membrane proteins

Membrane that differ in function also differ in

Their protein content

What do proteins transport

Chemicals and information

Integral membrane proteins

Embedded in the hydrocarbon chains of membrane lipids, and they can be release only when the membrane is physically disrupted

Peripheral membrane proteins

Bound to the head group of lipids or the exposed portions of integral membrane proteins by electrostatic and H bond interactions

Alpha helices or beta sheets in the hydrophobic region of the membrane have what type of amino acids

Hydroponics

Alpha helices or beta sheets in the water soluble region of the membrane have what type of amino acids

Ionic

What type of amino acids do loops and turns have

Ionic bc facing aqueous environment

What factors determine whether a small molecule will cross a membrane

The concentration gradient of the molecule across the membrane or the molecules solubility in the hydrophobic environment

What method of transport do lipophillic molecules use

Simple diffusion

What method of transport do polar molecules use

Passive transport, active transport, facilitated transport

Passive transport

Movement with the concentration gradient with no added energy

Facilitated diffusion

Diffusion through a protein channel with no added energy

Active transport

Movement against the concentration gradient with added energy

Primary transporters

Hydrolyzes ATP and transports molecules against their gradient

Secondary transporters

Couple transport of molecules against the concentration gradient to transport of a molecule with its concentration gradient

Ion channels are what type of transport

Passive

How much faster is ion transport rates compared to ion pumps

1000 times

Voltage gated channels

Open in response to changes in membrane potential

Ligand hated channels

Opened in response to the binding of small molecules such as neurotransmitters

How does an ion move through a channel

Ion has hydration shell that is removed as it travels down the channel. The water molecules are replaced by oxygen atom interactions lining the selectivity filter. As the ion gets closer to moving inside, the oxygen breaks its bond with the ion and water reforms shell

How are ion channels selective

Structure of the ions determines specificity. Larger ions are too big to enter channel and smaller ions can’t interact with the selectivity filter

Na-K ATPase

Hydrolysis of ATP provides energy needed for the active transport of three Na out and two potassium in against their gradients

Na-K ATPase and SGLT

ATPase move Na outside against its concentration gradient and there is high amounts outside. SGLT uses Na gradient to move Na and glucose inside