Exam 1 Flashcards
Explain why fat metabolism is dependent on carbohydrate metabolism.
Fat metabolism is dependent upon carbohydrate metabolism due the fact that oxaloacetate comes from glycolysis and without sufficient enough carbohydrates the body will not have sufficient
Describe the factors limiting performance in all-out efforts lasting less than 10 s.
- quantity of mitochondria
- quantity of the ATP And PC
anaerobic
does not require oxygen
aerobic
requires oxygen
Identify the high-energy phosphates.
ATP, PC, ADP
What is a motor unit?
A motor unit consists of one motor neuron and all of the muscle fibers it stimulates.
possible sites of fatigue
CNS, glycogen use, use of Acetylcholine, lactate build up,
nociceptor
a sensory neuron that responds to damaging or potentially damaging stimuli by sending “possible threat” signals to the spinal cord and the brain.
three types of skeletal muscle fibers
fast, slow, and intermediate
Type IIx
fast glycolytic fibers,
- Higher myosin ATPase activity than Type I fibres
- Lower capacity for ATP production via oxidative phosphorylation than ‘red’ fibres.
- Sparser capillary network.
- No intracellular myoglobin
type IIa
Fast oxidative fibers, High capacity for ATP production via oxidative phosphorylation, dense capillary network, High levels of intracellular myoglobin.
oxidative phosphorylation
the final series of chemical reactions in the synthesis of ATP. another name for the ETC.
Type I
Low myosin ATPase activity.
High capacity for ATP production.
Very dense capillary network
High levels of intracellular myoglobin
intracellular myoglobin
intracellular oxygen-binding protein. analogous to hemoglobin.
gives muscle it’s “red” appearance.
factors limiting performance in all-out efforts lasting less than 10 s.
ATP and PC
nutrients used as fuels during exercise.
FFA for long duration lower intensity exercise, carbohydrates for short high intensity work.
OBLA
onset of blood lactate accumulation
Lactate Threshold
The point during exercise of increasing intensity at which blood lactate begins to accumulate above resting levels, where lactate clearance is no longer able to keep up with lactate production.
anaerobic threshold
Another name for the lactate threshold
Acetyl-CoA
2-carbon molecule that is formed from the breakdown of protein, fats, and carbohydrates
Activation Energy
Energy required to initiate chemical reactions.
Adenosine Diphosphate
Molecule that combines w/ inorganic phosphate to form ATP
Adenosine Triphosphate
High-energy phosphate that is synthesized and used by cells immediately for muscle contractions.
ATPase
Enzyme capable of breaking down [ATP] to [ADP + Pi + energy]
ATP-PC System
Metabolic pathway involving muscle stores of ATP and the use of phosphocreatine to rephosphorylate ADP. Used:
o at the onset of exercise
o during short-term, high-intensity work
Beta Oxidation
Breakdown of free-fatty acids to form acetyl-CoA
Bioenergetics
Chemical process involved w/ the production of cellular ATP.
Sarcolemma
Semipermeable membrane barrier that separates cell from extracellular environment.
o Functions:
§ Enclose components of cell
§ Regulate passage of various types of substances in & out of the cell
Coupled Reactions
Reactions that are linked, with the liberation of free energy in one reaction being used to drive a 2nd reaction.
Cytoplasm
Fluid portion between nucleus and cell membrane. Contain the enzymes that regulate breakdown of glucose (glycolysis)
Endergonic Reactions
Energy requiring reactions
Energy of Activation
The energy that must be put into the system before the reaction will occur
Enzymes
Proteins that play a role in the regulation of metabolic pathways in cell.
Exergonic Reactions
Reactions that give off energy as a result of chemical processes.
Flavin Adenine Dinucleotide
Electron carrier.
Glucose
Monosaccharide (simple sugar) that is transported via the blood and metabolized by tissues.
Glycogen
A glucose polymer synthesized in cells as stored carbohydrates.
Glycogenolysis
The breakdown of glycogen into glucose
Glycolysis
Metabolic pathway in the cytoplasm of a cell that results in the degradation of glucose into pyruvate or lactate.
Inorganic Phosphate
Stimulator of cell metabolism
o split off, along w/ ADP, from ATP when energy is released
o used w/ ADP to form ATP in the ETC
Isocitrate Dehydrogenase
Rate limiting enzyme in the Krebs cycle that is inhibited by ATP and stimulated by ADP and Pi
Krebs Cycle
Metabolic pathway in mitochondria in which energy is transferred from carbs, fats, and amino acids to NAD for subsequent production of ATP in the ETC
Lactate
3-carbon molecule that is a potential end-product of glucose metabolism. created when there are not enough O2 to convert glucose into pyruvate.
Metabolism
Total of all cellular reactions that result in the synthesis of molecules for both anabolic and catabolic reactions.
Mitochondrion
Powerhouse of cell. Involved in the oxidative conversion of foodstuffs into usable energy.
Molecular Biology
Branch of bio-chemistry involved w/ the study of gene structure and function.
Nicotinamide Adenine Dinucleotide (NAD+)
Coenzyme that that transfers hydrogen and the energy associated w/ hydrogens.
o Transfers energy from substrates to the ETC.
o Derived from Vitamin niacin (B3)
Organic
Compounds that contain carbon
Oxidation
Removing an electron from an atom or molecule.
Oxidative Phosphorylation
Mitochondrial process in which inorganic phosphate (Pi) is coupled w/ ADP as energy is transferred along the ETC in which oxygen is the final electron acceptor.
Phosphocreatine (PC
Compound found in skeletal muscle and used to resynthesize ATP from ADP.
Phosphofructokinase (PFK)
Rate-limiting enzyme in glycolysis that is responsive to ADP, Pi, and ATP levels in the cytoplasm of a cell.
Reduction
the addition of an electron to an atom or molecule.
G3P
glyceraldehyde 3-phosphate
what are the factors affecting maximal performance?
Diet CNS Function Strength/Skill Environment Energy Production
Diet as factor affecting performance
carbohydrate availability and water intake.
CNS as factor affecting performance
Arousal motivation
Strength/Skill as factor affecting performance
Practice. Natural endowment, body type muscle fiber type.
environment as factor affecting performance
altitude heat humidity
energy production as a factor affecting performance
Anaerobic: PC, Glycolysis
aerobic: VO2 max; Cardiac output; O2 delivery, hemoglobin PO2; O2 extraction; mitochondria.
Discuss the possible sites for fatigue.
Psyche/Brain Spinal Cord Peripheral Nerve Muscle Sarcolemma Transverse Tubular System Ca++ release Actin-Myosin Interaction Cross-Bridge Tension + Heat Force/Power Output
transverse tubular system
T-TUBULES conduct impulses to the Sarcoplasmic reticulum which then stimulates the sarcoplasmic reticulum to release Ca ions to stimulate muscle twitch
Provide evidence for the central nervous system being a site of fatigue.
- CNS arousal facilitate motor unit recruitment to increase strength and alter the state of fatigue.
- Use of neurotransmitters for a prolonged time can reduce the stores of them so a decrease in them leads to a decrease in motor unit work and the ability to stimulate the maximum number of motor units.
sarcolemma
a specialized cell membrane which surrounds striated muscle fiber cells (skeletal Muscle).
Identify potential neural factors in the periphery that might be linked to fatigue.
- T-Tubules
- Inability of Sarcolemma to maintain Na+ and K+ during repeated stimulation. Which creates a decrease in the contractility of the muscle.
- Repeated stim. = ↓ Action Potential frequency to protect muscle from fatigue. Shifts optimal freq. to preserve force output.
Describe the factors limiting performance in all-out efforts lasting less than 10 s.
- Anaerobic sources of energy, PC+ATP
- recruitment of appropriate type II fibers to gen. the force needed.
- Motivation, arousal, and skill to direct the force needed
Describe the factors limiting performance in all-out efforts lasting 10 to 180 s.
Depending on the type of the muscle used:
-Glycolysis and PC (40-90% ATP)
- VO2 (10-60% of ATP)
Not depending on the type of muscle used:
-Muscle and blood pH
factors affecting optimal performance from 3-20 min.
- Cardiovascular system
- HR/SV max, Arterial Oxygen Content (CaO2) ← Arterial Hemoglobin [Hb], Fraction of inspired oxygen (FIO2), and Pressure of oxygen (PO2)
- Mitochondrial content of muscles
- Type I & II fibers recruited
- High altitude/anemia
factors affecting optimal performance from 20 to 60 mins
Heat
Humidity
Dehydration
VO2(MAX) & movement economy
factors affecting optimal performance from 1-4 hours
Environmental factors play a more important role
Muscle & liver glycogen stores try to keep up w/ rate at which carbs are used
Diet, fluid ingestion, and ability to deal w/ heat & humidity influence final outcome
Describe the role of enzymes as catalysts in cellular chemical reactions.
Regulate the speed of chemical reactions. Measured by the rate at which its substrates are converted into products.
three main types of sugar in the body
Monosaccharides – Fructose and glucose (blood sugar)
Disaccharides – Combined monosaccharides
Polysaccharides – Complex carbs (≥3 monosaccharides) Two most common and make up most the sugar we consume
types of fats used
Fatty acids – Primary type of fat used by muscle cells for energy.
Triglycerides – 3 fatty acid molecules – 1 glycerol (type of alcohol that can be used by liver to synthesize glucose))
Phospholipids – provide the structure of cell membranes.
Steroids – (cholesterol) Needed to synthesize fat based hormones .Synthesized in body and can be consumed in foods.
Proteins
Composed of amino acids (20)
Needed to form various tissues, enzymes, blood proteins.
Essential amino acids – cannot be synthesized in body
