Bacteria can carry out gluconeogenesis using components of the citric acid cycle or amino acids, but...

Bacteria can carry out gluconeogenesis using components of the citric acid cycle or amino acids, but unlike mammals, they can generate glucose from acetate via the glyoxylate pathway. Because bacteria have no organelles, the enzymes of the citric acid cycle and the glyoxylate pathway are not compartmentalized. (a) Why is regulation of the glyoxylate pathway necessary in bacteria? (b) Studies show that bacterial isocitrate lyase is allosterically inhibited by high concentrations of phosphoenolpyruvate. Would you expect to see the inhibition of isocitrate lyase when bacteria are utilizing glucose as a sole carbon source? Why? (c) Would you expect the glyoxylate pathway to be more active than the citric acid cycle when bacteria are growing on acetate? Why? (d) Would you expect to find glucose-6-phosphatase in bacteria?

Expert Solution

Vertebrates cannot convert the acetate to carbohydrates. Conversion of PEP to pyruvate and of pyruvate to acetyl coA are so exergonic as to be essentially irreversible. Moreover, vertebrates lack isocitrate lyase and malate synthase (glyoxylate cycle specific enzymes).

gladiator answered 3 months ago

What role does the citric acid cycle play in amino acid metabolism?

What role does the citric acid cycle play in amino acid metabolism?a. breakdown of glucogenic amino acids feeds metabolites into the citric acid cycleb. amino acid synthesis often relies on intermediates of the citric acid cyclec. breakdown of ketogenic amino acids feeds metabolites into the citric acid cyclea, b, & ca & b

Glycolysis (and its sister pathway gluconeogenesis) and the citric acid cycle are often referred to as...

Glycolysis (and its sister pathway gluconeogenesis) and the citric acid cycle are often referred to as the Central metabolic Pathways. Identify at least 3 other metabolic in aerobic organisms (animal and or plant) that interact with these two central pathways. Briefly describe the connections and conditions that govern the flow of energy and shared intermediates

inThe citric acid cycle there are three reactions of the citric acid cycle it's self that...

inThe citric acid cycle there are three reactions of the citric acid cycle it's self that are regulated: -citrate synthase which is where ATP inhibits in in citeo -isocitrate dehydrogenase: alosterrically activated by Ca2+ and ADP also is inhibited by NADH - alpha ketoglutarate dehydrogenase which is where Ca2+ increases the rate of formation of succinyl-CoA what would happen if all three of these reactions were not present? what would happen if citrate synthase was not functioning, what would happen...

What is an amino acid? How many amino acids are there?

Which of these is NOT a product of the citric acid cycle?

Which of these is NOT a product of the citric acid cycle? CO2 FADH2 NADH + H+ acetyl CoA ATP

Which of these enters the citric acid cycle?

Which of these enters the citric acid cycle? G3P glucose NADH + H+ acetyl CoA pyruvate

To enhance gluconeogenesis using acetyl CoA from the oxidation of fatty acids, the normal TCA cycle...

To enhance gluconeogenesis using acetyl CoA from the oxidation of fatty acids, the normal TCA cycle is turned off by phosphorylation of ___ and the glyoxylate cycle is turned on, instead. This cycle uses two acetyl-CoA to produce one ___ , which is also substrate for gluconeogenesis. Select one: a. isocitrate dehydrogenase ; oxaloacetate b. isocitrate lyase ; citrate c. isocitrate dehydrogenase ; citrate d. isocitrate lyase ; oxaloacetate e. None of these

Amino acids are the building blocks of proteins, and can act as both a Brønsted acid...

Amino acids are the building blocks of proteins, and can act as both a Brønsted acid and a Brønsted base through intramolecular proton transfer (see Chapter 16, pg. 709 of the textbook). The simplest amino acid known is glycine, NH2CH2CO2H (Ka = 4.5 ×10–3 and Kb = 6.0 ×10–5 ), and it can exist in three forms in equilibrium with one another: H2N––CH2––COOH +H3N––CH2––COOH +H3N––CH2––COO– H2N––CH2––COO– Glycine cation zwitterion anion (a) Write the equilibria corresponding to Ka and Kb of...

\Match the following descriptions with the corresponding amino acids: This amino acid is responsible for the...

\Match the following descriptions with the corresponding amino acids: This amino acid is responsible for the strength of rhino horns and wood lignin due to the strong hydrophobic interactions between them. Subtle decreases in the serum pH lead to the protonation of this amino acid, which promotes O2 release from hemoglobin. This amino acid is the nucleophile chymotrypsin uses to attack peptide bonds. This amino acid disrupts α-helices because it makes the nearby protein backbone too flexible (and prevents proper...

What happens during the citric acid cycle?

Question