3 Energy Systems Flashcards
List the macronutrients and micronutrients.
1.1
Macro: provide calories/energy & are required in large amounts
1. lipid (fat)
2. carbohydrate
3. protein
4. water
Micro: required in small amounts to orchestrate wide variety of physiological functions (not made by organism, except vitamin D)
1. vitamins
2. minerals
3. fibre
Outline the functions of macronutrients and micronutrients
1.2
State the chemical composition
of a glucose molecule.
1.3
C₆H₁₂O₆ (1:2:1 ratio)
simplest/empirical formula: CH₂O
Identify a diagram representing the basic structure of a glucose molecule
1.4
How are carbohydrates synthesized & classified?
Synthesized by plants from water & carbon dioxide via photosynthesis. Carbs= source of cellular metabolic energy
Classified by nr. of molecules present
1 Molecule: Monosaccharide
2 Molecules: Disaccharide
3-9 Molecules: Oligosaccharide
10 or more: Polysaccharide
Explain how glucose molecules can combine to form disaccharides and polysaccharides.
1.5
Condensation Reactions
- linking of monosaccharide to another monosaccharide, disaccharide or polysaccharide by removal of 1 water molecule
- basis synthesis of all important biological macromolecules (carbohydrates, proteins, lipids, nucleic acids) from simpler sub-units (monomers)
Give an overview of carbohydrate metabolism
Carbohydrates digested to monosaccharides -> abosrbed across gut lining & transported to liver. Then glucose transported to body’s cells.
Main users of glucose: RBC, brain, skeletal muscle, heart
Whats a monosaccharide?
most simple form of carbs (sugar), 1 molecule, easily absorbed by body, metabolic fuel
E.g.:
* Fructose
* Galactose
* Glucose
Whats a disaccharide?
Combination of 2 monosaccharides
Each disaccharide contains glucose
Formed by dehydration synthesis (condensation reaction) from removal of water
Examples:
* Glucose + Fructose = sucrose (+ water)
* Glucose + Galactose = lactose (+ water)
* Glucose + Glucose = maltose (+ water)
Whats a polysaccharide?
10 or more sugar molecules combined
energy stores or
* starch: Plants store glucose in roots & tubers, seeds, grains & some fruits -> (How plants store glucose)
* glycogen: polysaccharide of glucose, main storage form of glucose in our bodies -> (How animals store glucose)
structural compounds
* Cellulose: Many glucose molecules bound together. Non-starch found in plant cell walls. Difficult to digest and is commonly known as: FIBER
State the composition of a
molecule of triacylglycerol.
1.6
Lipids (oils, fats, waxes): consist primarily of triacylglycerols (triglycerides), also as phospholipids & sterols.
Triglycerides: composed of glycerol molecule & 3 fatty acid chains
- Stored in adipose tissue & skeletal muscle
Function:
- Long-Term Energy Storage
- Fat in adipose tissue protects vital organs & helps to control body temp.
- Dietary Fat, synthesis of hormones, vitamin D (sterols) and cell membranes (sterols, phospholipids)
Distinguish between saturated
and unsaturated fatty acids.
1.7
Saturated Fats: no double bonds btw. individual carbon atoms of fatty acid chain.
- originate from animal sources (e.g. meat, poultry, full-fat dairy products, tropical oils)
- usually solid at room temp.
Unsaturated Fats: contain 1+ double bonds btw. carbon atoms in fatty acid chain
- originate from plant-based foods (e.g. oilive oil, olives, avocado, peanuts, cashew nuts, canola oil & seeds, sunflower oil & rapeseed)
- can be monounsaturated or polyunsaturated
State the chemical composition
of a protein molecule.
1.8
Protein= polymer of amino acids (AA)
- linked in chains via peptide bonds
- body breaks down food into AA & makes own protein
- composed of C,H,O,N
Distinguish between an essential
and a non-essential amino acid
1.9
Essential amino acids cannot be synthesized by human body & must be obtained from diet (8/20)
Non-essential amino acids can be synthesized by the human body.
Describe current
recommendations for a healthy
balanced diet.
1.10
Balanced Diet: provides all nutrients in right amount to maintain health & prevent disease
- methods used to identify level of adequate intake of nutrients vary internationally
Dietary Recommendations: recommended amounts of essential nutrients in the diet
- No internalional agreement about dietary recommendations
Dietary Guidelines: Recommended amount of foods, food groups or meals
State the approximate energy content per 100 g of carbohydrate, lipid and protein.
1.11
** Kilojoules (kJ)** common measure of amount of energy you get from consuming a food or drink
- Joule = a single unit of energy -> 1000J = 1kJ
100g protein: 1720kJ
100g lipid: 4000kJ
100g carb: 1760kJ
Discuss how the recommend energy distribution of the dietary macronutrients differs between endurance athletes and non-athletes.
1.12
Annotate a diagram of the ultrastructure of a generalized animal cell.
3.1
Annotate a diagram of the ultrastructure of a mitochondrion.
3.2
Explain how adenosine can gain
and lose a phosphate molecule.
3.4
Bonds btw. 3 inorganic phosphate groups are very energy-rich. Energy is released when ATP molecule combines w/ water, loosing its last phosphate.
Reverse process is phosphorylation- ATP synthesized by adding phosphate group to compound adenosine diposphate (ADP)
Describe the re-synthesis of ATP by the ATP–CP system.
3.6
Creatine Phosphate (PCr)- High energy compound present in muscles.
Creatine Kinase Reaction- liberates chemical energy to synthesize ATP
- ANAEROBIC ENERGY SYSTEM
- Creatine Phosphate + ADP + H+ ↔ Creatine + ATP
- PCr broken down to provide phosphate molecule for re-synthesis of ATP that was used during initial stages of exercise (first 2 sec)
- Occurrs quickly & very important in hard exercise (e.g. sprints)
- Reaction can occur in both directions: when at rest & muscle recovers from exercise ATP can be used to refill PCr store in muscle
Describe the production of ATP by the lactic acid system.
3.7
*ANAEROBIC ENERGY SYSTEM
*
Glycolysis-metabolic pathway in cytoplasm that releases energy in glucose as ATP & produces pyruvate. When oxygen is absent (high intensity exercise) or mitochondria in limited supply pyruvate is converted to lactate and 2 ATP. Small ATP supply can meet demands of high intensity exercise when PCr input fades for a short while until lactic acid accumulation reduces muscle pH -> discomfort & muscle contraction ability decreases.
Explain the phenomena of oxygen deficit and oxygen debt.
3.8
Oxygen Deficit: The body needs oxygen from the moment we begin to exercise. The body gets into oxygen deficit because oxygen need and oxygen supply do not match .
Oxygen debt is now known as excess postexercise oxygen consumption (EPOC).
- EPOC: During recovery, oxygen use continues at a rate greater than what is needed at rest.
- additional oxygen demands persist during recovery, needed for processes like restoration of tissue & myoglobin oxygenation
Discuss the characteristics of the three energy systems and their relative contributions during exercise.
3.10
Evaluate the relative contributions of the three energy systems during different types of exercise.
3.11
As exercise intensity increases, describe the change in energy requirement and provision (of ATP):
- 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
Explain which energy systems are predominatly used for the following exercise intensities: Rest, Moderate, Brisk and Maximal
- Rest: Aerobic (Fat and Carb). Moderate: Aerobic, Anaerobic (Lactic). Brisk: Anaerobic (Lactic), Aerobic (Carb) Maximal: PCr, Anaerobic
Explain the use of Fatty Acids and Carbohydrates (Glucose) as exercise intensity increases.
- Glucose is used throughout all exercise intensities (Aerobic at low intensity, Anaerobic Lactic Acid at higher intensities. Fatty Acids are only used at lower intensity exercise. Above 90% of max exercise, no fatty acids are used as fuel.
