Chapter 2 Flashcards
What is the only macronutrient that can be oxidized anaerobically?
Carbohydrates
ATP stores
80-100g at one time, some ATP is always necessary for cellualr functions so it cannot be depleted. During muscle fatigue ATP may only be able to decrease 50-60%
Individuals with more type 2 of type 1 fibers can replinish ATP faster?
type 2.
Myokinase Reaction
aka Adenylate Kinase. 2ADP is changed to ATP + AMP with the enzyme adenylate kinase
Law of mass action/mass action effect
Concentrations of reactants or products in a solution will drive the direction of the reactions. Example: as ATP is hydrolized to create energy there is an increase in ADP and Pi. This will increase the rate of creatine kinase and adenylate kinase reactions until intensity is low enough to avoid depleting CP stores.
Glycolysis
breakdown of carbohydrates (glycogen stored in the muscle or glucose in the blood) to re-synthesize ATP. The end result is pyruvate and it can go in 2 directions. The pyruvate can be converted to lactate or the pyruvate can be shuttled into the mitochondria.
Anaerobic Glycolysis (fast glycolysis)
Converting pyruvate to lactate which causes ATP resynthesis to occur at a faster rate but is limited in duration.
Aerobic Glycolysis (slow glycolysis)
When pyruvate shuttled into the mitochondria to the Krebs Cycle ATP resynthesis occurs at a slower rate but can occur for a longer duration.
What are the 3 ways that lactate can be cleared?
- by oxidation within the muscle fiber where it was produced.
- can be transported in the blood to other muscle fibers
- transported in the blood to the liver where it’s converted to glucose. (cori cycle)
Lactate clearnce rates
lactate concentrations normally return to a pre-exercise value an hour after activity. light activity during the post-exercise period can increase lactate clearnce rates.
Peak blood lactate concentration
occurs approximately 5 minutes after exericse
What happens to pyruvate if there is enough oxygen in the mitochondria
The pyruvate is transported to the mitochondira. NADH is also transported to the mitochondria. When pyruvate enters the mitochondria it is converted to a Acetyl CoA. This Acetyl CoA enters the Krebs cycle for further ATP resynthesis. NADH enters the electronic transport chain where they are used to re-synthesize ATP
Phosphagen System
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 90-100%
- 5-10 seconds
- 1:12 to 1:20
Fast Glycolysis System
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 75-90%
- 15-30 seconds
- 1:3 to 1:5
Fast Glycolysis and Oxidative
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 30-75%
- 1-3 minutes
- 1:3 to 1:4
Oxidative
- Percent of Maximum Power
- Typical exercise time
- range of work to rest period ratios
- 20-30%
- > 3 minutes
- 1:1 to 1:3
Two primary mechanisms for re-synthesizing ATP
- Substrate level phosporylation - direct synthesis of ATP from ADP during a single reaction
- Oxidative phosphorylation - resynthesis of ATP in the electron transport chain
phosphorylation def
adding inorganic phosphate to another molecule. (So like when you have ADP + P = ATP. This is the phosphorylation of ADP to ATP
How is glycolysis stimulated?
high concetnrations of ATP, Pi, ammonia and by a slight decrease in pH and AMP
How is glycolysis inhibited?
by lower pH, ATP, CP, citrate, and free fatty acids
Allosteric inhibition
when an end product binds to regulatory enzyme and decreases turnover rate and slows product formation
Allosteric activation
when and “activator” combines with the enzyme and increases the turnover rate
Lactate Threshold definition
1. when does it begin
the exercise intensity or relative intensity where the blood lactate begins an abrupt increase above the baseline concentration
1. lacate threshold typically begins at 50% to 50% of maximal oxygen uptake in untrained individuals and 70% to 80% in trained athletes.
Onset of blood lactaet accumulation
a second increase in the rate of lactate accumulation which occurs when the concentration of blood lactate reaches 4 mmol/L
Oxidate system
is the primary source of ATP at rest and during low intensity activity, and uses primarily carbohydrate and fat as substrates.
Where is ATP from at rest?
70% is derived from fats and the other 30% is from carbohyrates.
Where is ATP from during high-intensity aerobic exercise?
almost 100% is from carbohydrates.
For each molecule of gluecose that enters the krebs cycle, how many ATP molecules are produced indirectly via substrate level phosphorylation?
- What else is produced?
- How many ATP do NADH and FADH produce?
- Overall the oxidative system, beginning with glycolysis produces?
2
- six molecules of NADH and two molecules of FADH2 are produced which enter the electron trasport chain.
- NADH - 3 and FADH - 2
- 38 ATP from 1 molecule of blood glucose.
Protein Oxidation
proteins are broken down into amino acids. The amino acids are then converted into glucose through gluconeogenesis. The amino acids could also be converted to pyruvate or krebs cycle intermediates to produce ATP.
Wast products of protein oxidation
urea and ammonia
How many grams of glycogen are stored in muscle?
300 to 400 g. Training like sprinting, resistance training, and endurance training can increase resting muscle glycogen concentration. Liver glycogen is more important during low intensity exercise, muscle glycogen is more important during moderate and high-intensity exercise
How many grams of glycogen are stored in liver?
70 to 100 g
What is the limiting factor during resistance exercise that has few sets and few repetitions?
Phosphagens
What is the limiting factor during resistance training with many sets and more total amount work?
muscle glycogen
Optimal carbohydrate ingestion after exercise?
0.7 to 3.0 g of carbs per kilogram body weight is ingested every two hours following exercise. This level of carb consumption can refill glycogen stores at 5 to 6 mmol/g of wet muscle mass per hour during the first 4 to 6 hours after exercise. Muscle glycogen may be completely replenished within 24 hours if enough carbohydrates are ingested, if the exercise has an eccentric component more time may be required to refill muscle glycogen stores.
muscle cell
multinucleated cell in which each nucleus controls a region of the muscle protien (called a nuclear domain)
Steroid Hormone
1. Def
2. what does it bind to?
Explain the whole interaction
- Passively diffuses across the sarcolemma of a muscle fiber. (fat soluble)
It binds with its receptor to form a hormone-receptor complex (H-RC). H-RC
a. The H-RC arrives at the genetic material in the cell’s nucleus and “opens” it in order to expose transcriptional units that coe fro the synthesis of specific proteins
b. RNA polymerase II binds to the promoter that is associated with the specific upstream regulatory elements for H-RC.
c. A polymerase II transcribes the gene by coding for the protein dictated by the steroid hormone.
d. Messenger RNA is processed and moves into the sarcoplasm of the cell, where it is translated into protein
Steroid Migration. Name the 2 ways steroid migrates into the target cell
by either testosterone in skeletal muscle of dihydrotestosterone in sex-inked tissues
Polypeptide Hormone Interaction
Interacts with a receptor via the cytokine-activated JAK/STAT signaling pathway. The hormone binds to an external receptor and a secondary messenger (STAT) is activated that can enter the cell nucleus
Interactions with receptor (hormones) are higher when?
exercise acutely increases the blood concentrations of hormones
Receptors (hormones) are less sensitive when?
- the physiological function to be affected is already close to a genetic maximum
- resting hormone levels are chronically elevated due to disease or exogenous drug use
- mistakes are made in exercise prescriptions.
Examples of the potential types of adaptation in the endocrine system with resistance exercise?
give 6
- Amount of synthesis and storage of hormones
- Transport of hormones via binding proteins
- Time needed for the clearance of hormones through liver and other tissues
- Amount of hormonal degradation that takes place over a given period of time
- How much blood-to-tissue fluid shift occurs with exercise stress
- How many receptors are in the tissue
Primary Anabolic Hormones
- Testosterone
a. the primary androgen hormone that interacts with skeltal muscle tissue
b. effects on muscle tissue: GH responses that lead to protein synthesis, increased strength and size of skeletal muscle, increased force production potential and muscle mass
c. Diurnal variations Men - exercise later in the day is more effective for increaseing overall testosterone concentrations over and entire day. Women - is doesn’t matter.
Testosterone responses in women
women have 15 to 20 fold lower concentrations of testosterone than men do, and if acute increases occur after ressitance training workout, they are small
Growth Hormone
- secreted by and what does it interact with?
- regulated by
- altered by
- secreted by the pituitary gland, interacts directly with target tissues, which include bone, imune cells, skeltal muscle, fat cells, and liver tissue.
- regulated by neuroendocrine feedback mechanisms and mediated by secondary hormones
- GH release patterns altered by age, gender, sleep, nutrition, alcohol consumption, and exercise
Which sex has higher levels of growth hormone?
Women.
Training-related changes in GH
- a reduction in GH response to an absolute exercise stess and alterations in GH pulsatility characteristics.
Insulin - like growth factors
a. role in protein anabolism
b. exercise results in acute increases in blood levels of IGF-1
Cortisol
- def
- Resistanc exercise response of cortisol
- An adrenal hormone. Has catabolic effect, converts amino acids to carbohydrates, increases the elvel of enzymes that break down proteins, and inhibits protein synthesis.
- cortisol increases with resistnace exercise, training may reduce the negative effects of this increase, vast differences are observed in the physiological role of cortisol in acute versus chronic responses.
Catecholamines
Roles
- increase force production via central mechanisms and increasd metabolic enzyme activity
- increas muslce contraction rate
- increase blood pressure
- increase energy availability
- increase blood flow
- augment secretion rates of other hormones, such as testosterone.
Paracrine secretion
interacts with adjacent cells and does not need to enter the bloodstream
Benefits of GH
Decreased glucose consumption Decreased glycogen synthesis Increased efficiency of amino acid deliver yIncreased cartilage growth Increased fatty acid consumption
allosteric binding site
on receptors and allow for substrates other than hormones to bind causing an increase or decrease in cellular response to the primary hormone.
fibrous joint
virtually no movement
cartilanginous joints
limited movement
synovial joints
consideral movement
antaganist
muscle that can slow down or stop the movement, assists in joinst stabalization and braking limb at end of movement
synergist
a muscle that assist indirectly with movement
fulcrum
pivot point of a lever
force
mass + acceleration
work
force x distance
power
work/time or
force x velocity
What kind of power capabilites does a football lineman need?
Slow, pushing against a heavy weight
What kind of power capabilites does a baseball player need?
high speed (just the bat and arm to resist)
most initial strength improvements are
neural adaptiations
When throwing a ball, the agonist muscle is the ______________, the antagoinist muscle is the ____________, and the synergist muscle is ___________
Triceps; Biceps; Scapular Stabilizers
