Lecture Notes for Jan 20, 2009

Biology 212 with Mayfield at Iowa State University

About this deck

By: Betsy Salmon
Textbook:

Biology, 7th Edition (Book & CD-ROM)
Created: 2009-01-20
Size: 9 flashcards
Views: 2

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Diffusion
(4 answers)

the most important transport mechanism in cells
all molecules are in motion
random motions cause differences in concentration to become equalized over time
diffusion is the most important mechanism for molecules to move about in cells

Facilitated transport
(2 answers)

specific
always

All cells and many cellular structures are bounded by biological membranes
(6 answers)

membranes separate "inside" from "outside"
membranes are fluid (flexible), like the wall of a soap bubble
membranes are very thin
membranes consist of a phospholipid bilayer and proteins that modify bilayer properties
the two sides of a membrane are different
membranes also contain other lipids and some carbohydrates

Biological membranes are semipermeable
(4 answers)

some molecules can cross and some cannot
polar molecules and ions do not easily cross membranes
small molecules cross more easily than large ones
water molecules are polar and very small and some water does 'leak' across most membranes

Electrogenic (or hydrogen ion) Pump
(2 answers)

requires energy (usually ATP)
generates voltage across a membrane

Active transport
(3 answers)

transports specific molecules or ions across membranes from
involves specific binding of transported molecules to membrane proteins
requires energy

requires energy
(2 answers)

ATP
pH gradient

Osmosis
(4 answers)

water molecules move by diffusion
if other molecules (solutes) are dissolved in water they dilute the water
this causes water to move into areas of higher solute concentration, diluting the solute molecules and increasing the water concentration in that region
when there is a semipermeable membrane, this causes the volume, or pressure, to increase or decrease

Membranes regulate what molecules enter and exit cells
(2 answers)

passive transport (pores)
active transport (requires energy)

About this deck

By: Betsy Salmon
Textbook:

Biology, 7th Edition (Book & CD-ROM)
Created: 2009-01-20
Size: 9 flashcards
Views: 2

About StudyBlue

“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy