Biology Module 6 Flashcards
ATP
Powers nearly every activity that requires energy input
Aerobic respiration
Use of glucose + oxygen to generate ATP, used by plants animals most microbes in O2 rich environments
Anaerobic respiration & fermentation
Generate ATP without using O2
3 main groups of biochemical pathways of respiration
Glycolysis, Krebs cycle, electron transport
Glycolysis
Six-carbon glucose molecule splits into two three-carbon molecules of pyruvate
Two ways glycolysis harvest energy
- Electrons transfer to electron carrier molecule NADH 2. Generates two molecules of ATP
Krebs cycle / Transition step
Oxidize pyruvate, release CO2, enzymes rearrange atoms + bonds to transfer pyruvate’s potential energy to ATP, NADH and FADH2
FADH2
Coenzyme that carries electrons in respiration
Electron Transport Chain
Transfers energy rich electrons from NADH + FADH2 through series of membrane proteins, Energy used to create gradient of hydrogen ions
ATP synthase
Enzyme that forms a channel in the membrane, releasing protons and using potential energy to add phosphate to ADP while spent electrons transfer to O2 generating water as waste product
Euka cell mitochondria
Specialized organelles that house the other reactions of cellular respiration, bounded by outer membrane + highly folded inner membrane
Intermembrane compartment
Area between the two membranes
Cristae
Folds of the inner membranr
Matrix
Fluid enclosed within the inner membrane
Substrate level phosphorylation
An enzyme transfers a phosphate group directly from high energy donor molecule to ADP, doesn’t require photon gradient or ATP synthaze
Transition step
Further oxidizes each pyruvate molecule by first removing a molecule of CO2, reduces NAD+ to NADH, two carbon group acetyl transferred to form coenzyme A
Acetyl coenzyme A
Molecule that enters the Krebs cycle in cellular respiration
Kreb’s cycle
Completes oxidation of each acetyl group, releases CO2, cycle begins when acetyl CoA sheds coenzyme and combines with four molecule oxaloacetale resulting in six-carbon citrate
Electron transport chain
High energy electron carriers (NADH + FADH2) transferred to ETC in inner mitochondrial membrane, first protein in chain accepts electrons from NADH, FADH2 donates electrons to second
Anaerobic respiration
Uses electron acceptor other than O2, always lower ATP yield
Fermentation
Metabolic pathway in which NADH from glycolysis reduces pyruvate, regenerates NAD+to continue glycolysis, produces no additional ATP, common for microorganisms in sugar rich environments
Where does x occur
Euka: krebs in matrix(mito) ETC inner membrane
Proka: krebs in cytosol ETC cell membrane
