Energy Systems Flashcards
What are macronutrients?
A type of food necessary in large quantities in the diet to support function and energy production, i.e. carbohydrate, protein, and fat.
What is the word for all of the chemical processes that occur in the body to support life including converting food into energy?
Metabolism.
What is the name of the study of how energy is transformed in living organisms?
Bioenergetics.
What are the building blocks of all living organisms?
Cells
What are organelles?
Tiny structures within cells, each with a unique function.
What is 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?
Plasma membrane
What is cytoplasm?
The viscous fluid inside a living cell excluding the nucleus.
What is the phospholipid bilayer?
The dual layer of lipids that make up the cell membrane of most human cells.
What are the smaller, absorbable building blocks of the fat that is found in the body?
Fatty acids
What is the name for the self-replicating genetic material in human cells?
Deoxyribonucleic acid (DNA)
What is gluconeogenesis?
The generation of new glucose molecules from non-carbohydrate carbon substrates.
What is glycolysis?
The breakdown of glucose by enzymes, releasing energy and pyruvic acid.
Where do cellular reacions such as gluconeogenesis and glycolysis take place?
The Cytoplasm (or cytosol)
What is mitosis?
Cell division that results in two cells identical to the original cell.
What are the small cellular organelles involved in polypeptide and protein synthesis?
Ribosomes
What is endoplasmic Reticulum (ER)?
A network of tubules attached to the nuclear membrane in cells.
What is the difference between a rough endoplasmic trticulum and a smooth endoplasmic reticulum?
A rough endoplasmic reticulum has ribosomes attached. A smooth endoplasmic reticulum does not.
What is glycogen?
The stored form of glucose found in muscle tissue and the liver.
What is the golgi apparatus?
An organelle of folded membranes responsible for packaging and transporting membrane-bound proteins. It moves proteins from inside the cell to the cell membrane to be released to their final destination in the body.
What are glycoproteins?
A class of proteins with a carbohydrate group(s) attached.
What are lysosomes?
Lysosomes serve as the digestive system of the cell. A lysosome is an organelle filled with digestive enzymes that breaks down materials the cell has absorbed.
What is the organelle with a double membrane and many folds inside responsible for generating the chemical energy needed for biochemical reactions?
Mitochondria
What is the energy-producing process that occurs in mitochondria in the presence of oxygen?
Oxidative phosphorylation
What is the simple sugar the body uses for energy production on the cellular level?
Glucose
What are the main component of adipose tissue made of three fatty acids and a glycerol molecule?
Triglycerides
What happens to carbohydrates that are not used or stored as glycogen?
They get converted to triglycerides and stored as fat.
What happens to dietary fat when it is digested?
It is broken down into fatty acids for use in energy production or triglycerides for storage in adipose tissue.
What is respiratory quotient (RQ)?
A method of determining the fuel mix being used; a way to measure the relative amounts of fats, carbohydrates, and proteins being burned for energy.
RQ = volume CO2 exhaled / volume of O2 inhaled
Are macronutrients directly used as energy?
No. Macronutrients are not directly used as energy, nor are the resulting substrates from digestion. Rather, these substrates (glucose and fatty acids) are converted into adenosine triphosphate (ATP), the energy currency of the cells - an energy-carrying molecule used to fuel body processes.
What are energy pathways?
The chemical-reaction pathways that supply the body with energy on a cellular level.
Name the energy pathways.
The ATP/creatine phosphate system (ATP/CP), anaerobic glycolysis, and the oxidative pathway.
How much work can be produced by the energy from ATP stored in the muscle cells?
About 10 seconds.
What is creatine phosphate (CP)?
A high energy molecule stored in skeletal muscle, the myocardium, and the brain.
What is the anaerobic energy system that provides rapid energy using creatine phosphate to generate ATP?
ATP/CP Energy Pathway
What is the enzyme that breaks creatine phosphate into creatine and phosphate?
Creatine kinase
During maximum-intensity activity, how long does it take to deplete creatine phosphate stores in the muscle cells?
About 10 seconds.
Give some examples of activities that the ATP/CP energy system could support.
- High jump
- 100-meter sprint
- Lifting a heavy load two to three times
What is the anaerobic energy system converting glucose to lactate when oxygen is limited?
Anaerobic glycolysis.
What energy system is used for activities that last from 10 to 120 seconds (2 minutes) and when the immediate demand for oxygen is greater than the supply?
Anaerobic glycolysis.
What is anaerobic glycolysis?
The anaerobic energy system converting glucose to lactate when oxygen is limited.
Anaerobic glycolysis produces a metabolic by-product called… (?)
Lactic acid
Name three ways the body uses lactic acid.
- To make ATP
- To make glucose in the liver
- As a signaling molecule
What is the point at which the body switches from aerobic metabolism to primarily anaerobic metabolism?
Anaerobic threshold.
What energy pathways are dominant in sustained activities lasting more than 120 seconds (2 minutes)?
Aerobic energy pathways.
What is the breakdown of glucose to ATP in the presence of oxygen called?
Aerobic glycolysis.
What is the chemical reaction of combining with oxygen or removing hydrogen?
Oxidation.
What energy pathway is a primary source of energy when the body is at rest or during low-intensity activities and uses carbohydrates and fats as the primary fuel?
Oxidative energy pathway.
What is 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.
What is the 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.
What is pyruvate?
A metabolic intermediate molecule in several energy pathways.
Aerobic glycolysis produces a metabolic by-product called… (?)
Pyruvate.
How many molecules of ATP can one molecule of fat produce?
Up to 129.
What is the process by which muscle protein is broken down or catabolized for energy?
Gluconeogenesis.
What is the condition of lower-than-normal blood glucose?
Hypoglycemia.
What is Excess Postexercise Oxygen Consumption (EPOC)?
The amount of oxygen required to restore normal metabolic status.
What is a calorie?
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 1 gram of carbohydrates?
4 calories
How many calories are in 1 gram of protein?
4 calories
How many calories are in 1 gram of fat?
9 calories
What is energy balance?
The state achieved when energy intake is equal to energy expenditure.
What is positive energy balance?
More energy is consumed than expended.
What is negative energy balance?
More energy is expended than consumed.
What is the physiological result of a positive energy balance in humans?
Weigh gain.
What is the physiological result of a negative energy balance in humans?
Weight loss.
What is 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.
Define Resting Metabolic Rate (RMR).
The energy expenditure of metabolic and physical processes when the body is at rest.
What is Thermic Effect of Food (TEF)?
The energy expenditure associated with food digestion and absorption.
What percentage of the body’s TDEE does RMR consume?
About 70%.
Define Daily Calorie Expenditure (CDE).
The total number of calories an individual expends including their resting metabolic rate, activity level factor, and the thermic effect of food.
What is Activity Level Factor (ALF)?
Multipliers that reflect varying levels of activity.
Physical activity makes up about what percent of TDEE?
About 20%
Physical activity can be split into what two distinct categories?
- Exercise Activity Thermogenesis (EAT)
- Non-Exercise Activity Thermogenesis (NEAT)
Define Exercise Activity Thermogenesis (EAT).
Energy expended as a result of planned, structured, and repetitive movement with the goal of improving or maintaining physical fitness.
Define 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.
EAT makes up about what percent of TDEE?
About 5%
NEAT makes up about what percent of TDEE?
About 15%
What are the three general body shapes?
- Ectomorph
- Endomorph
- Mesomorph
