Biology 241 Topic 4 Flashcards
What is facilitated diffusion?
The use of tunnel shaped proteins in the membrane to allow diffusion down the concentratiion gradient
What are 4 characteristics of facilitated diffusion
-Each channel is substrate specific
-Does not need ATP (energy)
-[gradient] determines rate
-can be reversed
What uses facilitated diffusion?
large polar molecules or ions
Whats the difference between channel proteins and carrier portein in facilitated transport/diffusion?
Channel: |o| or }o{ (straight path)
Carrier: \o/ -> |o| -> /o\ (Waits for solute to bind to then changes shape
What is the difference between simple and facilitated diffusion graphed?
Facilitated approaches a maximum while simple is a psoitive linear incline
What type of environment do cells live in… and what does mean in terms of the cell?
Dilute, the cell needs the to keep the molecules on the inside rather than diffuse towards the environment
How do cells establish a concentration gradient? What does this require?
The solutes must move away from equlibrium, thus requiring an energy source
What is Primary Active Transport?
When a highly specific protein pump uses ATP to transports a solute against its [gradient] (low to high) and across the membrane.
What is Secondary Active Transport?
A highly specific protein that transports solutes up the [gradient] (low to high). Generates power by having a different solute move down its own [gradient]
What is the difference between symporters and antiporters in secondary activde transport?
Symporters: Both solutes move in the same direction
Antiporters: Solutes move in opposite directions
What are the forms of Passive transport? (aside osmosis)
Simple diffusion and Facilitated Diffusion
What solutes use simple diffusion?
Small hydrophobic (non-polar) and small polar (hydrophilic) solutes
What is simple diffusion?
Direct diffusion across the phospholipid bilayer down the concentration gradient (high to low)
What does a large concentration gradient cause in terms of simple diffusion?
A faster rate of diffusion
Why do phospholipids form bilayers in water?
Hydrophobic tails move inwards away from water while the Hydrophilic head move outwards toward the water
E.g.
OOOOOOOOO
|||||||||||||
OOOOOOOOO
What are lipids?
Hydrophobic molecules comprised mostly of carbon and hydrogen molecules
What are the three Biological lipids?
-Triglycerides(Triacylglycerolds)
-Phospholipids
-Sterols
What is the function of triglycerides
Energy Storage
Which 2 Biological Lipids are bulding blocks for the cell membrane
Phospholipids and Sterols
Fatty acids are the building blocks of which biological lipids
Triglycerides and phospholipids
What are Fatty Acids comprised of?
Hydrocarbons with a Carboxyl group
Which one does not have any C=C bonds and which has one or more C=C (C=C stands for carbon carbon double bond):
-Saturated Fatty Acid
-Unsaturated Fatty Acid
-Saturated FattyAcid has no C=C
-Unsaturated Fatty Acid has one or more C=C
What increases the fluidity of a membrane?
-increase tempurature
-more unsaturated fatty acids
-short chains in the fatty acid tails
-cholesterol
Why is the Lipid Bilayer considered fluid?
Each phospholipid is independant and not attached to one another (able to move freely along the plane of the membrane)
