Respiration Flashcards
(15 cards)
what is respiration
the breakdown of glucose in a series of enzyme-controlled reactions
describe the process of glycolysis
occurs in the cytoplasm in the absence of oxygen. in the energy investment stage, pyruvate and intermediate 1 are phosphorylated and 2 ATP molecules are produced. in the energy gain stage, 2NADP molecules remove hydrogen ions and electrons to form 2NADPH and 4 ATP molecules are produced to form pyruvate.
why is ATP needed in glycolysis
The first phase of glycolysis requires energy, while the second phase completes the conversion to pyruvate and produces ATP and NADH for the cell to use for energy
what is meant by net gain ATP
in the energy investment stage, 2 molecules of ATP are used. in the energy gain stage, 4 ATP molecules are produced, resulting in a net gain of 2 ATP
describe the citric acid cycle
pyruvate is broken down into an acetyl group which combines with coenzyme A to form acetyl coenzyme A. this combines with oxaloacetate to form citrate. carbon is removed and combines with oxygen in the air to produce CO2. dehydrogenase enzymes remove hydrogen ions and high energy electrons which combine with NAD to form NADH2. these high energy electrons are passed on to the electron transport chain. 1 molecule of ATP is produced. These intermediate steps convert citrate back into oxaloacetate which is then able to combine with another acetyl group to form citrate
describe the role of dehydrogenase enzymes and NAD in aerobic respiration
dehydrogenase enzymes remove hydrogen ions and high energy electrons which combine with NAD to form NADH2. these high energy electrons are passed on to the electron transport chain.
state the reaction involved in anaerobic respiration in animals (fermentation)
glucose > pyruvate > lactate (reversible in the presence of O2)
state the reaction involved in anaerobic respiration in plants (fermentation)
glucose > pyruvate > Ethanol + CO2
what happens to the hydrogen ions and electrons that are removed
passed to the electron transport chain
explain the need for hydrogen acceptors
NAD needed to transport hydrogen ions and electrons to ETC. oxygen needed to prevent buildup of hydrogen
describe the conditions and location of fermentation
occurs in the cytoplasm in the absence of oxygen
compare the ATP production in fermentation vs. aerobic respiration
Anaerobic respiration makes a total of 2 ATP. Aerobic respiration can produce up to 38 ATP
state the location of each stage of respiration
glycolysis occurs in the cytoplasm, the citric acid cycle in the matrix of the mitochondria, and the electron transport chain in the inner membrane of the mitochondria
describe the electron transport chain
The electron transport chain is a collection of proteins found on the inner membrane of mitochondria. NADH release the hydrogen ions and electrons into the transport chain. The electrons transfer their energy to the proteins in the membrane which is used to pump hydrogen ions across the inner mitochondrial membrane. The flow of the ions back across the membrane synthesises ATP by a protein called ATP synthase.
Oxygen is the final hydrogen ion and electron acceptor. The oxygen combines with the hydrogen ions and electrons to form water.
describe the role of ATP
ATP can transfer energy by phosphorylating (add a phosphate) other molecules in cellular processes such as DNA replication, active transport, synthetic pathways and muscle contraction.
