Module 4-Energy Systems and Metabolism

MACRONUTRIENTS:

A type of food necessary in large quantities in the diet to support function and energy production

3 macronutrients

fat, carbs, protein

GLUCOSE:

A simple sugar the body uses for energy production on the cellular level

Glycogen

made up of many connected glucose molecules.

• TRIGLYCERIDES

• A chemical compound formed when three fatty acids combine with glycerol.

what is the most abundant fat in the body?

• TRIGLYCERIDES

adipose tissue

(body fat)

fatty acids

the smaller building blocks of fats

• (anabolism)

• Growth and maintenance of tissue

ATP

adenosine triphosphate (ATP) An energy-carrying molecule used to fuel body processes

ATPase

enzyme that breaks down ATP

adenosine diphosphate (ADP)

created when ATP is broken down along with a free phosphate

how many molecules of ATP does a single muscle contraction series need?

2

The respiratory quotient

(RQ) is a calculation that estimates which macronutrient is predominantly being used for fuel at a point in time.

indirect calorimetry.

the ratio of the volume of carbon dioxide expired (breathed out) to the volume of oxygen being consumed (breathed in)

The RQ for carbohydrates

1.0

RQ for fat

0.7

RQ for protein

0.8

METABOLISM:

All of the chemical processes that occur in the body to support life including converting food into energy.

3 energy pathways

the ATP/creatine phosphate system (ATP/CP), anaerobic glycolysis, and the oxidative pathway

ENERGY PATHWAYS:

The chemical-reaction pathways that supply the body with energy on a cellular level

how long can ATP stores maintain supply

10 seconds

ATP/CP ENERGY PATHWAY:

The anaerobic energy system that provides rapid energy using creatine phosphate to generate ATP.

pathways most used for less than 10 seconds of exertion

Creatine phosphate (CP)

also known as phosphocreatine, is a high energy molecule stored in skeletal muscle, the myocardium, and the brain.

CP is only found in small amounts in the muscle cells where it is stored.

During maximum-intensity activity, CP stores can be depleted in less than 10 seconds

Creatine kinase

the enzyme that breaks CP into creatine and phosphate.

Anaerobic glycolysis

uses one molecule of ATP to convert glucose to glucose phosphate.

produces a metabolic by-product lactic acid

pathway most used for 10-120 second duriations of exertion

lactic acid

• also called lactate, is used in the body in three ways:

  1. To make ATP

  2. To make glucose in the liver

  3. As a signaling molecule

they lead to muscular fatigue and muscular soreness

Gluconeogenesis

the process by which muscle protein is broken down or catabolized.

The aerobic energy pathways

pathway most used for dominant in sustained activities lasting more than 120 seconds (2 minutes) and include the process of aerobic glycolysis, fatty acid oxidation, and, in extreme circumstances, gluconeogenesis

the oxidative energy pathway is a primary source of energy when the body is at rest or during low-intensity activities.

alanine

most prominently used amino acid to create energy in cells during glucogenesis

hypoglycemia

excessively low blood glucose level

• AEROBIC GLYCOLYSIS:

• The breakdown of glucose to ATP in the presence of oxygen

• OXIDATION:

• The chemical reaction of combining with oxygen or removing hydrogen

• KREBS CYCLE:

• A series of chemical reactions inside the mitochondria that use acetyl-CoA to generate ATP and other substrates that contribute to the electron transport chain

• ELECTRON TRANSPORT CHAIN

• A series of proteins in the mitochondrial membrane that transfer electrons and
  hydrogen ions across the membrane to generate ATP from ADP

pyruvate,

the by-product of the oxidative energy pathway which serves as a transitional molecule in the many stages of aerobic metabolism

acetyl coenzyme A

Pyruvate is broken down into acetyl coenzyme A

(oxidative phosphorylation).

hydrogen ions released during the Krebs cycle move into the electron transport chain (

energy system overlap.

anaerobic and aerobic metabolism happen simultaneously during exercise

Glycolysis

the breakdown of glucose

STEADY-STATE EXERCISE:

Exercise that maintains a steady level of exertion from start to finish

EXCESS POSTEXERCISE OXYGEN CONSUMPTION (EPOC):

The amount of oxygen required to restore normal metabolic status

ANAEROBIC THRESHOLD:

The point at which the body switches from aerobic metabolism to primarily anaerobic metabolism

lactate threshold

the point where muscle tissue begins to make large amounts of lactate (exponential increases)

LACTIC ACIDOSIS:

The accumulation of excess H+ causing muscle fatigue and soreness

• BIOENERGETICS:

• The study of how energy is transformed in living organisms.

• CELLS:

• The building blocks of all living organisms

• Organelles

• tiny structures within the cell, each with a unique function

• PLASMA MEMBRANE:

• The cellular membrane made of lipids and proteins that forms the external boundary of the cytoplasm and regulates the passage of molecules in and out of the cytoplasm

• phospholipid bilayer,

• The membrane of a cell with two layers made up of lipids (fats) and protein:

  • it is made up of glycerol, two fatty acids, and a phosphate group.

semipermeable

meaning some molecules can pass through it.

• CYTOPLASM:

• The viscous fluid inside a living cell excluding the nucleus

  • The cytoplasm is the site of many cellular reactions such as the following:
    • Gluconeogenesis
    • Fatty acid synthesis
    • The activation of amino acids
    • Glycolysis

The nucleus

The organelle that has its own membrane and holds deoxyribonucleic acid (DNA).

The nucleus of the cell also initiates mitosis

DEOXYRIBONUCLEIC ACID

(DNA): Self-replicating genetic material in human cells.

chromosomes

DNA strands which contain the genetic blueprints for each unique cell in the human body

(mitosis).

cell division

Ribosomes

small, spherical organelles made of protein and (RNA), involved in polypeptide and protein synthesis

ribonucleic acid

RNA

the endoplasmic reticulum

(ER) (A network of tubules attached to the nuclear membrane in cells)

Ribosomes can attach to this organelle

rough endoplasmic reticulum.

An ER with ribosomes attached

• A smooth endoplasmic reticulum

• has no ribosomes attached.

  • The SER’s primary role in the cell is to produce lipids and, in some cases, metabolize them and associated products.

  • A SER is also involved in the production of steroid hormones in the adrenal cortex and endocrine glands.

Golgi apparatus

creates vesicles—or transport bubbles—that move proteins from inside the cell to the cell membrane to be released to their final destination in the body.

glycoproteins

proteins that have attached carbohydrate groups.

• LYSOSOMES-

• These organelles serve as the digestive system of the cell.

  • Lysosomes have about 50 different enzymes that break down materials the cell has absorbed.

The digested product in a lysosome is either used to create cellular energy or can be used to create a new molecule

• Mitochondria

• the powerhouse of the cell.

  • They are small, complex organelles that contain their own DNA.

oxidative phosphorylation

the process by which mitochondria convert macronutrients into chemical energy for the cell

CALORIES (CAL):

The amount of energy needed to raise the temperature of 1 kilogram of water by 1°C (4,184 joules) at a pressure of 1 atmosphere

how many calories are in a gram of protein?

4

how many calories are in a gram of carbs?

4

how many calories are in a gram of fat?

9

ENERGY BALANCE:

The state achieved when energy intake is equal to energy expenditure

• POSITIVE ENERGY BALANCE:

• More energy is consumed than expended.

• NEGATIVE ENERGY BALANCE:

• More energy is expended than consumed

TOTAL DAILY ENERGY EXPENDITURE (TDEE):

The accumulated calorie burn made up of resting metabolic rate, the thermic effect of food, physical activity, and physical growth.

• RESTING METABOLIC RATE (RMR):

• The energy expenditure of metabolic and physical processes when the body is at rest.

  • It includes the energy required to support cardiac function and respiration, repair internal organs, maintain body temperature, and balance water and ion concentrations across cell membranes.

  • It consumes about 70 percent of the body’s TDEE in a 24-hour period and is the most influential of the physical processes consuming energy

  • The RMR is directly correlated to body size and sex

Bland-Altman analysis

widely used to predict an individual’s RMR using the following formulas:

Men = 66.4730 + (13.7516 x weight in kg) + (5.0033 x height in cm) – (6.7550 x age in years) Women = 655.0955 + (9.5634 x weight in kg) + (1.8496 x height in cm) – (4.6756 x age in year

2 physical activity catagories

exercise activity thermogenesis (EAT) and non-exercise activity thermogenesis (NEAT).

EXERCISE ACTIVITY THERMOGENESIS (EAT):

Energy expended as a result of planned, structured, and repetitive movement with the goal of improving or maintaining physical fitness.

• NON-EXERCISE ACTIVITY THERMOGENESIS (NEAT):

• Energy expended as a result of any movements of the body that require energy.

  • This includes all activities of daily living outside of planned and
    structured workouts

• THERMIC EFFECT OF FOOD (TEF):

• The energy expenditure associated with food digestion and absorption.

  • The heat liberated from a particular food during digestion, whether it is fat, protein, or carbohydrate, is determined by its individual molecular structure, and this structure determines its thermic effect.

DIET-INDUCED THERMOGENESIS:

The thermic effect of macronutrient digestion and absorption

DAILY CALORIE EXPENDITURE (DCE):

The total number of calories an individual expends including their resting metabolic rate, activity level factor, and the thermic effect of food

• The Harris-Benedict equation

• used to estimate total daily calorie expenditure (DCE).

  • This calculation incorporates the RMR and an activity level factor (ALF) that accounts for the individual’s daily physical activity level and the TEF

ACTIVITY LEVEL FACTOR (ALF):

: Multipliers that reflect varying levels of activity

lifestyle

The lifestyles people lead include their dietary patterns, activities, and even their opinions and behaviors

WEIGHT MANAGEMENT:

The physiological processes and techniques one uses to achieve or maintain a specific body weight

• SOMATOTYPE:

• Categories of physical body type.

3 somatotypes?

ectomorph, endomorph, and mesomorph

ectomorph

Long and lean with little bodyfat and little muscle mass

Narrow shoulders and hips

endomorph

Thicker, rounder build with lots of bodyfat and lots of muscle mass

Large upper arms and thighs

mesomorph

Athletic, muscular build with broad shoulders and a healthy body weight