Respiration Flashcards
Respiration releases the energy stored in carbon compounds for cellular use, and generates – for biosynthesis
carbon precursors
Glycolysis - oxidize sugars involves reactions carried out by soluble enzymes in the –
cytosol and in the plastid
Sucrose is split into –
glucose and fructose and UDP-glucose
glucose-6-phosphate and fructose-6-phosphate –> triose phosphates called
glyceraldehydes-3-phosphate and dihydroxyacetone phosphate
Triose phosphates are oxidized to
phosphoenolpyruvate (PEP) → pyruvate
additional end product to pyruvate
malate
anaerobic respiration occurs when oxygen is unavailable such as in –
roots in flooded soils
fermentation occurs in
cytosol
fermentation – pyruvate to convert NADH to NAD+
reduce
fermentation results in – ATP per sucrose rather than 60 if citric acid cycle
4
Alternative to glycolysis for oxidizing sugars
pentose phosphate pathway
pentose phosphate pathway contributes more when plant cells become –
fully differentiated
PPP: Contributes more when plant cells become –
fully differentiated
6-carbon glucose-6-phosphate is oxidized to the 5-carbon ribulose-5-phosphate, releasing – and generating –
releasing CO2 and generating NADPH
Ribulose-5-phosphate is converted into –
3- to 7- carbon sugars
Inhibited by the accumulation of its products,
fructose-6-phosphate and glyceraldehyde-3-phosphate
fructose-6-phosphate and glyceraldehyde-3-phosphate are formed in chloroplast as part of the – cycle to produce ribulose
Calvin
Reactions of citric acid cycle are carried out by enzymes in –
matrix of mitochondria
= inner mitochondrial membrane
succinate dehydrogenase
citric acid cycle: Pyruvate is oxidized completely to CO2 → – = reducing power
NADH and FADH2
Pyruvate is decarboxylated by – → CO2, NADH and acetyl-CoA
pyruvate dehydrogenase
after pyruvate is decarboxylated, – occur (with additional CO2 release) and NADH, ATP, and FADH2 are generated
oxidative decarboxylation
where does oxidative phosphorylation occur?
inner mitochondrial membrane
– remove H+, pumping these into the intermembrane space,
NADH dehydrogenases
NADH dehydrogenases move electrons to –, a small lipid-soluble electron and proton carrier
ubiquinone
succinate dehydrogenase from the citric acid cycle also transfers electrons to the –
ubiquinone pool
Electrons are then transferred to the cytochrome bc1 complex and to –
cytochrome oxidase
chemiosmotic gradient of H+ in the intermembrane space versus the matrix drives the generation of ATP from ADP by the –
F0F1-ATP synthase,
F0F1-ATP synthase, which is attached to the – side of the inner membrane
matrix
Respiration – with flooding of roots
decreases
ducts in the shoot conducting air to the root
aerenchyma
root outgrowths that protrude out of the water
pneumatophores
Respiration – substantially with temperature
increases
during respiration, free energy is released and transiently stored in – that can readily be utilized for the maintenance and development of the plant
ATP
in functioning plant cell, – carbon is mainly derived from sucrose, trios phosphates and other sugars, lipids, organic acid and sometimes protein
reduced
to prevent incineration of cellular structure by a large release of heat, the cell mobilizes the free energy in sucrose in –
step-by-step reactions
T/F: not all the carbon that enters the respiratory pathways end up as CO2
true
many intermediates are the – for pathways that synthesize nitrogenous compounds, nucleotides, lipids and others
starting points
When oxygen is unavailable, – is the main source of energy
glycolysis
but glycolysis can’t continue if – is not regenerated
NAD+
control of glycolysis is at the level of – and PEP turnover
fructose-6-phosphate phosphorylation
PEP inhibits – the enzyme responsible for the fructose-6-phosphate phosphorylation
phosphofructokinase
glycolysis self-regulates independently of citric acid cycle through a – control
bottom-up
glycolysis is more dominant than pentose phosphate pathways accounting for – of total carbon flux
80-95%
PPP is regulated by the balance of – which impact on the first steps
NADP+ to NADPH
the breakdown of sucrose to pyruvate releases – of the energy in sucrose; the remaining energy is stored in the pyruvate
less than 25%
mitochondria are spherical or rodlike and range from 0.5 to 1 micro meter in diameter and up to – in length
3 micro meter
plant cells typically have – mitochondria than animal cells
fewer
inner membrane contain more than 50% of goal mitochondrial –
protein
aqueous phase within inner membrane
matrix
most ions and charged molecules can diffuse past the – membrane
outer
T/F: mitochondria can carry out protein synthesis
true
mitochondria proliferate through division o=by – of preexisting mitochondria
fission
electrochemical proton gradient also plays a role in the movement of – of the citric acid cycle and – out of the mitochondria
organic acids; ATP
– in the inter membrane space allows ATP 4- to be exchanged for ADP 3- via the ADP/ATP transporter
high positive charge
– are transported in and out of the matrix to the intermembrane space in association with transport of OH- and Pi 2- to the inter membrane space, exchanged with H+ and Pi-
carbon compounds
aerobic respiration yields – ATP per sucrose
60
aerobic respiration captures about – of the free energy available from the complete oxidation not sucrose
52%
key regulators of glycolysis in cytosol, citric acid cycle, and oxidative phosphorylation in mitochondria
ADP and Pi
a buildup of ADP and Pi – respiration
stimulates
plant respiration rates are – on a mass basis than animal tissues because plants have large central vacuole, a bulky cell wall which do not contain mitochondria and thus dilute respiration rate
lower
all tissues respire
24 hrs a day
–of daily gain in photosynthetic carbon can be lost to respiration
30-60%
older trees have – respiration relative to photosynthesis as photosynthetic to non-photsynthetic tissue decreases
higher
T/F: tissues respire at different rates
true
greater overall metabolic activity, – respiration rate
higher
dev buds tend to have – respiration
higher
respiration often declines as tissues and whole plant ages, except –
climerateric
high respiration can increase temp; important for flowers that attract pollinators with heat or smell or for shoots that –
melt their way through snow
respiration will – with O2 availability
increase
lower night-time temp are beneficial for plant growth since at night –
only respiration no photosynthesis
higher night-time temp – overall carbon balance (more respiration and thus less net photosynthesis over the day and night)
reduce
warmer night time temp – tropical tree growth and can halt the growth of mosses which conduct little daily photosynthesis
slow
increased respiration due to – may carry the threat of CO2 accumulation in the atmosphere due to increased plant respiration
global warming
in some tree seedlings, high night time temp may – growth possibly by increasing cell division
increase
recent experimental warming work showed that as plants – to warmer temp during growth, respiration returns to its typical level
acclimate
respiration response of ecosystems to global warming – growth
slow
respiration response of ecosystems to global warming mortality and – CO2 emissions
higher
respiration response of ecosystems to global warming depends on how long the plants have to acclimate and how – temp rise
quickly
