Cycle 5: Integrated Metabolism Flashcards
(25 cards)
How are mitochondria isolated from chlamy cells?
- grind liters of chlamy cells
- purify intact mito
- wash mito
- incubate mito in butter )so that mito don’t shrink or grow)
** measure O2 to see respiration level
Change in respiration rate (oxygen consumption) in isolated mitochondria by addition of NADH?
NADH drives electron transport in OxPhos of CR
- oxygen is consumed in OxPhos to produce water
Change in respiration rate (oxygen consumption) in isolated mitochondria by addition of ADP + Pi?
- ATP availability = ETC increases which consumes O2
Change in respiration rate (oxygen consumption) in isolated mitochondria by addition of uncoupler?
uncoupler doesn’t allow for chemiosmosis so it causes the fasters rate of ETC so highest O2 consumption rate
What is respiration control mechanisms?
availability of ADP and Pi controls rate of ETC and O2 consumption
What is the link between chloroplast and CR?
G3P made in Calvin cycle, leaves chloroplast, makes pyruvate in cytosol
What are the two roles of G3P that is exported form the chloroplast into the cytosol?
energy source - Calvin cycle and carbon source - pyruvate oxidation.
Can Chlamy grow in the dark?
Yes – heterotrophic growth with acetate channel bc it allows acetyl CoA in for Citric acid cycle
Why acetate and not glucose for Chlamy?
no glucose transporter bc glucose not abundant
What is mixotrophic metabolism?
acetate and light = heterotrophic and autotrophic growth - fastest growth rate
TAP has acetate!
How to measure photosynthesis using gas exchange?
CO2 analyzer detect reduction of CO2 because CO2 fixation occurs
What are units of carbon fixation?
mol CO2 considered/min/cell
What is the light response curve shape? What are the two distinct shapes? Why?
CO2 fixation(photosynthesis) vs light intensity/wavelength
Linear portion (light-limited region)
– more ADP and NADPH available so Calvin cycle turns faster since CO2 fixation is dependent on light reactions
Plateau (light-saturated region)
- Calvin cycle has speed limit
Determine the rate of cellular respiration?
y -int (negative CO2 fixation)
What is the Light Compensation Point?
light intensity needed for the rate of photosynthesis = rate of CR
0 net CO2 fixation
carbon gain = carbon loss
What is the shape of the Rate of Reaction vs Enzyme concentration curve?
linear, directly proportional
Why is one adaptation to low temperature is to increase enzyme concentration?
hexokinase works slowly at low temp so increase number of enzyme produced
What is the shape of the Rate of Reaction vs Substrate Concentration curve?
exponential and plateau
plateau because there is a max enzyme catalysis rate no mater how much substrate
What is Vmax? What is Km?
maximum reaction rate (at the plateau)
affinity between enzyme and substrate
(stringer affinity = faster reaction rate = reaches Vmax faster)
What is a competitive inhibitor?
competes with substrate to bind with enzyme active site bc it has the same shape as substrate
can be overcome by high substrate concentration
What does competitive inhibitor do to Km, Vmax? Why?
slower to get to Vmax
lower Km
need more substrate to get to max reaction rate and increase affinity
What type of inhibition is competitive?
reversible (unlike penicillin)
What does rate of reaction vs substrate conc curve look like with competitive inhibitor? without competitive inhibitor?
without - reaches plateau faster
What is Non-competitive (allosteric) regulation of enzyme activity?
inhibitor (dec Km)or activator (inc Km) binds elsewhere on enzyme to induce or repress reaction rate
called allosteric site
