Respiration and Photosynthesis Flashcards
what happens to sugar (glucose) in cellular respiration
oxidised
where does respiration occur
mitochondria
what are the 2 phases of glycolysis and what do they yield
energy investment phase
- 2 ATP (cleaves 6C sugar)
energy payoff phase
- 4 ATP, 2 Pyruvate, 2 NADH
what is substrate level phosphorylation
production of ATP by an enzyme
substrate(+P) + ADP = product + ATP
what are the 3 metabolic stages that make up respiration
1 - glycolysis
2 - citric acid cycle
3 - oxidative phosphorylation
what do the 3 metabolic stages of respiration each do
1) glycolysis converts glucose -> 2 pyruvate
2) citric acid cycle completes glucose breakdown
3) oxidative phosphorylation uses e- transport chain to drive ATP generation
how do the products of glycolysis move into the mitochondrial matrix (link glycolysis to citric acid cycle)
pyruvate -> acetyl CoA
- 2 carbon acetyl fragment removed from pyruvate
- move through transport protein
- added to Coenzyme A
- forms acetyl CoA
What is the input and output of the citric acid cycle
input = acetyl CoA
output = 3 NADH, 1 GTP, 1 FADH2
(NADH and FADH2 store high energy electrons released)
explain the process of the electron transport chain in respiration
- electrons from NADH, FADH2 lose energy through several steps
- energy drives H+ ions across membrane (matrix -> intermembrane space)
- transmembrane gradient created
- ATP synthase (protein) spins as protons move back down gradient
- turning motion generates ATP
draw a summary diagram of the steps of respiration
Where does photosynthesis take place
chloroplast
what are chlorophyll, and what is their structure
light capturing pigments
head: light absorbed by electrons
tail: hydrophobic, holds chlorophyll in thylakoid membrane
what are the 2 stages of photosynthesis
1) light reactions
2) dark reactions (carbon fixation)
what are the 3 key components of the light reaction stage of photosynthesis
- pigments (chlorophyll)
- photosystems I & II
- e- transport chain
what do photosystems I & II do in photosynthesis (light reactions)
-harvest light energy by antenna complex
- funnel to chlorophyll molecules in reaction centre
- high energy e then from reaction centre to e- transport chain in thylakoid membrane
how is the H+ gradient created in e- transport chain in photosynthesis
- photosystem II splits H2O -> H+
- H+ taken up on other side, strengthening gradient
Why is carbon fixation required in photosynthesis in chloroplasts
inner membranes of chloroplast impermeable to ATP and NADH, so must convert to sugar to export and provide energy to rest of the cell
what is the central reaction in carbon fixation and what enzyme carries this out
inorganic (CO2) -> organic
done by Rubisco (slow)
what is the net input and output of carbon fixation
input: 3 CO2
output: 1 G3P
What are the 3 ways G3P can be used after being generated in carbon fixation
1) retained -> starch (in times of excess photosynthesis)
2) moved into cytosol and into glycolytic pathway (to be used)
3) exported and converted to other metabolites
