Citric acid cycle Flashcards
What is the citric acid cycle?
A common path by which all fuel molecules are broken down to carbon dioxide and water
What are the general steps of the citric acid cycle?
1). A 2-carbon molecule is condensed with a 4-carbon molecule to form a 6-carbon molecule (Citrate) 2). The 6-carbon molecule (citrate) is broken down in stages, resulting in the formation of a new molecule of the original 4-carbon compound 3). During this process, 2 molecules of CO2 and one molecule of GTP are formed 4). At the same time 3 molecules of NADH and one molecule of FADH2 are formed - The hydrogen is eventually combined with the molecular O2 (forming water via reduction) in a process coupled to ATP synthesis
Where does the citric acid cycle occur?
All reactions from the breakdown of pyruvate, including all the steps of the citric acid cycle take place in the Matrix of the mitochondria
What is FAD (Flavin Adenine Dinucleotide) formed from?
Vitamin riboflavin (Vitamin B2)
What do riboflavin (Vitamin B2) deficiencies lead to ?
Riboflavin (Vitamin B2) deficiencies cause lesions of the mucous membranes Examples; - Cracked sore lips and corners of mouth - Similar lesions in genital regions - Tongue swollen, tender, magenta
What is the role of FAD?
Electron and proton acceptor
How does the outer membrane of the mitochondria help with the citric acid process?
The outer membrane is permeable to all small electrolytes
Where does the conversion of pyruvate to lactate occur?
Outside the mitochondria in the cytosol
What is the role of Coenzyme A (CoA)?
Coenzyme A (CoA) forms a high energy bond with carboxylic acids such as acetate to form Acetyl CoA It can also regenerate NADH to NAD during anaerobic respiration to keep generating some ATP
What is CoA?
CoA is a nucleotide that contains the vitamin pantothenic acid (Vitamin B5)
Draw the Citric acid cycle
Below
Draw the short hand equations of what occurs during the citric acid cycle and. the reaction of ketoacids being decarboxylated?
Below
What kind of reaction occurs in the citric acid cycle?
The first step is condensation of the acetyl group of Acetyl-CoA with the keto acid oxaloacetate (Just before entering the cycle)
Then a number of degradation steps occur in the citric acid cycle, because the keto acids formed are quite reactive and they can be decarboxylated
What occurs in the respiratory chain ?
Electron transfer
Where about does oxidative phosphorylation occur?
Oxidative phosphorylation takes place on macromolecular assemblies in the inner mitochondrial membrane