Ch. 7 Flashcards
What is the relationship between photosynthesis and cellular respiration?
they are inverse relationships; one removes CO2 from the atmosphere while the other puts it back
What is the balanced equation for photosynthesis?
6CO2 + 6H2O –> C6 H12 O6 + 6O2
What is the balanced equation for cellular respiration?
C6 H12 O6 + 6O2 –> 6CO2 + 6H2O
What is cellular respiration?
a process that releases energy from food in the presence of oxygen
catabolic pathway of aerobic & anaerobic respiration –> makes ATP
What is fermentation?
a catabolic process that makes a limited amount of ATP from glucose without an ETC and prodcues either alcohol or lactic acid
a partial degration of sugars without oxygen
What is aerobic respiration?
a catabolic pathway that uses oxygen as the final electron acceptor in an ETC and ultimately produces ATP
most efficient catabolic pathway
What is an electron transport chain? (ETC)
a sequence of electron carrier molecules that shuttle electrons down a series of reactions that release energy to make ATP
produces most ATP in cellular respiration
found in mitochondria and chloroplasts
What is the downhill route electrons travel during cellular respiration?
glucose –> NADH –> ETC –> O2
What are the 3 stages of cellular respiration?
- glycolysis
- pyruvate oxidation & the Krebs cycle
- oxidative phosphorylation
What is glycolysis?
the splitting of a glucose molecule into 2 pyruvate molecules
STAGE 1
refer to laundry list for products
What is pyruvate oxidation?
pyruvate is oxidized to create acetyal CoA, which is the entry compound for the Krebs cycle
STAGE 2A
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What is the Krebs Cycle?
AKA Citric Acid Cycle
- oxalocetate combines with acetyl CoA to form citrate
- stage where all bonds from food are broken down
STAGE 2B
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What is oxidative phosphorylation?
produces an abundant amount of ATP through the phosphorylation of ADP
STAGE 3
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Why is oxygen required in oxidative phosphorylation?
in order to receive electrons from protein complexes in the membrane
What is the ultimate end of oxygen in oxidative phosphorylation?
it will turn into water by the stage’s end
How are hydrogen ions (protons) moved into the intermembrane space?
as electrons move down the ETC, they pull H+ across the membrane via proton pumps
What does the accumulation of H+ do in the ETC?
causes protons to flow through ATP synthase in the inner membrane –> ATP production
What is ATP synthase?
an enzyme that uses energy from H+ to bind ADP and a phosphate group together to form ATP
What are the pros of anaerobic pathways?
- occurs at a very fast pace
- does not require O2
What are the cons of anaerobic pathways?
- produces very minimal ATP
- produces lactic acid or alcohol
What is the balanced equation for lactic acid fermentation?
C6 H12 O6 –> 2C3 H6 O3
What is the balanced equation for alcohol fermentation?
C6 H12 O6 –> 2C2 H5 OH + 2CO2
Into which stage of cellular respiration can fats and proteins be inserted?
Citric Acid Cycle
What is substrate-level phosphorylation?
when ADP or GDP is phosphorylated by a substrate to produce ATP or GTP
What is chemiosmosis?
the process of diffusion of ions across a selectively permeable membrane
What function do NADH and FADH2 serve in cellular respiration?
act as high electron carriers used to transport electrons made from glycolysis and the Krebs cycle to the ETC
What is pyruvate?
- the end product of glycolysis, made when a glucose molecule is split
- converted to acetyl CoA when oxidized before entering the Krebs cycle
What are downhill reactions?
spontaneous reactions that release energy
What are uphill reactions?
non-spontaneous reactions that absorb more energy
