Physiology of Exercise Exam 1

carbohydrates, lipids, and proteins

what are the three macronutrients

glucogenesis

the synthesis of glycogen from glucose is what?
(glucose-->glycogen)

gluconeogenesis

glucose synthesis largely from structural components of noncarbohydrate nutrients
(protein-->glucose)

glycogenolysis

glucose formation from glycogen
(glycogen-->glucose)

carbohydrate (CHO)

converted to glucose

monosaccharides

one sugar

disaccharides

two sugars

polysaccharides

multiple sugars

glycogen

storage carbohydrate in muscle and liver

2000 kcal

body stores about _____ as carbohydrates

400g

muscle stores about ____ glycogen

90-100g

liver stores about ______ glycogen

15g/kg BW

upper limit for glycogen storage averages about ____

fuel mixture

intensity and duration determine _____

lipids (fats)

provides substantial energy at rest (2/3 of kcal) and during prolonged intense aerobic activities

55%

1 hour of short-distance exercise decrease liver glycogen by _____

fat

what serves as the main energy substrate during low-intensity exercise?

falls, increases

as sub maximal activity progresses in a glycogen depleted state, blood glucose _____ and circulating free fatty acids _____.

Lipolysis

breakdown of fat into glycerol and 3 FFA's

simple lipids

-consist primarily of triacylglycerol (TAC's)
-primary storage form (adipocytes)

compound lipids

-TAC's bound with other structures
-Functions: maintain cell integrity and manipulates fluid movement across cell membranes

Derived lipids

trans fat

saturated fatty acids

carbon binds to the maximum number of hydrogens
-no double bonds, fit close together
-occur primarily in animal products and some plants

unsaturated fatty acids

-monounsaturated contain 1 double bond
-polyunsaturated contain 2 or more double bonds

an example of essential fatty acid

what is linolenic acid?

1. low-to-moderate-intensity physical activity
2.low-calories dieting or fasting
3.cold stress
4.prolonged exercise that depletes glycogen reserves

4 conditions of mobilization of fatty acids via lipolysis

glycolipids

fatty acids bound with carbohydrates and N2

lipoproteins

protein molecule joined with a triacylglycerol or phospholipid

chylomicrons

transport Vitamins A,D,E, and K

High-density lipoprotein (HDL)

good" cholesterol

very low density lipoproteins (VLDL)

transport TAG's to muscle and adipose tissue

low-density lipoprotein (LDL)

bad" cholesterol

insulation, protection, shock absorber, energy reserves, vitamin/hormone transporter

why do we have fat?

light-intensity exercise

fatty acids provide predominant energy source in ______

moderate-intensity exercise

energy derives from equal amounts of carbohydrate and lipid in _______

high-intensity exercise

energy derives from carbohydrate, primarily muscle glycogen in _____

improves, mild-to-moderate

regular aerobic exercise profoundly _____ long-chain fatty acid oxidation, particularly TAG to active muscle to ______ exercise

true

T/F: percentage contribution of macronutrient catabolism relates to oxygen uptake of leg muscles during prolonged exercise

proteins

______ are constructed from amino acids and contain 16% nitrogen

dipeptide

two amino acids linked together

tripeptide

three amino acids linked together

polypeptide

50 to more than 1000 amino acids joined together

essential amino acids

indispensable, body cannot synthesize them so they must be consumed in food

nonessential amino acids

body can synthesize from other compounds already in body tissues at a rate to meet growth and tissue repair needs

complete proteins

exist in foods that contain all the essential amino acids in the quantity and correct ratio to maintain nitrogen balance

incomplete proteins

lack one or more essential amino acids

catabolism

nitrogen must be removed from amino acids prior to ______

Deamination

nitrogen removal, forms urea that is eliminated as urine

increase

most modes and intensities of exercise modestly ______ protein breakdown

increases

large _______ in protein synthesis occur during recovery from endurance and resistance exercise

micronutrients

significant roles to facilitate energy transfer and tissue synthesis

Fat soluble vitamins

A, D, E, K
-high doses can be toxic b/c it gets stored in the fat tissue

water soluble vitamins

C and B-complex
-act largely as coenzymes in metabolism

False
-they serve as essential links and regulators in metabolic reactions
-control tissue synthesis and protect the integrity of the cells plasma membrane

T/F: vitamins contain a lot of useful energy

intense physical activity

oxidative stress increases with _____

Regular aerobic exercise

lessens the likelihood of tissue damage from intense physical activity

Antioxidants

help neutralize vitamins and limit DNA damage
-hinder athletic performance

> 100 mg/d

7 major minerals required in amounts ____

< 100mg/d

14 trace minerals required in amounts ____

structure, function, regulate

-minerals provide ____ in forming bones and teeth
-help to maintain normal bodily______
-_________ metabolism by becoming part of enzymes and hormones that modulate cellular activity

calcium

what is the body's most abundant mineral

osteopenia

weakened bone, increasing fracture risk

osteoporosis

bone loses it's calcium mass and concentration, which causes bone to progressively become more porous and brittle with high likelihood of fracture

sodium, potassium and chlorine

what vitamins are known as electrolytes

chief minerals

sodium and chlorine represent the ______ contained in blood plasma and extracellular fluid

chief intracellular mineral

potassium serves as the ________

body water loss and loss of related minerals with water replacement the crucial and immediate need

excessive sweating during exercise produces

replaced

body water and minerals must be _____ during and following exercises

not increase

sweat loss during exercise usually does _________ mineral requirements above recommended values

40-70%

water constitutes _____ of total body mass

70%

muscle contains _____ water

10%

fat contains ____ water

62%, 38%

_____ of the body's water occurs within cells and ___ occurs outside of cells in plasma

...

loss of body water represents the ______ consequence of profuse sweating

1.Physical activity intensity
2.Environmental temperature
3.Relative humidity

what factors determine the amount of water loss

450mL

Each 0.45kg body weight loss corresponds to _____ of dehydration

hyponatremia (water intoxication)

sustained low plasma sodium concentration creates an osmotic imbalance across the blood-brain barrier.
-swells brain tissues

headache, confusion, nausea and cramping
(severe ones are seizures, coma, pulmonary edema, cardiac arrest and death)

symptoms of hyponatremia

400mL-600mL

drink ______ fluid 2-3 hours before exercise

150mL-300mL

drink _____ fluid 30 minutes before exercise

during or after

drink no more than 1000mL of plain water spread over 15 min intervals _____ exercise

ATP-PCr system

-occurs in the cytoplasm of the cell
-fastest rate of ATP production
-shortest duration at which ATP can be produced
-provides energy for tasks that demand a lot of energy in a short period of time
(sprinters)

glycolytic system

-occurs in the cytoplasm of the cell
-moderate rate and duration of ATP production

oxidative system

occurs in the mitochondria of the cell
-slowest rate of ATP production
-longest duration at which ATP can be produced
-includes krebs cycle and ETC
-does require oxygen
(distance runners)

anaerobic

no O2 required

1

ATP yield (ATP-PCr): ____ ATP per PCr

increases, increases

when ATP levels decrease, ADP _____ and CK activity _____

decreases

when ATP levels increase, CK activity ______

creatine kinase

the enzyme used to split PCr into a phosphate and creatine

phosphate

______ is added to ADP to create ATP
-acts as a reservoir of high-energy phosphate bonds

availability of primary substrate, enzyme availability

energy is produced at a controlled rate based on_______

rate-limiting enzyme

controls rate of overall reaction

negative feedback

the end product of a process in turn reduces the stimulus of that same process

the investment phase

the first few reactions of glycolysis are referred to as ______

True
-aerobic --> pyruvate
-anaerobic --> lactate

T/F: Glycolysis can be both aerobic and anaerobic

increase, increase

A decrease in ATP causes a ____ in ADP and ____ in PFK activity

decrease

An increase in ATP causes a _____ in PFK activity

decrease

when pH levels go down, PFK will _____

1, 0

In glycolysis it costs ___ ATP for glucose and ___ ATP for glycogen

2, 3

Glycolysis net ATP yield: ____ ATP for glucose and ___ ATP for glycogen

aerobic

oxygen required

1, 32-33

Oxidative system: ___ glucose= ____ ATP

1, 100+

oxidative system: ___ FFA=_____ATP

Stage 1: glycolysis
Stage 2: Krebs Cycle
Stage 3: electron transport chain

what are the steps of the production of ATP?

Acetyl-CoA

what is the first substrate in Kreb's Cycle?

B-oxidation of fat

-breakdown of fats into energy
-converting FFA's to acetyl-coq before entering the Kreb's Cycle
-every time you go through this cycle, you cut off 2 carbons

Acetyl-CoA

_____is the common entry point for carbohydrates, fat and proteins

-2-3 ATP
-2 NADH, pyruvic acid or lactate

what is the output of glycolysis?

creatine kinase

what enzyme is necessary to ATP from PCR?

high intensity exercise

oxygen debt is highest after _______

60 to 180 s

rapid and large accumulation of blood lactate occurs during maximal exercise of ________

True

T/F: lactate threshold can change with training

aerobic metabolism

steady rate _______ reflects a balance between energy required by working muscles and ATP production in aerobic reactions

oxygen deficit

Difference between total oxygen consumed during exercise and the total that would have been consumed had steady-rate oxygen uptake been achieved at the start of exercise

true

T/F: endurance-trained individuals have a smaller oxygen deficit

EPOC (oxygen debt)

total recovery VO2 MINUS total VO2 theoretically consumed at rest during recovery

1. level of anaerobic metabolism during activity
2. respiratory, circulatory, hormonal, ionic and thermal adjustments that elevate metabolism during recovery

what factors impact recovery VO2?

active recovery

-cooling down or tapering off
-includes sub maximal exercise may prevent muscle cramps and stiffness and facilitate overall recovery

passive recovery

individual lies down with minimal energy expenditure (which is believed to reduce recovery energy requirements and thus "free" oxygen to fuel the recovery process); modifications include massage, cold showers, specific body positions, and consuming cold l

1000

1 kcal = _____cal

40%

only about _____ of the energy liberated during the metabolism of glucose and fats is used to produce ATP
-remaining 60% is converted to heat

metabolic rate

rate at which the body expends energy at rest and during exercise
-typically measured at rest

resting metabolic rate

the minimum energy required for essential physiological function
-varies between 1200-2400 kcal/24hrs
-60-75% of daily energy used

PFK

what is the rate-limiting enzyme in glycolysis?

Acetyl CoA

what is the common starting point of the Kreb's Cycle?

ATP-PCr system

which does not provide NADH to the ETC?

3

the Kreb's cycle produces ____ NADH

1

Beta-Oxidation produces ____ NADH

thermic effect on a meal (TEM)

energy used for digestion, transport and metabolism of ingested food
-10% of daily energy used

thermic effect of activity (TEA)

-energy above RMR needed to perform activities
-15-30% of daily energy used
-effected by duration, intensity, size of individual and body mass

body weight, age, weight loss

what factors affect resting metabolic rate?

direct calorimetry

using the principle that energy given off in the form of heat

indirect calorimetry

a method of estimating energy expenditure by measuring respiratory gases

mitochondria

oxygen is used in the _____ to make ATP

respiratory quotient (RQ)

the ratio between volume of CO2 produced in metabolism (VCO2) and volume of oxygen consumer (VO2)

RQ=VCO2/VO2

what is the equation for RQ?

0.80

what is the RQ value typically at rest?

glucose

when O2 is limited, _____ is the preferred duel because it is more efficient

true

T/F: glucose is a limited fuel source while fat is not so fat is preferred during low intensity activities

increases

as exercise intensity _____, RQ increase

increases

energy expenditure ______ when you start exercising

2/3 fat and 1/3 CHO

shifts in substrate utilization during rest

1/3 fat and 2/3 CHO

shifts in substrate utilization during exercise

respiratory exchange ratio

reflect the ratio of CO2 produced to O2 consumed when factors other than food combustion contribute to gas exchange
-indicates that pulmonary exchange of O2 and Co2 no longer reflect only cellular oxidation of specific foods

excess CO2 production in relation to O2 uptake (lactate)

what does an RER of greater than 1 indicates?

exercise economy

the caloric cost to produce movement at a specified intensity

hyperventilation

increases CO2 to higher levels compared to current metabolic demands

buffering

produces the weaker carbonic acid during intense exercise, which degrades to CO2 and H2O with the lungs readily spelling CO2

VO2 max

the maximal capacity for oxygen consumption by the body during maximal exertion
-single best measurement of cardiorespiratory endurance and aerobic fitness

-40m dash, high jump, olympic lifts, shot put, long jump, ski jump

how can we test the immediate energy system? (ATP-PCr)

400m dash, hockey, diving, gymnastics (except vault)

how to we test the glycolytic system?

wingate test

30s super maximal effort on leg or arm cycle ergometer
-initial resistance set to 0.075 kg/BW; resistance increased after overcoming

blood lactate

level provides most common indicator of activation of short-term energy system but it may not necessarily reflect absolute levels of anaerobic energy transfer via glycolysis

glycogen depletion

depleting pattern can reveal glycolytic contribution to power the short-term energy system

VO2 Max, capillary desnity, level of aerobic enzymes, mitochondrial size and number and muscle fiber type

what are the determinants of endurance power

Absolute VO2 max

how much oxygen you use
-L/min

Relative VO2 max

this is how much oxygen you use relative to your body size

44-50

VO2 max of untrained young men?

38-42

VO2 max of untrained young women

VO2 peak

highest value of oxygen consumption measured during a graded exercise test
-if you don't see the plateau
-only occur if the person is not able to push through the exercise

10%

only about _____ of the lungs are solid tissue

aveoli

site of gas exchange between lung tissue and blood
-increase the surface area for gas exchange to occur

surfactant

a solvent that prevents water from binding so when you breathe in you're not working against the natural pressure from the water

conducting zone

-trachea and terminal bronchioles
-brings the air in from the atmosphere
-anatomical dead space

transitional

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