Cellular Respiration and Fermentation: Chp 9 Flashcards
catabolic pathways
occur when molecules are broken down and their energy is released.
fermentation
the partial degredation of sugars that occurs without the use of oxygen. an expansion of glycolysis in which ATP is generated by substrate-level phosphorylation
cellular respiration
the most prevalent and efficient catabolic pathway. als temer aerobic respiration as oxygenis required along with organic fuel
the primary nutrient molecule that is used in cellular respiration
glucose
oxidation-reduction
the reactions of cellular respiration. electrons are transferred from one reactant to another
oxidation
the loss of one or more electrons from a reaction
reduction
the gain of one or more electrons
glycolysis
occurs in the cytosol. the degradation of glucose of glucose begins as it is broken down into two pyruvate molecules. the six carbon glucose molecules splits into two three carbon sugars.two ATP molecules are consumed, which helps to destabilize glucose and makes it more reactive. Later, 4 ATPs are produced causing a net gain of 2 ATPs. Two NADH are also produced, which will be utilized in the ETC
what is oxidized after glycolysis
pyruvate is oxidized to acetyl CoA. this occurs by a transport protein moving pyruvate from the cytosol into the matrix of the mitochondria. In the matrix, an enzyme complex removes CO2, strips away electrons to convert NAD+ to NADH and adds coenzyme A to form acetyle CoA. Two acetyl CoA are produced per glucose. Acetyl CoA now enter s the enzymatic pathway termed the citric acid cycle
citric acid cycle
occurs in the mitochondrial matrix. the job of breaking down glucose is completed with CO2 realeased as a waste product. Each turn of the citric acid cycle requiresthe input of one acetyl CoA. It requires two turns before glucose is completely oxidized. Each turn produces 2CO2, 3NADH, 1FADH2, and 1ATP; therefore, the final product is 2 pyruvates, 4CO2, 6NADH, 2FADH2, and 2ATP
electron transport chain
is embedded in the inner membrane of the mitochondria. Composed of three transmembrane proteins that work as hydrogen pumps and two carrier molecules that transport electrons between hydrogen pumps. Powered by electrons from the electron carrier molecules NADH and FADH2. As the electrons flow through the chain, the loss of energy by the electrons is used to power the pumping of protons across the inner membrane and at the end of the chain the electrons combine with two hydrogen ions and oxygen to form water. O2 is the final acceptor. the hydrogen ions flow back down their gradient through a channel in the transmembrane protein known as ATP synthase. Chemiosmosis also occurs. The ATP yield per glucose is 30 to 32 ATP
ATP synthase
harnesses the proton-motive force (the gradient of hydrogen ions) to phosphorylate ADP, forming ATP
chemiosmosis
an energy-coupling mechanism that uses energy stored in the form of an H+ gradient across a membrane to drive cellular work. The electron transport chain and chemiosmosis compose oxidative phosphorylation.
anaerobic respiration
by certain prokaryotes generates ATP without oxygen using an electron transport chain
alcohol fermentation
pyruvate is converted to ethanol, releasing CO2 and oxidizing NADH in the process to create more NAD+
