BP Exam 2- membrane bioenergetics

controlling movement of substances that cannot just move across is critical for

cell metabolism

passive and facilitated diffusion stops when

there’s no concentration gradient

facilitated diffusion helps larger molecules with _____ but has _____ energy requirements

carrier proteins or channel, no

concentration gradient is formed when molecules are not at

equilibrium

speed of passive diffusion is only dependent on

concentration gradient, no metabolic activity

specific carrier protein in facilitated diffusion membrane

permeases

facilitated diffusion is faster than passive because of ____ but it’s limited by

enzymes, channels available

permeable to all __ soluble molecules

water

H+ and OH- can’t

pass freely

uniport system

solute through carrier without other ions (active) (one way)

active symport

solutes moved in same direction through carrier

antiport active

moving two solutes opposite ways in one carrier (na/k pump)

primary active transport is coupled with

atp hydrolysis

carrier protein on outer surface has _____ binding affinity for substrate

high

the protein substrate complex is modified with

atp

some active transports involve whta proteins

binding

some active transports get energy from what force

proton motor force

group translocation usually covalently ____ the substrate and pairs with ___

modifies, metabolism

phosphoenol pyruvate (PEP) provides energy for

phosphotransferase system

in PTS system enzyme I is

cytoplasmic protein

in PTS system HPr is ___ that gives phosphate to __

histidine phosphocarrier that gives phosphate to enzyme II

Enzyme II C in PTS

phosphporylates sugar in cell

cAMP is increased by ___ from PTS

PEP

when glucose is available, phosphate is transferred to

glucose

when glucose is not available, phosphate goes to ____ and __ is made

adenyl catalase, camp

gram - outer membrane is impermeable to molecules greater than ___ and ___

600, hydrophobic

two systems that move large proteins from cytoplasm to OM

tat and sec

sec translocates ___ proteins and tat moves ____ proteins

unfolded, folded

export ___, secretion ___

in, out

type III secretory system uses ___ structures for direct transfer to eukaryotic host. pathogenic bacteria use a ____

needle-like, injectosome

type I ss uses ____

atp

type II ss is a general ___ pathway and utilizes signal __

secretory, peptides

tat and sec: n domain

basic region

tat and sec: h domain

central hydrophobic core

tat and sec: c domain

cleaves leader seq

sec pathway: secA ___, secB ____, secYE

cytoplasmic ATPase, binds to prevent folding, translocon

tat pathway is energized through

transmembrane proton electrochemical gradient

tat signal peptides have a conserved motif at what region

N-region

tat signal peptides are ____ hydrophobic than sec targeting signals

less

tat proteins have a twin ___ pair

arginine

tat signal peptides have ___ residues in c region. not found in sec c region

basic

tat signals are ___ than sec

longer

tatA operon in e. coli codes for

tatABCD, tatE

TatA, B, C, D, and E are proposed to have a ______ spanning alpha-helix

at the ___ terminus

membrane, N

Deletions of tatA or tatE lead to a ________ in the export of a range

of Tat substrate proteins

decrese