Lecture 2b: Nutrient Transport

Define: Uniport, symport, antiport

1. one substance one way

2. two substances the same way

3. one in while another goes out

______ transport uses the proton motive force and leaves the substrate unchanged

Simple

Group translocation uses ______ as its energy source and ______ the substrate as it crosses

PEP; chemically modifies (phosphorylates)

ABC transporters get their energy from ______

ATP

Lac permease is a ______ that brings lactose into E. coli together with ______

symporter; H⁺

what are the 3 components of an ABC transporter?

1. solute binding protein

2. integral membrane protein

3. ATP-hydrolyzing protein

In gram-negatives the solute binding protein is in the ______; in gram-positives it’s a ______ anchored to the membrane

periplasm; lipoprotein

The PTS moves ______, ______, and ______

glucose, fructose, mannose

saturation effect

transport level off once the transporters are fulland cannot transport additional solute