Theme 2 - Part B Flashcards
What ancient pathway is part of aerobic respiration, fermentation AND anaerobic respiration? Where in the cell does it occur?
Glycolysis; in the cytosol
What is the net ATP production in glycolysis?
2 ATP (2 initially invested, 4 produced)
At the conclusion of glycolysis, in what molecule(s) is most of the energy from glucose contained?
pyruvate
Describe the process of substrate-level phosphorylation. In which steps of cellular respiration does it occur?
phosphate group from a high-energy substrate molecule is transferred to ADP, producing ATP. This process is mediated by an enzyme.
Occurs in glycolysis and the citric acid (Krebs) cycle.
What is the effect of a competitive and non-competitive inhibitor on enzyme kinetics (Km and Vmax)?
competitive: increased Km; Vmax is unchanged.
non-competitive: decreased Vmax; Km is unchanged.
Through what type of transport is pyruvate transported from the cytosol to the inter-membrane space? From there to the matrix?
Transported through facilitated diffusion to the inter-membrane space;
transported through secondary active transport to the matrix
In which steps of cellular respiration is carbon dioxide produced?
Pyruvate oxidation and citric acid cycle
What are the products of one turn of the citric acid cycle?
2CO2; 3NADH; FADH2; ATP
The electron transport chain consists of 4 protein complexes; which is a single peripheral membrane protein?
Complex II
Electron flow from one complex to the next is facilitated by two mobile electron shuttles; which ones?
Ubiquinone: hydrophobic molecule found in core of membrane; shuttles e- from complexes I and II to complex III.
Cytochrome c: located in the inter-membrane space side of membrane; shuttles e- from complex III to complex IV.
What are prosthetic groups, and what role do they play in the electron transport chain?
The are redox-reactive cofactors that alternate between reduced and oxidized states, accepting e- from upstream molecules and donating e- downstream.
They are arranged from high to low free energy (and increasing affinity for e-), allowing sequential and spontaneous e- movement down the ETC.
Which components of the ETC pump protons into the inter-membrane space?
Complex I, Ubiquinone and Complex IV
What is the final electron acceptor in aerobic respiration?
O2
What is proton-motive force?
The combination of H+ concentration gradient and voltage difference across the membrane produces stored energy known as PMF
What is the process of harnessing PMF to do work referred to?
chemiosmosis
