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

what does secB do

blocks folding in sec

when are cofactors added in sec and tat

after sec, before tat

twin arginine motif is in what pathway

tat

direct fuel of sec pathway and what inhibits it

secA, azide

direct fuel of tat

pmf

decisive knockouts of each pathway

secA, tatC

Export survives secA(ts) at 42 °C and a brief azide hit,

dies in ΔtatC, and the cytoplasmic GFP or cofactor

assay shows the protein was finished before crossing.

tat

Export dies at 42 °C or with azide, survives ΔtatC, and

the protein is protease-sensitive in the cytoplasm

sec

how is electrochemical potential generated

unequal distribution of protons

in proton motive force, electrons and protons are removed through ___ reactions and transported to electron ___

oxidative, electron

protons returning to the inside of the cell move toward the ___ pole, allows for ___ to be done

negative, work

chemiosmotic force is attributed to ___ and ___ activities

electric, chemical

the electron transport chain generates

proton motive force

electrical energy is from ___, chemical energy is from __

build up of protons and charge, concentration gradient

what is picked up from cytosol, translocated, and releases protons

quinone

menaquinone (vitamin K2) is used

during anaerobic and anaerobic respiration in gram positives and anaerobically in gram neg

nitrate is the final electron acceptor in

aerobic respiration

example of organic final electron acceptor

fumurate

flavoproteins and quinones carry

H+ and e-

iron-sulfur proteins and cytochromes carry

e-

when falvins are reduced, they carry

two e- and two protons

quinones are e- carriers on

lipids, hydrophobic

2 types of quinones

Ubiquinone and menaquinone

menaquinones are derivatives of ____ and are used in ____ and ____ respiration

vitamin K, fumurate and anerobic

iron sulfur proteins have a ______ spectra

e- spin resonance from unpaired e-

iron-sulfur protiens are usually in

clusters

prosthetic group of cytochromes

heme

in cytochrome, the e- carrier is

iron

which hemes are only in prokaryotes

cytochrome d and o

what accepts e- from dehydrogenases

quinones

reductases reduce e- ____ other than ___

acceptors, o2

cytochrome bo has ___ affinity for O2, and cytochrome bd has ___ affinity

low, high

coupling sites are where ____ reactions happen and ___ synthesis can happen

redox, atp

coupling site 1

nadh dehydrogenase to quinone

in site 2A, what happens

q cycle, quinone to cytochrome c

q cycle

quinone carries 2 protons and e-, releases proton to outside

site 2B

proton pumping from reduced quinone to O2

site 3A and 3B

cytochrome c —> O2

how many protons for one atp

2-3

f-type atp synthase has what structure

knob and stalk

f type knob BF1 has

catalytic subunits, on interior of cell, stick out

f type knob does what

synthesizes atp

f type stalk BF0 has

proton channel, in membrane

when oxygen is low, a ______ oxidase is used. when it is high a ______ oxidase is used

high affinity. low affinity

f type stalk acts as an

anchor

the atp synthase complex ____ during proton transport

rotates

F type atp synthase uses what to synthesize atp

proton reentry

respiration can generate

pmf