Biochemistry 2280A Study Guide - Midterm Guide: Citric Acid Cycle, Acetyl-Coa, Extrachromosomal Dna
30 Apr 2018
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Biochemistry 2280 – Midterm
Citric Acid Cycle
Identify the different metabolic fates of pyruvate, and how these pathways are related
- aerobic conditions; acetyl CoA
- anaerobic conditions; lactate (vertebrates) or ethanol (microorganisms) — previous topic
- or back to glucose-6-phosphate through gluconeogenesis
Describe the structure of the mitochondrion
Outer membrane
• small pores that allow small molecules to cross
• lipid bilayer
• aqueous channels (pretty big)
Inner membrane
• prevents ions and polar molecules form crossing unless a special
pathway exists
• folded to form cristae (increase surface area substantially)
• much more restrictive as to what can cross it — no pores
Matrix
• the space on the inside enclosed by the inner membrane
• contains extrachromosomal DNA (37 genes and some RNA)
State the net reactions for the conversion of pyruvate to acetyl-CoA and CO2
- this reaction is the boundary point in the cell (between carbohydrate and
fatty acid chemistry) — can’t go back to carb. chemistry
State the net reaction for the citric acid cycle (including stoichiometries)
- NADH and CO2 are released early on, and after that it’s just a regeneration
of oxaloacetate so that we can accept acetyl-CoA again
- there are three irreversible steps, which means it can’t go backwards
- citric acid cycle is dependent on the ETC, and that needs oxygen
- (don’t remember the intermediates, but look at where the energy
comes from)
- IN TOTAL: 4 NADH, 1 FADH2, and 1 GTP (equivalent to 1 ATP)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Identify the different metabolic fates of pyruvate, and how these pathways are related. Anaerobic conditions; lactate (vertebrates) or ethanol (microorganisms) previous topic. Outer membrane: small pores that allow small molecules to cross, lipid bilayer, aqueous channels (pretty big) Inner membrane: prevents ions and polar molecules form crossing unless a special pathway exists, folded to form cristae (increase surface area substantially, much more restrictive as to what can cross it no pores. Matrix: the space on the inside enclosed by the inner membrane, contains extrachromosomal dna (37 genes and some rna) State the net reactions for the conversion of pyruvate to acetyl-coa and co2. This reaction is the boundary point in the cell (between carbohydrate and fatty acid chemistry) can"t go back to carb. chemistry. State the net reaction for the citric acid cycle (including stoichiometries) Nadh and co2 are released early on, and after that it"s just a regeneration of oxaloacetate so that we can accept acetyl-coa again.
