Exam 1 Flashcards
Nucleus
Contains genes that regulates protein synthesis within the cell
Cell membrane
Protective barrier between interior of cell and extracellular fluid
Cytoplasm
Fluid portion of cell that contains organelles (mitochondria)
Hydrolysis
Breakdown
Synthesis
Construction
Metabolism
The sum of all chemical reactions occurring in the body
Anabolic reactions
Synthesis of molecules (including tissues)
Building
Catabolic reactions
Hydrolysis of molecules to release energy
Breakdown
Bioenergetics
- catabolic process
- hydrolysis of ATP to release energy for muscular activity
- followed by hydrolysis of other substances (fats, carbs, proteins, and phosphocreatine) to release energy needed to resynthesize ATP
Exergonic reaction
Release energy
Endergonic reaction
Require energy to be added
Coupled reactions
The liberation of energy in an exergonic reaction drives an endergonic reaction
Hydrogen atoms
Contain one electron
A molecule that loses a hydrogen is oxidized because it lost one electron
Enzyme
Protein molecules
Speed up or slow down chemical reaction
Interact with specific substances
-ase
Glycolytic enzymes
In the cytoplasm
Oxidative enzymes
In the mitochondria
Factors that regulate enzyme activity
Temperature
pH
carbon dioxide concentration
Energy in biological systems is measured in?
Calories
How is energy expressed in humans?
Kilocalories
Energy is transferred from food to our cells to be stored as…
ATP
potential energy
Food sources are processed via
Catabolism (hydrolysis)
ATP stands for
Adenosine triphosphate
ATP includes
1 adenine
1 ribose
3 linked phosphates
How is ATP resynthesized
Food sources
Carbs. Fats. Proteins.
non food sources
Phosphocreatine (PCr)
Not an essential nutrient
Carbs
Found in blood and sarcoplasm after digestion
Glycogenesis
Glucose converted to glycogen
Carbs stored as
Glycogen in liver and muscle tissue
Glycogenolysis
Glycogen converted back to glucose
ATP
High-energy compound
The only source of energy use for muscular activity for rest and exercise
Glycogen storage
Mainly in the skeletal muscles and also in the liver
Fats stored as
Triglycerides
Generally less accessible for catabolism because it first has to be reduced to glycerol and fatty acids
Fats
Provides substantial energy at rest and during prolonged low intensity activity
Fats
Bodily stores more fats or carbs
Fats
Free fatty acids
Used to synthesize ATP
4.1 kcal of energy per gram of…?
Carbs and proteins
9.4 kcal of energy per gram of…?
Fat
Efficient
Amount of ATP produced
Power
How fast ATP is produced
How are carbs used
After ingestion it’s hydrolyzed to glucose then taken up by muscles and the liver
The excess is converted to glycogen (glycogenesis)
Glycogen
Can be used as energy source for resynthesizing ATP
Fat storage
Mainly:
Subcutaneous and visceral
But also found:
intramuscular
Not accessible: skeletal and neural
Proteins or amino acids are/are not a major energy source during exercise?
Are not
Produced nitrogenous byproducts
Proteins
Gluconeogenesis
The generation of glucose by fats or proteins
Limited as an energy source by its rate of energy release need for more oxygen
Fat
How can amino acids be used as an energy source?
If it’s converted to glucose (gluconeogenesis)
and possibly fat
Anaerobic pathways for resynthesizing ATP occur where
Occur in cytoplasm or sarcoplasm in muscle
Aerobic pathways for resynthesizing ATP occur where
Mitochondria
Anaerobic pathways do or do not involve oxygen
Do not
Aerobic pathways do or do not require oxygen
Do
Mechanisms for resynthesizing ATP
Phosphagen system
Glycolysis
Oxidative phosphorylation
Phosphagen system How? Where? Aerobic/anaerobic? Energy used for? Speed?
Hydrolysis of phosphocreatine
Postpones energy depletion by quickly reforming ATP from ADP and a phosphate
-phosphate comes from phosphor eating hydrolysis or previous ATP hydrolysis
Only in cytoplasm/sarcoplasm
Anaerobic
Energy used to regenerate ATP
Immediate source of ATP (powerful)
Aerobic catabolism steps
Aerobic glycolysis
Krebs cycle
Electron transport chain (aka oxidative phosphorylation)
Enzyme that regulates the hydrolysis of phosphocreatine
Which system?
Creatine kinase
Phosphagen system
Controls rate of ATP production by negative feedback system
Produces ATP for short bursts of energy
Phosphagen system
Local PCr stores deplete in 30 secs or less
Glycolysis (anaerobic)
Supplies most of the energy needed for ATP resynthesis for intense activities lasting 30-120 seconds
Byproduct of glycolysis
Pyruvic acid
Which is converted to lactic acid in anaerobic conditions
Enzyme that converts Pyruvic acid to lactic acid in muscles
Muscle specific lactate dehydrogenase
Glycolysis produces how much ATP
About 2 moles per 1 mole of glucose
And
About 3 moles per 1 mole of glycogen
Which systems are the major ATP providers during the early minutes of high intensity exercise?
Phosphagen and glycolytic systems
Powerful but not efficient
Oxidative system aerobic or anaerobic?
Aerobic catabolism
Oxidative system produces ATP where?
Mitochondria of cells
Which yields more ATP aerobic or anaerobic systems?
Aerobic
Which is more powerful, aerobic or anaerobic?
Anaerobic
Which is more efficient, aerobic or anaerobic?
Aerobic
Primary method for ATP production in endurance exercises?
Aerobic
Glycolysis occurs where?
Cytoplasm/sarcoplasm
Lipogenesis
The conversion of fat into glucose and then into free fatty acids
Fat: efficiency & power?
Efficient but not powerful
Oxidation-reduction reactions
- always coupled reactions
- O-R reactions in cells often involve the transfer of hydrogen atoms better than free electrons
Oxidation
Removing electrons
Reduction
Addition of an electron
How is Pyruvic acid used in the Krebs cycle during carbohydrate oxidation?
Converted to acetyl CoA (in sarcoplasm)
Then
Transported to mitochondria by myoglobin (carrier molecule) which results in 2 ATP, CO2, and Hydrogen
The CO2 is removed, but the H combines with 2 coenzymes that take it to the ELECTRON TRANSPORT CHAIN
1 mole of glycogen can generate how many moles of ATP?
39
Electron transport chain is a series of a
Oxidation reduction reactions that recombine hydrogen atoms to make ATP and water
How many ATP are produced with 1 mole of glucose in the ETC?
32
How many ATP are produced with 1 mole of glycogen in the ETC?
34
Lipolysis
Breakdown if triglycerides into glycerol and FFAs
Fat oxidation
Requires more oxygen but generates more ATP than carb oxidation
Oxidation of fats AKA
Beta oxidation
Oxidation of fats steps
FFAs travel trough blood to muscle fibers are hydrolyzed into acetic acid and then acetyl CoA
Acetyl CoA enters the Krebs cycle
And then goes the same as glucose oxidation
How can amino acids be used to generate FFAs?
During starvation by gluconeogenesis and then Lipogenesis
Can some proteins be converted to glucose?
Yes through gluconeogenesis
Direct calorimetry
Measures the body’s heat production to find energy expenditure
Indirect calorimetry
Uses respiratory exchange ratio to find energy expenditure
Overall efficiency of aerobic catabolism at rest?
How much is released as heat?
34%
Heat. 66%
Factors affecting BMR
Stress More muscle mass Body surface area Increases with increase body core temp Higher epinephrine and thyroxin BMR decreases with age
Factors responsible for EPOC
Rebuilding reduced ATP
Clearing lactic acid
Replenishing oxygen supplies
Removing CO2
Increased breathing and catabolic rates (bc increased body temp)
Lactate threshold
Point at which blood lactate begins to accumulate
How is lactate threshold expressed as a percentage of VO2 max used
As a gauge of fitness in endurance events
Unfit persons LT
40-50% of the VO2 max
Fit persons LT
70-90% of their VO2 max
Types of fatigue
PCr depletion (30 secs)
Glycogen depletion (45 mins in localized muscles)
Accumulation of lactate and Hydrogen (less than 30 mins)
Neuromuscular fatigue
Exercising gets harder the longer you do it bc…
Glycogen depletion
At what pH does glycolysis stop and exhaustion set it
6.4
Bc lactate and hydrogen ions build up
Factors that determine endurance performance success
High:
VO2 max
Lactate threshold
Mechanical efficiency
High % of slow twitch muscle fibers (hereditary)
Low body fat and body mass
