Chapter 3 - Bioenergetics Flashcards
Metabolism
Sum of all chemical reactions that occur in the body.
- anabolic reactions (synthesis of molecules)
- catabolic reactions (breakdown of molecules)
Bioenergetics
converting foodstuffs (fats, proteins, carbohydrates) into energy. (Back up source of energy)
Cell Membrane ( sacrolemma)
semipermeable membrane that separates the cell from the extracellular environment.
Nucleus
contains genes that regulate protein synthesis
Cytoplasm
fluid portion of the cell
Organelles
mitochondria (power house) most of the ATP is made here
Endergonic reactions
chemical reaction that requires energy to be added
Exergonic reactions
chemical reaction that releases energy –> ATP - heat –
Coupled Reactions
chemical reaction that liberates energy in an exergonic reaction to drive an endergonic reaction.
Oxidation
Removing an electron
ex. NADH -> NAD
Reduction
addition of an electron
ex. NAD -> NADH
Oxidation - Reduction Reactions
Oxidation and reduction are always coupled reactions.
- often involves the transfer of hydrogen atoms rather than free electrons. (hydrogen contains one electron)
- a molecule that loses a hydrogen also loses and electron and therefore is oxidized.
Nicotinamide adenine dinucleotide (NAD)
oxidized form NAD+
-reduced form NADH
(plays an important role in transfer of electrons and hydrogen ions in the cell.) also important for ATP synthesis in the mitochondria.
Flavin Adenine Dinucleotide (FAD)
oxidized form FAD
-Reduceed form FADH2
(plays an important role in transfer of electrons and hydrogen ions in the cell.) also important for ATP synthesis in the mitochondria.
Enzymes
Catalysts that regulate the speed of reactions. (lower the energy of activation)
-factors that regulate this activity (temp, substrate concentration, pH, product inhibition, cofactors)
Factors that alter enzyme activity
temperature (small rise in body temp increases enzyme activity; exercise results in increased body temp)
pH (change in pH alters enzyme activity - narrow range; lactic acid produced during exercise)
Carbohydrates
-includes monosaccharides, disaccharides, and polysaccharides.
-glucose breakdown (glycolysis)
-glycogen (multitude of glucose molecules linked)
storage form of glucose in liver and muscle
Fats
Fatty acids have an even number of carbons (e.g. 16) {the primary type of fat used by the muscle}
- Triglycerides (storage from of fat in muscle and adipose tissue)
- Phospholipids (not used as an energy source - in membrane- signals)
- Steroids (derived from cholesterol ; needed to synthesize sex hormones and glucocorticoids.
Protein
Building blocks of our bodies as structural units; however not a a primary energy source during exercise.
- composed of amino acids (about 20)
- some can be converted to glucose in the liver
- others can be converted to metabolic intermediates
- is not a primary energy source during exercise. (usually less than 2% of proper nutrition)
Kinase(s)
adds a phosphate to some molecules.
Bioenergetics
making energy using nutrients; does not involve O2; phosphocreatine breakdown
-Adenylate Kinase Reaction ADP + ADP –> ATP + AMP
Oxidative Physophorylation
making ATP in the presence of O2.
ATP-PC System
immediate source of ATP replenishment
- PC + ADP –> ATP + C
- depletion of PC may limit short term, high intensity exercise.
Lactic Acid
produced in glycolysis. (rapid dissociation to lactate and H+)
Krebs Cycle
apart of the aerobic ATP production (into mitochondria)
- Pyruvic acid (3C) is 1st converted to acetyl-CoA (2C)
- Acetyl CoA combines with oxaloacetate (4C) to form citrate (5C)
- Citrate is metabolized to oxalocetate.
- Produces 3 NADH’s and 1 FADH2 –> electron transport chain
Aerobic ATP production
making ATP in the presence of O2.
-oxidative phosphorylation occurs in the mitochondira
Rate limiting enzymes
an enzyme that regulates the rate of a metabolic pathway
Modulators of rate limiting enzymes
levels of ATP and ADP+Pi
(high levels of ATP inhibit ATP production.)
(low levels of of ATP and high levels of ADP + Pi stimulates ATP production).
Calcium
what may stimulate aerobic ATP production ?
What macronutrient is in limited supply?
Carbohydrate
What macronutrient is in abundant supply?
Lipids (Fats)
What is the storage form of fat in muscle and adipose tissue; and also breaks down into glycerol and fatty acids (3) via lipolysis
Triglycerides
What form of fat that is not used as an energy source and is located in cell membranes (signals)?
Phospholipids
What form of fat is derived from cholesterol and is needed to synthesize sex hormones and glucocorticoids.?
Steroids
What is the process of protein being converted into glucose (in the liver) when there aren’t enough carbohydrates?
Gluconeogenesis
In what form is glucose stored in animal cells
Glycogen
What is the primary form of fat used as an energy source in cells; and stored as triglycerides in muscle and fat cells?
Fatty Acids
High energy phosphate that consists of adenine, ribose, and three linked phosphates.
Adenosine Triphosphate (ATP) -synthesis ADP + Pi -> ATP
_______ breakdown helps to resynthesize ATP immediately.
Phosphocreatine
What is the oxidative formation of ATP called? (uses glycogen, glucose and fatty acids (and in this order)).
Aerobic pathways
What is the process of breaking down triglycerides into fatty acids and glycerol known as?
Lipolysis
The process of lipolysis is regulated by what?
Lipase
What is the pathway called that creates ATP without the use/need of O2 but by either phosphocreatine breakdown and/or degradation of glucose (glycolysis) ?
Anaerobic Pathway
The simplest and most rapid method of producing ATP involves what?
The donation of a phosphate group and its bond energy from Phosphocreatine to ADP to from ATP.
the breakdown of phosphocreatine in order to form ATP is catalyzed by what enzyme?
Creatine Kinase
What are anabolic reactions?
synthesis of molecules
what are catabolic reactions?
breakdown of molecules
