3.5 Physiology of the GI Tract- Cell Metabolism Flashcards
Metabolism
a set of chemical reactions that are essential for the body to sustain life
Anabolism
the set of reactions in which smaller molecules are combined to make larger, more complex molecules
Catabolism
the set of reactions in which larger molecules are broken down to be used as energy sources for the body
Adenosine triphosphate (ATP)
Most widely used form of energy in the cells
- ATP has energy to donate
Adenosine diphosphate (ADP)
- one less phosphate group than ATP
- ADP can accept energy (phosphate group) to become ATP
Cellular respiration
the process by which cells generate ATP
Aerobic respiration
A function that most organisms carry out that requires oxygen and a fuel (glucose, for example) and releases carbon dioxide, water, and ATP
Carbohydrates
the main source of energy for cells with the body digesting carbohydrates into glucose
Glucose metabolism
- used by the body primarily during high energy demands. As glucose is one of the most abundant biomolecules, the catabolism of glucose is an important metabolic pathway used by microorganisms for ATP production. The complete catabolism of a single molecule of glucose (C6H12O6) yields up to 38 ATP and involves three distinct transitions: glycolysis, cellular respiration, the electron transport chain
Glycolysis
the process of breaking down a 6-carbon molecule of glucose into two 3-carbon molecules of pyruvate. This process yields 2 molecules of ATP per molecule of glucose
Cellular respiration
an aerobic process (oxygen must be present) used by cells to produce energy
Tricarboxylic acid (TCA cycle)
The central pathway of respiration is called the tricarboxylic acid (TCA) cycle, also known as the Krebs Cycle or the citric acid cycle. In the TCA cycle, the pyruvic acid (product of glycolysis) is converted to carbon dioxide forming some additional ATP. At its conclusion, the TCA cycle produces 2 ATP in total (one for each pyruvate processed) and an abundance of electron carriers, known as NADH and FADH2. The production of these electron carriers is the primary function of the TCA cycle, as the transfer of these electrons will fuel the generation of ATP via the electron transport system.
Mitochondria
Respiration takes places in and around this double sided organelle
Fermentation
Takes place in the absence of oxygen
Electron transport chain
continuation of cellular respiration