crassulacean acid metabolism

Examples of crassulacean acid metabolism in the following topics:

• CAM and C4 Photosynthesis

  • Xerophytes, such as cacti and most succulents, also use phosphoenolpyruvate (PEP) carboxylase to capture carbon dioxide in a process called crassulacean acid metabolism (CAM).
  • In contrast to C4 metabolism, which physically separates the CO2 fixation to PEP from the Calvin cycle, CAM temporally separates these two processes.
  • CAM plants store the CO2 mostly in the form of malic acid via carboxylation of phosphoenolpyruvate to oxaloacetate, which is then reduced to malate.
  • Plants that do not use PEP-carboxylase in carbon fixation are called C3 plants because the primary carboxylation reaction, catalyzed by RuBisCO, produces the three-carbon 3-phosphoglyceric acids directly in the Calvin-Benson cycle.
  • Cross section of a CAM (crassulacean acid metabolism) plant, specifically of an agave leaf.

• Connecting Proteins to Glucose Metabolism

  • Metabolic pathways should be thought of as porous; that is, substances enter from other pathways and intermediates leave for other pathways.
  • However, if there are excess amino acids, or if the body is in a state of starvation, some amino acids will be shunted into the pathways of glucose catabolism.
  • The remaining atoms of the amino acid result in a keto acid: a carbon chain with one ketone and one carboxylic acid group.
  • The keto acid can then enter the citric acid cycle.
  • When deaminated, amino acids can enter the pathways of glucose metabolism as pyruvate, acetyl CoA, or several components of the citric acid cycle.

• Pyruvic Acid and Metabolism

  • The Brønsted–Lowry conjugate base, CH3COCOO−, is known as pyruvate, and is a key intersection in several metabolic pathways.
  • It is the output of the anaerobic metabolism of glucose known as glycolysis.
  • These reactions are named after Hans Adolf Krebs, the biochemist awarded the 1953 Nobel Prize for physiology, jointly with Fritz Lipmann, for research into metabolic processes.
  • Pyruvate is a key intersection in the network of metabolic pathways.
  • Therefore, it unites several key metabolic processes.

• Organic Acid Metabolism

  • Microbes can harness energy and carbon derived from organic acids by using a variety of dedicated metabolic enzymes.
  • The most commonly metabolized organic acids are the carboxylic acids, which are organic acids containing at least one carboxyl (-COOH) group.
  • Many types of carboxylic acids can be metabolized by microbes, including:
  • Formate metabolism is important in methylotrophic organisms.
  • Give examples of types of organic acid metabolism that are used by microorganisms for a sole source of energy

• Lipid Metabolism

  • Among these, lipids can be metabolized by microbes for use as a primary energy source.
  • Although not stated explicitly, the "Organic Acid Metabolism" atom in this module introduces the concept of lipid metabolism by describing the process of fatty acid metabolism through β-oxidation.
  • When metabolized, fatty acids yield large quantities of ATP, which is why these molecules are important energy sources.
  • The metabolic process by which fatty acids and their lipidic derivatives are broken down is called β-oxidation.
  • Activation: Before fatty acids can be metabolized, they must be "activated. " This activation step involves the addition of a coenzyme A (CoA) molecule to the end of a long-chain fatty acid, after which the activated fatty acid (fatty acyl-CoA) enters the β-oxidation pathway.

• Disorders of Acid-Base Balance

  • Acid-base imbalances, including metabolic acidosis and alkalosis, can produce severe, even life-threatening medical conditions.
  • Acid–base imbalance is an abnormality of the human body's normal balance of acids and bases that causes the plasma pH to deviate out of normal range (7.35 to 7.45) .
  • In medicine, metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body.
  • Metabolic alkalosis is a metabolic condition in which the pH of tissue is elevated beyond the normal range (7.35-7.45 ).
  • Describe the types of disorders of acid-base balance that can occur

• Chemical Composition of Bone

  • Acid-base imbalances, including metabolic acidosis and alkalosis, can produce severe, even life-threatening medical conditions.
  • Acid-base imbalance is an abnormality of the human body's normal balance of acids and bases that causes the plasma pH to deviate out of normal range (7.35 to 7.45) .
  • In medicine, metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body.
  • Metabolic alkalosis is a metabolic condition in which the pH of tissue is elevated beyond the normal range (7.35 to 7.45).
  • Differentiate among the acid-base disorders: metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis

• Inhibiting Essential Metabolite Synthesis

  • An antimetabolite is a chemical that inhibits the use of a metabolite, a chemical that is part of normal metabolism.
  • An antimetabolite is a chemical that inhibits the use of a metabolite, a chemical that is part of normal metabolism.
  • The second type of antimetabolite antibiotics consist of pyrimidine analogues which mimic the structure of metabolic pyrimidines .
  • The purine analogues are the third type of antimetabolite antibiotics and they mimic the structure of metabolic purines .
  • Purine analogues disrupt nucleic acid production.

• Connecting Lipids to Glucose Metabolism

  • Like sugars and amino acids, the catabolic pathways of lipids are also connected to the glucose catabolism pathways.
  • Thus, synthesis of cholesterol requires an intermediate of glucose metabolism.
  • Triglycerides, a form of long-term energy storage in animals, are made of glycerol and three fatty acids.
  • Animals can make most of the fatty acids they need.
  • Fatty acids are catabolized in a process called beta-oxidation that takes place in the matrix of the mitochondria and converts their fatty acid chains into two carbon units of acetyl groups, while producing NADH and FADH2.

• Acetyl CoA and the Citric Acid Cycle

  • The citric acid cycle is a key component of the metabolic pathway by which all aerobic organisms generate energy.
  • Its central importance to many biochemical pathways suggests that it was one of the earliest established components of cellular metabolism; it may have originated abiogenically.
  • The name of this metabolic pathway is derived from citric acid, a type of tricarboxylic acid that is first consumed and then regenerated by this sequence of reactions to complete the cycle.
  • The citric acid cycle is a key component of the metabolic pathway by which all aerobic organisms generate energy.
  • The product of this reaction, acetyl-CoA, is the starting point for the citric acid cycle.