Midterm 1 : Chapters 2,3,4,5 Flashcards
___________ fuel sources from which we obtain energy (ATP) and carbohydrate, fat, protein.
Energy Substrates
________ process of converting substrates into energy, and occurs at cellular level
Bioenergetics
_______ chemical reactions in the body
metabolism
energy released from a biological reaction can be calculated from .?
heat produced
What are the main fuels for exercise?
carbohydrates, fats, protein also referred to as carbon, hydrogen, oxygen, and sometimes nitrogen
energy from chemical bonds in food stored in high-energy compound: ?
ATP
all carbohydrate is converted to?
glucose
about _____ carbohydrates is stored in the body?
- 4.1 kcal/g
- 2,500 kcal
Carbohydrate converted to glucose would be the primary ATP substrate for ?
muscles & brain
When you have extra glucose what happens to it?
glucose is stored as glycogen in the liver and muscles
______ can be converted back to glucose when needed to make more ATP.
glycogen
When glycogen stores are limited; rely on dietary _____ to replenish.
carbohydrate
Fat is an efficient substrate with efficient storage with about how much stored in the body?
- 9.4 kcal/g
- +70,000 kcal stored in body
Fat substrate for prolonged, less intense exercise must be broken down from _____ into _______ and _______.
triglyceride; free fatty acids (FFAs); glycerol
Protein used as energy substrate during starvation should have _____ stored in the body and must be converted into glucose via gluconeogenesis.
4.1 kcal/g
Protein can also be converted into ______ via lipogenesis, for energy storage, and for cellular energy substrate.
FFAs
Free energy released at a controlled rate depends on 2 factors:?
- availability of the primary substrate
- enzyme activity
What do enzymes do?
- are protein molecules
- do not start chemical reactions
- facilitate breakdown (catabolism) of substrates
- lower the activation energy form a chemical reaction
T/F ? Enzyme activity affects metabolic rate
True
if there is an increase in enzymes o enzyme activity the there is _____ in product.
an increase
T/F ? ATP stored in small amounts until needed.
True
Phosphorylation can occur ?
in absence or presence of O2.
What are the three ATP synthesis pathways:
- ATP-PCr system (anaerobic metabolism)
- Glycolysis (anaerobic metabolism)
- Oxidative phosphorylation (aerobic metabolism)
ATP-PCr system starts with?
phosphocreatine (PCr)
_____ energy cannot be used for cellular work, but can be used to reassemble ATP.
PCr
_____ replenishes ATP stores during rest.
PCr
Glycolytic system uses ____ process.
anaerobic
pathway starts with ________, ends with _______. there are 10 to 12 enzymatic reactions total and all steps occur in cytoplasm.
glucose-6-phosphate; pyruvic acid
pathways have an enzyme that control overall rate, can create bottleneck at an early stage, activity influenced by NEGATIVE FEEDBACK, and slows overall reaction, prevents runaway reaction would be considered as?
rate-limiting enzyme
What is the most common rate-limiting enzyme?
PFK
What would be the cons of the glycolytic system?
- low ATP yield, inefficient use of substrate
- lack of o2 converts pyruvic acid to lactic acid
- lactic acid impairs glycolysis, muscle contraction
What would be the pros of the glycolytic system?
- allows muscles to contract when o2 limited
- permits shorter term, higher-intensity exercise
T/F ? Oxidative Phosphorylation uses the aerobic process.
True
Oxidative Phosphorylation occurs in the ?
mitochondria
what are the 3 stages of oxidation of carbohydrate cycle?
stage 1: glycolysis
stage 2: Krebs cycle
stage 3: electron transport chain
pyruvic acid -> acetyl-CoA, then enters?
Krebs cycle
NADH and FADH2 molecules carry ____ and ___ to the electron transport chain.
H+; electrons
_________ is a group of protein complexes located in the inner mitochondrial membrane.
electron transport chain
_____ is the final electron acceptor.
oxygen
many chemical compounds are classified as fats such as:
- phospholipids
- cholesterol
- triglycerides
________: major fat energy source. These are stored in adipocytes (fat cells), between muscle fibers, and within muscle fibers.
triglycerides
what is the process of the oxidation of fat?
- broken down to 1 glycerol + 3 FFAs
- Lipolysis, carried out by lipase
- FFA transported by blood
- enters muscle by diffusion
- … yields 3 to 4 times more ATP than glucose … but slower than glucose oxidation
- this process is called beta-oxidation
________: structural building blocks, enzymatic function, energy under some circumstances.
protein
Where did the lactate come from?
during glycolysis, in anaerobic conditions, pyruvic acid takes hydrogen ions to form lactic acid
What are the 3 ways muscles can utilize?
- oxidation
- lactate shuttle
- the cori cycle
Oxidation occurs in cells with ___________.
high mitochondrial density ( mostly in type I fibers)
What is the Cori Cycle?
starts in muscle as glucose then goes through fast glycolysis to lactate then blood lactate to liver back into glucose then out of the liver as blood glucose and back into the muscle as glucose.
Direct Calorimetry: substrate metabolism efficiency has ___ of substrate energy from ATP, and _____ of substrate energy from heat.
40% ; 60%
Heat production ______ with energy production.
increases
What are the pros of the direct calorimetry?
- directly measures heat
- accurate for total body energy expenditure over time
What are the cons of the direct calorimetry?
- expensive, slow to generate results
- cannot detect rapid changes in energy expenditure
- exercise equipment adds extra heat
- not all heat produced leaves the body; some stored
- sweat affects measurements and calculations
Indirect calorimetry is an estimate of?
total body energy expenditure based on O2 used, CO2 produced during oxidative phosphorylation.
Called indirect calorimetry because?
- heat production not directly measured
- estimate of total body energy expenditure
Indirect calorimetry can also estimate the composition of ___ ____
fuel oxidized
CARBOHYDRATE: During the oxidation of a glucose molecule ___ O2 are consumed and ___ CO2 are produced.
6 ; 6
FATS: ___ CO2 are produced for every ___ O2 consumed.
16 ; 23
When hyperventilation occurs there is an increase in _____ elimination.
CO2
______: rate of energy use by body.
metabolic rate
________: rate of energy expenditure at rest.
basal metabolic rate (BMR)
V02 max expressed in “absolute” terms is used by?
absolute volume of O2 used by entire body
V02 max expressed in “relative” terms is used by?
normalized for body weight
__________: point at which blood lactate accumulation increases markedly
lactate threshold
an increase in lactate threshold _____ entrance performance
increases
as athlete become more skilled, use less energy for given pace = ?
more economical
what are the two muscle sorenesses?
- acute muscle soreness
- delayed-onset muscle soreness
acute muscle soreness occurs?
during and immediately after exercise
delayed-onset soreness occurs?
one to two days later
During acute muscle soreness … ?
- tissue edema (plasma fluid into interstitial space)
- disappears within minutes to hours
major cause for DOMS is?
eccentric contractions
Where are the hormone receptors located?
- steroid (lipid soluble): receptors in cytoplasm or nucleus of target cell
- non steroid (not lipid soluble): receptors on membrane of target cell
T/F ? Nervous system is referred to as electrical signals.
True
Steroid hormones come from?
cholesterol
Phospholipid is made up of?
fat cell walls