Unit 4: Energy Systems Flashcards
What are the types of macronutrients? (4)
- lipids
- carbohydrates
- proteins
- water
What are the types of micronutrients? (3)
- vitamins
- minerals
- trace elements
What is the function of carbohydrates?
metabolic fuel and energy store
What is the atomic ratio of a carbohydrate?
C1H2O1
monosaccharide
simplest carbohydrate and is easily absorbed by human body
disaccharides
2 monosaccharides bonded together
polysaccharides
many monosaccharides bonded
Glucose (3)
- monosaccharide
- broken down by cells to provide energy
- C6H12O6
Condensation Reaction (2)
- bond molecules
- one water molecules is removed for each bond formed
Hydrolysis Reactions (2)
- break apart molecules
- one water molecules is added for each bond broken
What are examples of polysaccharides? (3)
- starch
- glycogen
- cellulose
Starch (2)
- a polymer of glucose
- used by plants to store glucose when it it not needed by cells for energy
Glycogen (3)
- polymer of glucose
- used by animals to store glucose when it’s not needed for energy
- stored in liver and skeletal muscle
Cellulose (4)
- a polymer of glucose
- a micronutrient
- in cell walls of plants and helps prevent disease when ingested
- dietary fiber
dietary fiber
indigestible molecule
What are the functions of fats? (4)
- energy source
- energy storage
- protects internal organs
- insulates and helps maintain internal body temperature
What is the monomer of a fat?
triacylglycerols
What is the structure of a triacylglycerol? (2)
- 1 glycerol
- 3 fatty acid tails
What is the structure of a fatty acid? (2)
- carboxyl groups
- hydrocarbon tail
Saturated
only single bonds in hydrocarbon tail
Unsaturated
1or more double bonds in hydrocarbon tail
Where do saturated fats originate from? (2)
- animal sources
- tropical oils
What do saturated fats do?
raise cholesterol
Where do unsaturated fats originate from?
plant oils (ex: olive oil and avocado)
monounsaturated fats
1 double bond in hydrocarbon tail
polyunsaturated fats
multiple double bonds in tail
omega-3 fats
1st double bond located between 3rd and 4th carbon from methyl end
omega-6 fats
1st double bond located between 6th and 7th carbon from methyl end
Trans fats (2)
- saturated fats formed by adding hydrogen to unsaturated vegetable oils under pressure
- have negative health effects
Which fats have negative health effects? (2)
- saturated fats
- trans-unsaturated fats
Which fat has a positive health effect?
cis-unsaturated fats
What are the functions of the proteins? (5)
- structure
- protection
- transport
- enzymes
- energy
What atoms does protein contain? (4)
- carbon
- oxygen
- hydrogen
- nitrogen
How are proteins made?
when amino acids are linked together using condensation reactions
What does it mean for an amino acid to be essential?
they are made by the body
What macronutrient provides the most energy per gram?
lipids
How many kJ (kilojules) and calories are provided by 100g of lipids? (2)
- 4000 kJ
- 900 cal
How many kJ (kilojules) and calories are provided by 100g of carbohydrates? (2)
- 1760 kJ
- 400 cal
How many kJ (kilojules) and calories are provided by 100g of proteins? (2)
- 1720 kJ
- 380 cal
Dietary Recommendations
give daily intake of essential macro and micro-nutrients
Dietary Guidelines
dietary advice on how to get correct amounts of macro and micro-nutrients
What is daily nutrient intake based on? (3)
- age
- gender
- activity level
What is the recommended calorie intake for males?
2000-3000
What is the recommended calorie intake for females?
1600-2400
Which macronutrient is the primary energy source?
carbohydrates
How do macronutrients in diets of endurance and non-athletes differ? (2)
- the diet of an athlete needs to meet the increased physiological requirements
- athletes require increased energy and fluid requirements
What does an endurance athlete need in their diet? (4)
- increased carbohydrate intake
- increased protein intake
- higher fat intake
- increased water intake
Metabolism
all life sustaining chemical reactions
What are the purposes of metabolism? (3)
- convert food to energy
- eliminate nitrogenous waste
- convert food to monomers and build new molecules
Catabolism (3)
- chemical reactions that break down larger molecules into smaller ones
- energy is released
- uses hydrolysis reactions
Aerobic catabolism
processes that require oxygen to break down molecules and release energy
Anaerobic catabolism
processes that don’t require oxygen to break down molecules and release energy
Anabolism (3)
- chemical reactions in which small molecules are linked to form larger molecules
- requires an input of energy
- uses condensation reactions
What happens to carbohydrates when they are eaten? (3)
- first digested into monosaccharides
- blood transports monosaccharides to liver
- glucose is stored in liver and skeletal/muscle cells
Glycogenesis (3)
- storing glucose by linking glucose molecules to form glycogen (condensation reaction)
- occurs if consume more glucose than needed for energy
- glycogen is stored in liver and skeletal muscle cells
Glycogenolysis (3)
- breakdown of glycogen into glucose (hydrolysis reaction)
- capable of happening rapidly
- occurs when body need more glucose than what is provided by food
How does glycogenolysis occur in the liver? (2)
- glycogen is broken down into glucose
- liver glycogen provides glucose for all organs, but not skeletal muscle
How does glycogenolysis occur in the skeletal muscle? (2)
- glucose is broken down into glucose-6-phosphate
- muscle glycogen is only used in muscle as energy source
What happens to fats when they are eaten? (3)
- fats are broken down by pancreatic enzymes and bile in the small intestine
- fats are broken down into fatty acids
- fatty acids are used or stored for energy
What is stored as triacylglycerol?
excess fat that we consume and don’t use for energy
Where is triacylglycerol stored? (2)
- adipose tissue
- skeletal muscles
Lipolysis (2)
- release of triacylglycerides form body’s fat stores
- provides energy when not available form diet or glycogen stores
What do hormones control? (2)
- the conversion of glucose to glycogen
- break down of glycogen to glucose
What are the characteristics of the lactic acid system during exercise? (6)
- occurs in the cytoplasm
- anaerobic
- uses glucose as fuel
- 1 glucose makes 2 ATP
- lactic acid is a by product
- is dominant for up to 3 minutes
What causes the pancreas to release insulin?
increase in blood glucose
What does insulin signal?
uptake of glucose by liver fat, and muscle cells
What is glucose used for once in the cells? (2)
- to make energy
- glycogenesis
What happens when insulin levels are high?
blood glucose levels fall
Insulin
hormone that helps maintain a stable level of blood glucose
What does insulin inhibit? (4)
- conversion of protein/fat into glucose
- break down of fat for energy
- break down of proteins for energy
- glucagon
What causes the pancreas to release glucagon?
a decrease in blood glucose
Glucagon
hormone that signals the break down of glycogen into glucose in the liver
What does glucagon stimulate? (2)
- glycogenolysis
- lipolysis
What happens when glucagon levels are high?
blood glucose levels increase
What hormonally happens during exercise? (2)
- adrenaline is released, which inhibits the release of insulin
- prevents insulin’s role in signaling glucose storage
What does adrenaline stimulate? (3)
- glucose uptake by skeletal muscle
- glycogenolysis in muscle
- lipolysis
How do muscles increase glucose uptake during exercise? (3)
- adrenaline stimulates glucose uptake by muscle cells
- higher exercise intensity = greater uptake
- glucose is done by moving glucose transporters to the cell membrane
What do cells break macronutrients down for?
energy
Where is energy stored?
ATP
ATP
provides energy for cellular activities
What are the structures of an animal cell? (6)
- ribosome
- rough ER
- lysosome
- mitochondria
- nucleus
- golgi apparatus
ribosome
make proteins for inside the cell
rough ER
produce protein for export
lysosome
digest cellular garbage
mitochondria
produce ATP in the presence of oxygen
nucleus (2)
- stores DNA
- directs activities of the cell
golgi apparatus
helps process and package proteins for export
Where is ATP made?
in the mitochondria where oxygen is present
cellular respiration
the controlled release of energy from the break down of organic compounds to produce glucose, lipids, proteins, and ATP
How is ATP produced? (2)
- by adding ADP to a phosphate group
- the formation of ATP requires energy from food
How is ATP broken down?
ATP is hydrolyzed in a phosphate group and ADP
What does the break down of ATP release?
energy that can be used for cellular work
How is ATP used for muscle contractions?
the energy released by the breakdown of ATP into ADP and phosphate provides energy for muscle contraction
How much ATP is in the muscles?
enough ATP for two seconds of muscle activity
How many energy systems does the body have to make ATP?
3
What are the energy systems the body uses to make ATP? (3)
- creatine phosphate system (ATP-CP system)
- lactic acid system
- aerobic system
Which system is the fastest to make ATP?
creatine phosphate (PCr) pathway
Creatine Phosphate (4)
- high energy compound
- cannot directly make energy
- forms ATP from ADP and P
- quickly resynthesized so recovery time is fast
What is the formula in the creatine phosphate system?
creatine phosphate + ADP —> creatine + ATP
How long does the PCr system last?
the first 10 seconds of intense exercise
When is creatine phosphate in the muscle refilled?
during low intensity exercise using ATP
What are the strengths of the ATP CP system? (3)
- makes ATP very quickly
- doesn’t require oxygen
- CP is readily available
What are the weaknesses of the ATP CP system? (3)
- used up quickly
- additional energy source required beyond 10 seconds
- repeated bouts of exercise require sufficient recovery time
Which system is the second fastest in making ATP?
the lactic acid system
What happens after the first 10 seconds of high intensity exercise?
ATP is produced by the lactic acid system
How long does the lactic acid system last?
2-3 minutes
What is another name for the lactic acid system?
anaerobic glycolysis
Glycolysis
catabolic pathway that breaks down glucose for energy in cytoplasm of cells
Lactic Acid System (4)
- anaerobic
- breaks glucose into 2 pyruvate and releases 2 ATP
- pyruvate is converted to lactic acid
- reduces performance
What happens as intensity continues under the lactic acid system?
lactic acid begins to build up
How long until high intensity exercise can no longer be maintained?
3 minutes due to limitations of the anerobic systems
How long does it take for the body to increase oxygen levels?
3-5 minutes, so the aerobic system is fully functioning
Oxygen deficit
a difference between oxygen required for a given rate of work and the oxygen actually consumed
How does oxygen deficit differ in a trained athlete compared to a untrained athlete?
- trained athlete increase oxygen level quick than untrained athlete
- oxygen deficit is smaller
What happens to energy systems when oxygen is present?
the product of glycolysis (pyruvate) enters the mitochondria where they are used to make ATP
How many steps are there in the aerobic system?
3
What are the 3 steps in the aerobic system?
- glycolysis
- Krebs cycle
- Electron Transport Chain
How much ATP is made from 1 glucose in the aerobic system?
38
Aerobic System Stage 1: Glycolysis (2)
- glucose is broken into 2 pyruvates in the cytoplasm to make 2 ATP (no oxygen needed)
- oxygen is needed for pyruvate to enter a mitochondrion
Aerobic System Stage 2: Krebs Cycle (2)
- pyruvate is broken down to produce energized electrons and 2 ATP in the mitochondria
- Energized electrons move to electron transport chain
Aerobic System Stage 3: Electron Transport Chain
energized electrons are used to make 34 ATP in the mitochondria
What are some facts about the aerobic system? (3)
- aerobic respiration can break down carbohydrates, fats, and proteins to make ATP
- fats can be used by the Krebs Cycle
- fats release more electrons than carbs and make more ATP
Which macromolecule can be used for all exercise intensities?
glucose because it can be used aerobically and anaerobically
Which macromolecule breakdown is the slowest? (2)
- fat break down is the slowest
- only used during lower intensity exercise
When does creatine phosphate contribute to exercise?
during brief, high intensity exercise
How is the contributions of energy systems determined?
by breaks in pace of the fitness of individual
What does intense exercise require?
a high rate of ATP that can only be achieved by lactic acid system and CP
excess post-exercise oxygen consumption (EPOC)
continuous use of oxygen at high rates after exercise even though muscles are no longer working (oxygen debt)
