Transport of Across Membrane Flashcards
(33 cards)
Atoms bind together to make _____
Molecules
____ are composed of simple sugars
Complex carbohydrates
Lipids are composed of _____ plus a _______
fatty acids, polar head`
What are the backbones of lipids made of?
Glycerol
This is the hydrophilic part of lipids
Polar head
This is the hydrophobic part of lipids
Fatty acid tails
____ are long chains of amino acids bound together
Proteins
Nucleic acids are composed of chains of __________.
nucleotides
These are building blocks of proteins
Amino acids
What are complex carbohydrates composed of?
Proteins, lipids, and some complex carbohydrates
Why is it called the Fluid Mosaic Model?
It refers to the mixture of lipids and intrinsic proteins in the membrane
Membrane components:
Lipid bilayer, proteins
WHY DO THE FATTY ACID TAILS OF PHOSPHOLIPIDS POINT TOWARD EACH OTHER IN THE MEMBRANE?
They are non-polar, so they are hydrophobic.
What does the final shape of the protein determine?
Its function.
What conditions can denature proteins?
Extreme temperatures
Two types of transport of materials
Passive transport and energy-consuming transport
Processes that are considered passive transport:
Simple diffusion
Facilitated diffusion
Osmosis
Processes that are considered energy-consuming transport: transport:
Active transport
Exo/Endocytosis
The movement of molecules in solution from a high
concentration of that molecule in the direction of a
low concentration
Diffusion
When does movement of molecules stop in diffusion?
When equilibrium is
reached.
WHY DOES PASSIVE DIFFUSION THROUGH THE LIPID LAYER ONLY OCCUR WITH GASES AND SMALL, LIPID-SOLUBLE MOLECULES?
. These substances are nonpolar, and so is the lipid layer.
Why are channel proteins necessary to move hydrophilic ions through the membrane?
Ions are charged; they cannot go through a nonpolar lipid layer.
Process of passive transport by facilitated diffusion
1 Carrier protein
has binding site
for a specific
molecule.
2 Molecule
enters binding
site.
3 Carrier protein
changes shape,
transporting
molecule across
membrane.
4 Carrier protein
resumes original
shape.
The diffusion through a semipermeable membrane.
Osmosis