Chapter 25 – Flashcards

to obtain energy that can be use to generate ATP. Reactions within mitochondria provide most of he energy needed by a typical cell.

oxygen, nutrients, and organic substrates to carry out metabolic reactions.

refers to all the chemical reactions that occur in an organism.

the intracellular reactions that are essential for energy production for the maintenance of homeostasis.

the break down of organic substrates and release of energy for ATP synthesis. EG. Enzymes break down carbohydrates to glucose, triglycerides to fatty acids and glycerol, and proteins to amino acids

The synthesis of new organic molecules. Synthesis of new organic components careers for four basic reasons : to perform structural maintenance or repairs, to support growth, to produce secretions, to build Reserves nutrients through glycogen in the liver and muscles, proteins in muscles common triglycerides in adipocytes and liver.

Most cells generate ATP and other high energy compounds by breaking down carbohydrates. Carbohydrate breakdown occurs in small steps with energy release that converts ADP to ATP. The complete catabolism of a molecule of glucose provides a cell with 36 ATP. First steps of carbohydrate breakdown occurs in cytosol, and do not require oxygen (anaerobic). Most of the ATP production occurs in the mitochondria and require oxygen (aerobic)

Refers to the process of the breakdown of glucose to pyruvic acid.

At the end of glycolysis , pyruvic acid still holds a high amount of energy. If oxygen supplies are adequate mitochondria absorb pyruvic acid. In mitochondrian, a pyruvic acid molecule is converted into acetyl COA.

The formation of citric acid into acetyl - COA is the first step of a sequence of reactions called the tricarboxylic acid cycle or citric acid cycle or Krebs cycle. The function is to remove hydrogen atoms from organic molecules. A small amount of ATP is produced in this cycle.

is the generation of ATP with mitochondria in a reaction sequence that requires coenzymes and consume oxygen. Over 90% of the ATP used by cells is produced at this stage of catabolism.

For most cells the complete reaction pathway that begins with glucose and ends with carbon dioxide and water is the main method of generating ATP.

Skeletal muscles utilize fatty acids at rest. Cells break down proteins for energy with lipids or carbohydrates are unusable. Nucleic acids are seldom catabolized for energy.

Are some steps in glycolysis are not reversible, glucose cannot be produced by performing glycolysis in reverse.

Synthesis of glucose from noncarbohydrate precursors such as lactic acid common glycerol and amino acids.

The storage from the glucose found in the liver and muscles.

The process of glycogen formation from glucose.

The breakdown of stored glycogen to produce glucose.

Lipid molecules contain carbon, hydrogen, and oxygen. Triglycerides are the most abundant lipid in the body.

The breakdown of lipids into pieces that can be converted into pyruvic acid or channeled directly to the TCA cycle.

A triglyceride is first split into its component parts, glycerol and free fatty acids. Glycerol enters the TCA cycle after enzymes in the cytosol convert to pyruvic acid. Fatty acid molecules are broken down to form acetyl - COA. Cells contain 144 ATP molecules from the breakdown of a 18 carbon fatty acid.

Lipids are important as an energy reserves as they can produce large amounts of ATP. Lips are processed inside mitochondria and mitochondrion activity require oxygen. Lipids cannot provide large amounts of ATP in a short time. at rest, muscle cells break down fatty acids, when active skeletal muscle fibers shift to glucose.

The synthesis of lipids. Can use almost any organic substrate - lipids, amino acids, and carbohydrate.

Amino acids

100,000 to 140,000

20

ATP

Liver cells break down proteins for ATP

10 amino acids the body cannot synthesize, we need to have in our diet

The 10 amino acids that the body can synthesize

Is the focal point of the metabolic regulation. It can break down or synthesize carbohydrates, lipids, and amino acids. It contains significant energy reserves for glycogen and lipids.

stores lipids primarily as triglycerides

Maintain substantial glycogen stores and amino acid reserves in muscle protein

has a high demand for energy, glucose in particular, but does not hold reserves

Are able to metabolize glucose, fatty acids, ect.