Class Notes (836,148)
Canada (509,657)
Biology (6,817)
Lecture 11

Lecture 11 - Water and Fluid Transport I - Principles

2 Pages
137 Views
Unlock Document

Department
Biology
Course
Biology 2601A/B
Professor
Graeme Taylor
Semester
Fall

Description
LECTURE 11 – WATER AND FLUID TRANSPORT I: PRINCIPLES Osmoregulation  Balancing water and ions in the cells and the body to allow physiological function  Principles to cells to organisms Water  Highly polar o Hydrogen bonding o High heat of fusion and vaporization o Large thermal capacity o Cohesion and adhesion  The universal solvent for life  Water interacts with other molecules – it creates a “shell” of bound water around many macromolecules (like proteins)  Keeps ions dissociated Water in Cells  Determines cell volume in animals o Cell volume is often the bottom level of regulation of water and ion balance  Determines cell turgor in plants o The positive pressure (turgor pressure) in plant cells that keep them turgid Moving Water  Osmotic potential – based on solute concentration  In living cells, positive pressure – turgor pressure – tends to push water out of the cell and negative pressure – tension – is what pulls water in cell of xylem  Moving water requires the creation of a gradient, and some ion pumps only work in one direction  Water cannot be moved actively as there are no active water transporters in plants – moves down pressure gradient in which it is referred to as a water potential (Ψ) and measured in MPa  Water moves towards the lower water potential  In determining the osmotic potential (s ), it is calculated as follows: Ψ = -RTc where R is the s s gas constant, T is the temperature and s is the concentration of the solute  Increasing solute concentration lowers water potential. By osmosis, water will move through a selectively permeable membrane in the direction of the highest solute concentration  Thus, increasing solute concentratio
More Less

Related notes for Biology 2601A/B

Log In


OR

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