3.5.2 Respiration Flashcards
what is the first overall stage of respiration
Draw glycolysis
What is the second stage of respiration?
The link reaction
What are the products of the link reaction?
CO2, Acetyl CoA, and NADH
What are the products of one Krebs cycle?
ATP, 2 CO2, 3 NADH and FADH2
What are the stages of respiration?
Glycolysis, link reaction, Krebs cycle, electron transport chain
Where does glycolysis happen?
Cell cytoplasm
How many times do the Link reaction and Krebs cycle occur for every glucose molecule?
Twice
What happens during glycolysis?
Triose phosphate is oxidised forming 2 pyruvate molecules. 2 NAD molecules are reduced to 2 NADH. 4 ATP are produced but the net gain is 2ATP
What is released from NADH and FADH2 when they are oxidised?
Hydrogen atoms
What is oxidative phosphorylation ?
The process where the energy carried by electrons from NADH and FADH2 is used to make ATP in the electron transport chain
What is the energy released from electrons as they move down their electron transport chain in respiration used for?
Used by electron carriers to pump H+ ions into the intermembrane space
How is ATP made in electron transport chain ?
H+ ions move down the electrochemical gradient back into the mitochondrial matrix via the ATP synthase enzyme. This movement drives the synthesis of ATP
What is the final electron acceptor in respiration ?
O2
What happens to lactate after a period of anaerobic respiration?
Lactate is oxidised back into pyruvate. It is directly oxidised into CO2 and H2O via Krebs Cycle, releasing energy to synthesise ATP. Some lactate is converted to glycogen and stored in muscle or liver cells.
What is aerobic respiration?
splitting of glucose to release CO2 as a waste product and combining H2 with atmospheric O2 with the release of a large amount of energy
Why does the Link reaction occur in the mitochondrial matrix?
the enzymes and coenzymes needed are locate here. NADH made is in the right place to be used by oxidative phosphorylation
How is acetate made from pyruvate ?
Pyruvate is carboxylated as one carbon atom is removed to form CO2 and then NAD is reduced by collecting hydrogen from pyruvate to form acetate
What are the products of anaerobic respiration in plants, animals and yeast?
In plants and yeast - pyruvate + NADH –> ethanol + CO2 + NAD. In animals - pyruvate + NADH –> lactate + NAD
How is NAD regenerated in anaerobic respiration in humans
pyruvate is reduced (and forms lactate), the NADH is oxidised back into NAD
What are the folds in the inner membrane of mitochondria called?
Cristae
What is substrate level phosphorylation and when does it occur
THe production of ATP through a direct chemical reaction. It occurs in the last stage of glycolysis and during the krebs cycle. Overall 4 moleucles of ATP are made via this process in aerobic respiration
describe the structural adaptations of the mitochondria
What are some similarities between the chloroplast and mitochondria
Both have circular and naked DNA. Both have 70s ribosomes and a double membrane. They both contain extensively folded membrane system to provide a large surface area for proteins of their electron transport chains
What is the consequence of uncoupling proteins (or uncoupling chemicals) being added to the mitochondrial inner membrane
Some protons can leak back into the mitchnodrial matrix without going through ATP synthase. This causes a greater proportion of chemical energy in glucose to be released as heat energy.
Define chemiosmosis
The movment of H+ ions down an electrochemical gradient through ATP synthase
Cyanide CN- ions bind to the final protein in the electron transport chain instead of oxygen. What is the consequence
All the proteins in the electron transport chain become reduced and pumping of protons ceases. No ATP can be made by ATP synthesis and the cell will either switch to anaerobic respiration or die.
compare and contrast anaerobic respiration in human cells and yeast cells
