directly across the phospholipids bilayer of a membrane is called simple diffusion.
Protein-mediated Transport:
- Simple diffusion across membranes is limited to lipophilic molecules.
- The vast majority of solutes move across membranes with the help of membrane proteins, a process
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
Chapter 5 Membrane Dynamics BGYB30 Because of the free movement of water, the extracellular and intracellular compartments can reach a state of osmotic equilibrium, in which the total amount of solute per volume of fluid is equal on the two sides of the cell membrane. At the same time, however, the body is in a state of chemical disequilibrium, in which the major solutes are more concentrated in one of the two body compartments than in the other. Example: + - - -> Na , Cl and HCO a3e more concentrated in extracelullar fluid than in intracellular fluid. -> Whereas, K are more concentrated inside the cell. 2+ 2+ -> Ca is more concentrated in the extracelullar fluid than in the cytosol, although many cells store Ca inside organelles such as the endoplasmic reticulum and mitochondria. - The inside of the cell is slightly negative relative to the extracelullar fluid. - Homeostasis is not the same as equilibrium. The intracellular and extracelullar compartments of the body may be in osmotic equilibrium, but they are also in chemical and electrical disequilibrium. * @Z]L oooo] L]Z]L2]ZZ}KZ oooo]Z [ZZ]2Z }L L]}L + + - of K ion and low concentration of Na , and Cl ions. Diffusion: - Cell membranes are selectively permeable; the lipid and protei
More Less
Unlock Document


Only page 1 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit