Exam 1 P1 Information

Bioenergetics

Rest; physical work (activity)

Energy systems for muscular activity in the human body are designed to produce energy during _____________ and for _____________ at varying rates

Bioenergetics

the chemical process of converting food into energy

Basal metabolism

Direct measurement of how much energy the body needs to sustain life at rest (measured with cadaver)

Resting metabolism

Indirect measurement (estimation) of how much energy the body needs to sustain life at rest

total calories of activity (energy expenditure), energy system used during each activity, and intensity

What is taken into account when thinking about energy for activity?

5-10%

How much energy is expended on the thermal effect of food (absorbing and transporting food)?

60-70% (increases during recovery)

How much energy is expended on basal metabolic rate?

10-40%

How much energy is expended on physical activity?

NOT the same

Measurement of work is _____________ as measurement of energy.

Calorimetry

Measures energy expenditure

Direct Calorimetry

Measures heat produced from energy

Bomb calorimetry (nutrition tags), Room Calorimetry

What are the types of direct calorimetry?

Indirect calorimetry

measures gas exchange, which is an estimation of energy production

Laboratory procedures, real life conditions

What are the types of indirect calorimetry?

Laboratory conditions (Ex, RMR, REE)

measurement of oxygen uptake and carbon dioxide production

Real life conditions

Doubly labeled water technique where stable isotopes of H and O are ingested, then urine and blood are analyzed for H and O to measure carbon dioxide fluctuation

Age, Gender, Natural hormonal activity, Body surface area, body composition, and very low-calorie diets

What are bodily factors that may affect REE?

Exposure to cold/hot weather, altitude, cigarette smoking, caffiene

What are environmental factors that may affect REE?

60; 40

At rest about __% of energy is from fat and about __% of energy is from carbohydrates

fat can allow an individual to utilize more fat at rest and during exercise

Diet may affect the energy source usage at rest and during exercise because…

increases

All physical activity ________ the metabolic rate

INTENSITY!!

What is the most important factor affecting the metabolic REE?

48 hours; because that time houses our biggest anabolic recovery period

How long does the intensity of a workout affect REE, and why?

carbohydrates and fats; protein

Indirect calorimetry is specific to ______________, NOT __________

Carbohydrate to fat usage ratio and various intervals and intensities (aerobic expediture)

What does a VO2max tell us that affects nutrition

Protein metabolism, performance of an athlete, or what their diet should be

What does a VO2max NOT tell us

Metabolism

sum total of all physical and chemical changes that take place within the body

anabolic metabolism

constructive process (growth/building)

catabolic process

breakdown processes

Acetyl coA

All 3 macronutrients are broken down in their own metabolic processes to form ________.

Acetyl coA → enters Krebs Cycle → Electron Transport Chain → ATP

What is the pathway for Acetyl coA?

ATP + H₂0 ←→ ADP + Pi + H⁺ + energy

What is the ATP/ADP pathway?

ATP-PCr system

What energy system do we use for the first 30 seconds of a short, high-intensity activity?

glycolysis

What energy system do we use for 30 seconds to 3 minutes of a short, high-intensity activity?

aerobic metabolism

What energy system do we use for longer than 3 minutes of a short, high-intensity activity?

10-12 mins, in very structured levels

How long is an accurate VO2 max measurement?

ATP-PCr system

What is the body’s fastest way to produce energy during short bursts of intense activity?

Fat metabolism

What is the primary energy source for basal metabolic rate?

ATP

The cell maintains _________ at ALL times.

Creatine kinase

What enzyme breaks down PCr to release energy to add a phosphate back to ADP to turn it back into ATP again?

1. It doesn’t need oxygen so it is quicker

2. It doesn’t change pH levels like other forms of anaerobic metabolism do

What are the two benefits to the ATP-PCr system?

Cytosol

Where does the ATP-PCr system occur?

ATP

What molecule do muscles use to contract?

Creatine

If the ATP-PCr system can replenish itself quickly, then what is the rate limiting step?

Anaerobic recovery (ex. jogging for a little after sprinting)

What is needed to regenerate PCr optimally? Give an example

Exogenous source of energy

Dietary sources, ex. something we have to consume

Endogenous source of energy

Already in the body as either blood glucose or glycogen

Muscle and liver

Where are the two places in the body that store glycogen?

Red blood cells

What is the only type of cell that can ONLY use glucose for energy?

1600 Calories or 400 grams

About how much glycogen is stored in muscle?

400 Calories or 100 grams

About how much glycogen is stored in the liver?

Muscle fiber, type, and size (largely due to genetics)

What causes the amount of glycogen stored in skeletal muscle to vary?

~5L

What is the approximate blood volume in an average human adult?

~72-99 mg/dL

What is the optimal concentration of blood glucose when fasting?

~140 mg/dL

What is the optimal concentration of blood glucose for up to 2 hours post meal?

Return to normal, typically ~72-99 mg/dL

What is the optimal concentration of blood glucose 2+ hours post meal?

Carbohydrates

What is the only energy source that can be used in both anaerobic and aerobic systems?

skeletal muscle

During exercise, only glycogen from ___________ will be used for energy.

primary organs (brain + RBC) and maintains blood glucose

What does liver glycogen fuel?

to generate glucose so it can enter glycolysis

What is the goal of glycogen breakdown?

Pyruvate or lactate

What are the 2 end products of glycolysis?

Krebs cycle; aerobic

Pyruvate goes through what cycle to produce ATP? Is this cycle anaerobic or aerobic?

Cori cycle; anaerobic

Lactate goes through what cycle to produce ATP? Is this cycle anaerobic or aerobic?

Is NOT

Lactate _______ responsible for muscle soreness

lactate threshold

Intensity of exercise at which lactate accumulates faster than it is removed

2 net ATP; 3 net ATP

How much ATP is produced through glycolysis for glucose, and for glycogen?

Glycolytic enzymes

What can adapt to training and ultimately improve performance by increasing ATP availability?

Glycogen phosphorylase, Phosphofructokinase (PFK), Lactate dehydrogenase (LDH)

What are the 3 enzymes that improve efficiency with training adaptation?

increase; increases

As we __________ the exercise, enzymatic activity also ___________

1. Increased intramuscular glycogen

2. Improved buffering capabilities

3. Increased ATP availability

What are training adaptations for glycolysis?

1. Change in pH impacts muscular fatigue levels, force, and power

2. Maintaining pH can maintain energy levels, force, and power

3. Maintaining pH leads to improved recovery processes and less muscle damage

Why do buffering agents in the body matter?

Heart → kidneys → liver → skeletal muscle during low-moderate intensity

What is the order of where fat is primarily used as a fuel source?

80,000 to 100,000C; 2,500 to 2,800 C

What is the average amount of stored fat in the body? How much of it is stored in muscle cells?

Signals

Adipose tissues send out a lot of ___________.

1. Health

2. Energy (endurance)

3. Hormonal responses

4. Recovery

What is the role of body fat for performance?

Carbon Chain

The amount of ATP produced from fat depends on the ____________.