Topic 3: Energy systems Flashcards
List the macronutrients
Carbohydrates, Proteins, Lipids (fats), Water
List the micronutrients
Vitamins, minerals
Outline the function of macronutrients
Carbohydrates: Fuel, energy storage, cell membrane, DNA, RNA
Lipids (Fats): Fuel, energy storage, cell membrane, hormones, precursor of bile acid
Protein: Structure, transport, communication, enzymes, protection, fuel
Water: Medium for biochemical reactions, transport, excretion
Outline the functions of micronutrients
Vitamins: Energy release from macro units, metabolism, bone health, blood health, eyesight
Minerals and trace elements: Minerlizations of bones and teeth, blood oxygen transport, defense against free radicals, muscle function
State the chemical composition of a glucose molecule.
The molecular formula of glucose is C6H12O6 (1:2:1 ratio)
Identify a diagram representing the basic structure of a glucose molecule
Explain how glucose molecules can combine to form disaccharides and polysaccharides.
Condensation reaction
Condensation reaction: The linking of a monosaccharide to another monosaccharide, disaccharide, or polysaccharide by the removal of a water molecule.
State the composition of a molecule of triacylglycerol.
Triglycerides are made up of a glycerol molecule and 3 fatty acid chains.
Saturated fats
Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain.
Saturated fats originate from animal sources, for example meat, poultry, full-fat dairy products and tropical oils, such as palm and coconut oils.
unsaturated fats
Unsaturated fatty acids contain one or more double bonds between carbon atoms within the fatty acid chain.
Unsaturated fats originate from plant-based foods for example olive oil, olives, avocado, peanuts, cashew nuts, canola oil and seeds, sunflower oil and rapeseed.
State the chemical composition of a protein molecule
Formed by amino acids
Linked in chains through peptide bonds
The body breaks down food into amino acids and then makes its own protein.
Distinguish between an essential and a non-essential amino acid.
Essential amino acids cannot be synthesized by the human body and must be obtained from diet.
Non-essential amino acids can be synthesized by the human body.
State the approximate energy content per 100 g of carbohydrate, lipid and protein.
Joule = a single unit of energy 1000J = 1kJ
1720kj = 100g protein
1760kj = 100g carbohydrate
4000kj = 100g fat
outline metabolism
Metabolism: All the biochemical reactions that occur within an organism, including anabolic and catabolic reactions.
outline anabolism
Energy requiring reactions whereby small molecules are built up into larger ones.
outline catabolism
Chemical reactions that break down complex organic compounds into simpler ones, with the net release of energy.
outline anaerobic catabolism
Anaerobic catabolism: Compounds breaking down in the absence of oxygen
State the major sites of triglyceride storage.
Most fats are stored in the body as Triglycerides or Triacylglycerol in the adipose tissue and skeletal muscle
Explain the role of insulin in the formation of glycogen and the accumulation of body fat.
Not only does insulin tell the body to store excess glucose as glycogen, but it also stimulates lipogenesis or the formation and storage of Triglycerides. This occurs by;
1) The uptake of fatty acids by fat cells, which are converted to triglycerides. Triglycerides are then stored for future use in the adipose tissue as body fat.
2) The conversion of excess glucose into triglycerides, which are also then stored in the adipose tissue as body fat
Outline glycogenolysis
When the body needs more glucose than it has from the diet, it breaks down the glycogen stores in the liver and muscle, back into to glucose.
Outline lipolysis.
Triglycerides are released into the bloodstream and broken down into fatty acids and glycerol
Outline the functions of glucagon and adrenaline during fasting and exercise.
Exercise or prolonged time with no food, blood glucose drop detected by pancreas, glucagon released by α-cells of pancreas, stimulates glycogenolysis, increased blood glucose levels and use.
Adrenaline: Also increases with low glucose levels and also promotes glycogenolysis and lipolysis
Annotate a diagram of the ultrastructure of a generalized animal cell.
golgi bodies = Golgi apparatus (animal cells have no cell wall or chloroplasts)
Annotate a diagram of the ultrastructure of a mitochondrion
Define the term cell respiration
Cell respiration is the controlled release of energy in the form of ATP from organic compounds in cells.
Explain the role of ATP in muscle contraction.
ADP is transformed into ATP by myosin at the myosin head, this allows the pull of the sarcomere. ATP is the energy needed for a muscle contraction to occur.
Explain how adenosine can gain and lose a phosphate molecule.
Phosphate groups are very energy-rich
Gain: When a phosphate molecule is added back through energy ADP can be made
Loose: ATP is combined with water it loses a phosphate molecule which results in ADP
Describe the re-synthesis of ATP by the ATP–CP system
Creatine phosphate (a high energy molecule) is broken down to provide a phosphate molecule for the re-synthesis of ATP that has been utilized during the initial stages of exercise.
Describe the production of ATP by the lactic acid system
Also known as anaerobic glycolysis—the breakdown of glucose to pyruvate without the use of oxygen. Pyruvate is then converted into lactic acid, which limits the amount of ATP produced (2 ATP molecules)
Explain the phenomena of oxygen debt
Oxygen debt is now known as excess postexercise oxygen consumption (EPOC).
Oxygen debt is defined as the extra volume of oxygen that is needed to restore all the energetic systems to their normal state after exercise.
Explain the phenomena of oxygen deficit
Oxygen deficit is when the need of oxygen and oxygen supply do not match in the first moments of exercise
Describe the production of ATP from glucose and fatty acids by the aerobic system
in the presence of oxygen pyruvate is processed by the Krebs cycle which liberates electrons that are passed through the electron transport chain producing energy (ATP).
Fats are also broken down by beta oxidation that liberates a greater number of electrons thus more ATP. In the presence of oxygen and in extreme cases protein is also utilized.
Discuss the characteristics of the three energy systems and their relative contributions during exercise
As exercise intensity increases, so too does the requirement for ATP. At higher intensity exercise, ATP requirements immediate and in a large amount. At lower intensity exercise, ATP requirement is more slow and constant
Evaluate the relative contributions of the three energy systems during different types of exercise.
Depending on the sport different energy systems will be used e.g. rugby is endurance based (aerobic) however also has quick energy needed for a tackle (creatine phosphate)
