sports science- topic 3: energy systems

3.1.1: List the macro and micro nutrients - Macronutrients

Carbohydrates, Lipids, Protein and Water

3.1.1: List the macro and micro nutrients - Micronutrients

Fibres, Minerals, Vitamins

3.1.2: Outline the functions of macro and micronutrients - Carbohydrates

• Primary fuel source

• Energy storage

• DNA

• RNA

3.1.2: Outline the functions of macro and micronutrients - Food sources of carbohydrates

• Fruit, vegetables, root vegetables, dairy products, cereals, legumes (pulses)

3.1.2: Outline the functions of macro and micronutrients - Lipids

• Energy storage

• Cell membrane

• Hormones

• Precursor of bile acid (critical absorption and digestion of fats)

3.1.2: Outline the functions of macro and micronutrients - Food sources of lipids

• Meat, milk, dairy products, eggs, fish oil, vegetable seeds, nuts, oils

3.1.2: Outline the functions of macro and micronutrients - Protein

• Promotes growth and repair of muscle tissue

• Structure, transport, enzymes, protection

3.1.2: Outline the functions of macro and micronutrients - Food sources of protein

• meat, milk, fish, dairy products, eggs, legumes

3.1.2: Outline the functions of macro and micronutrients - Water

• medium for chemical and metabolic reactions

• transporting nutrients and waste products (excretion)

• Thermoregulation

• Helps maintain blood pressure

• Lubrication

3.1.2: Outline the functions of macro and micronutrients - Food sources of water

• Beverages, fruit, vegetables

3.1.2: Outline the functions of macro and micronutrients - Fibre

• crucial in digestive health, bowel movements, improve cholesterol and blood sugar levels

3.1.2: Outline the functions of macro and micronutrients - Food sources of fibre

• legumes, brown or wholegrain rice, nuts, root vegetables, bran based cereals, dried fruit

3.1.2: Outline the functions of macro and micronutrients - Minerals

• Essential components of molecular structures that support vital processes

• e.g. muscle contraction, fluid balance, energy systems, bone and teeth mineralisation, blood oxygen transport, and maintaining acid-base and cellular fluid balance.

3.1.2: Outline the functions of macro and micronutrients - Food sources of minerals

Meat, fish, milk, dairy products, salt, cereals, fruit, vegetables

• e.g. calcium, magnesium, iron, zinc

3.1.2: Outline the functions of macro and micronutrients - Vitamins

• Essential in small amounts for growth, development, and metabolism. They function as co-enzymes, aiding enzymes in breaking down carbohydrates, proteins, fats, and minerals

• support energy release, metabolism, bone health, immune function, and eyesight.

3.1.2: Outline the functions of macro and micronutrients - Food sources of vitamins

Fruit, vegetables, fatty fish (salmon), fish oil, liver, meat

3.1.3: State the molecule composition of a glucose molecule

C6 H12 O6

• glucose is a monosaccharide

3.1.4: Identify a diagram representing the basic structure of a glucose molecule 

3.1.5: Explain how glucose molecules can combine to form disaccharides and polysaccharides 

• via the process of a condensation reaction by which a water molecule is removed as 2 monosaccharides link together

3.1.5: Explain how glucose molecules can combine to form disaccharides and polysaccharides - Disaccharides

• formed when 2 glucose molecules join

3.1.5: Explain how glucose molecules can combine to form disaccharides and polysaccharides - examples of disaccharides

• sucrose, maltose, lactose

3.1.5: Explain how glucose molecules can combine to form disaccharides and polysaccharides - Polysaccharides

• long chains of glucose molecules

3.1.5: Explain how glucose molecules can combine to form disaccharides and polysaccharides - examples of polysaccharides

• glycogen, starch, cellulose

3.1.6: State the composition of a molecule of triacylglycerol 

• 1 glycerol, 3 fatty acids

• triacylglycerol makes up most of fats digested by humans

3.1.7: Distinguish between a saturated and unsaturated fatty acid - Saturated fatty acid

• have NO double bonds between individual carbon atoms of the fatty acid chain.

• form straight chains that are often packed together very tightly, allowing organisms to store energy very densely

• usually derived from animal produts

3.1.7: Distinguish between a saturated and unsaturated fatty acid - food sources of saturated fatty acids

• meat, poultry, full-fat dairy products, tropical oils, palm oil, coconut oil

3.1.7: Distinguish between a saturated and unsaturated fatty acid - Unsaturated fatty acid

• contain one or more double bonds between carbon atoms in the fatty acid chain

• unsaturated fat molecules contain somewhat less energy (less kJ)

• unsaturated fatty acid food usually plant based

3.1.7: Distinguish between a saturated and unsaturated fatty acid - food sources of unsaturated fatty acids

avocado, nuts, vegetable oils, soy bean, sunflower, canola and olive oils

• unsaturated fats are healthier than saturated but consumption should still be limited

3.1.7: Distinguish between a saturated and unsaturated fatty acid - molecular structure of a saturated fatty acid

NO double bonds

3.1.7: Distinguish between a saturated and unsaturated fatty acid - molecular structure of an unsaturated fatty acid

contain some double bonds

3.1.8: what are protein molecules also known as?

Polypeptides

3.1.8: State the chemical composition of a protein molecule 

Carbon, hydrogen, oxygen, nitrogen

3.1.9: Distinguish between an essential and non-essential amino acid  - what is an amino acid?

chemical units or building blocks that make up protein

3.1.9: Distinguish between an essential and non-essential amino acid  - Essential Amino Acids

• cannot be synthesised by the human body and must be obtained from the diet

• e.g. red meat, fish, poultry, eggs, dairy, soy, nuts, beans

3.1.9: Distinguish between an essential and non-essential amino acid  - Non-essential amino acids

• can be synthesised by the human body

3.1.10: Describe the current recommendations for a healthy, balanced diet - Carbohydrates

• carbohydrates should make up between 55-75% of diet

3.1.10: Describe the current recommendations for a healthy, balanced diet - Lipids

• lipids should make up between 15-30% of diet

3.1.10: Describe the current recommendations for a healthy, balanced diet - Protein

• proteins should make up between 10-15% of diet 

3.1.11: State the approximate energy per 100g of carbohydrate, lipid and protein

Carbohydrates: 1760kJ

Lipids: 4000 kJ

Protein: 1720 kJ

3.1.12: Discuss how the recommended energy distribution of the dietary macronutrients differs between endurance athletes and non-athletes - Endurance Athlete

Carbohydrates: 55-75% of diet to support prolonged exercise and replenish glycogen.

Protein: Slightly increased to support tissue repair and recovery.

Fat: Reduced to accommodate higher carbohydrate and protein intake.

Carb Needs: Vary with training load; increased on high activity days.

3.1.12: Discuss how the recommended energy distribution of the dietary macronutrients differs between endurance athletes and non-athletes - Non-endurance Athlete

Carbohydrates: 55-60% of diet.

Protein: 10-15% of diet.

Fat: No more than 30% of diet.

Balanced Diet: Supports general health without the high energy demands of endurance training.

3.2.1: Outline metabolism, anabolism, aerobic catabolism and anaerobic catabolism - Metabolism

All biochemical reactions that occur within an organism, including anabolic and catabolic reactions

3.2.1: Outline metabolism, anabolism, aerobic catabolism and anaerobic catabolism - Anabolism

energy requiring reactions whereby small molecules are built up into larger ones

3.2.1: Outline metabolism, anabolism, aerobic catabolism and anaerobic catabolism - Catabolism

chemical reactions that break down complex organic compounds into simpler ones, with the net release of energy

3.2.2: State what glycogen is and its major storage sites - Definition

Glycogen is the stored form of glucose

• polysaccharide (long chains of linked glucose molecules)

3.2.2: State what glycogen is and its major storage sites - Function

• short-term energy storage that can be quickly metabolised to meet a sudden need for glucose

3.2.2: State what glycogen is and its major storage sites - Storage sites

• Liver (75-100g), Skeletal muscles (300-400g)

3.2.3: State the major sites of triglyceride storage - Function

• storage of energy (body’s main energy reserve)

3.2.2: State the major sites of triglyceride storage - Storage sites

• Adipose tissue, skeletal muscle

3.2.4: Explain the role of insulin in the formation of glycogen and the accumulation of body fat

1. Insulin is a hormone produced by the beta cells of the pancreas

2. Insulin is secreted in response to high blood sugar level

3. Insulin lowers the blood sugar level of the body by stimulating the uptake of glucose by the liver/muscles

4. Converts the excess glucose into glycogen and stores it in the liver/muscles

5. Insulin inhibits lipolysis (breakdown of fat) and glycogenolysis (breakdown of glucose)

6. Excessive glycogen that cannot be stored will be stored as adipose tissue

7. Insulin has a fat-sparing effect and directly stimulates accumulation of fat in adipose tissue by inhibiting the release of the fatty acids from triglycerides

8. Insulin secretion promote lipogensis (synthesis of fatty acids for storage of excess glucose) and then triglycerides synthesis which may lead to increase in adipose tissue (accumulation of fat) if glucose intake exceeds energy storages

3.2.5: Outline glycogenolysis and lipolysis - Glycogenolysis

• Breakdown of glycogen - catabolic reaction

• In the liver: glycogen stored in the liver is broken down into glucose-1-phosphate then to glucose-6-phosphate which then can be released in the blood for uptake by other cells

• In the muscles: glycogen is broken down into glucose-6-phosphate and is used in glycolysis for energy production - this is where glucose is converted into pyruvate to provide immediate energy and is NOT released into the blood.

• Hormones that induce glycogenolysis are glucagon (from pancreas) and adrenaline/epinephrine (from adrenal glands)

3.2.5: Outline glycogenolysis and lipolysis - Lipolysis

• Breakdown of lipids (triglycerides) - catabolic reaction

• Fat cells: during this process, free fatty acids are released into the bloodstream and circulate throughout the body

• Triglycerides undergo lipolysis (hydrolysis by lipases - adding water) and are broken down into glycerol and fatty acids

• Hormones that induce lipolysis include adrenaline (epinephrine) and glucagon

• Lipolysis promotes the conversion of non-carbohydrate sources into glucose for the muscle

3.2.6: Outline the functions of glucagon and adrenaline during fasting and exercise

During fasting and exercise:

• low blood glucose as muscles increase uptake due to stimulus of exercise

• blood flow is increased which delivers insulin and glucose to muscles

• stimulates an increase of glucagon and adrenaline

• stimulates glycogenolysis

• glucagon (released by alpha cells in the pancreas) causes release of glucose from glycogen stores in the liver and skeletal muscle

• stimuates lipolysis

• both glucagon and adrenaline mobilise fat stores from the body’s adipose tissues for breakdown into energy

3.2.6: what is glucagon?

enzyme that helps break down glycogen

• released from alpha cells in the pancreas due to low blood sugar

• stimulates the breakdown of glycogen into glucose in the blood

3.2.7: Explain the role of insulin and muscle contraction on glucose uptake during exercise

• both insulin and muscle contraction stimulate glucose uptake from the blood into skeletal muscle.

• insulin is secreted in response to high blood sugar levels and lowers blood sugar by facilitating glucose transport into cells.

• during exercise, insulin output from the pancreas decreases.

• exercise increases blood flow, enhancing the effectiveness of insulin receptors on muscle cells, making glucose uptake more efficient.

• lower insulin levels during exercise stimulate the liver to release stored glycogen/glucose, maintaining blood glucose levels.

• exercise increases the body’s sensitivity to insulin, reducing the need for high insulin levels to transport glucose into muscle cells.

3.3.1: Annotate a diagram of the ultrastructure of a generalised animal cell

3.3.1: Animal cell - nucleus function

contains chromosomes made up of DNA and protein

• brain of the cell

3.3.1: Animal cell - ribosomes function

a cell structure that makes protein

• freely floating in the cell

3.3.1: Animal cell - endoplasmic reticulum function

manufacturing and packaging system

• smooth endoplasmic reticulum: important in the storage of lipids and steroids

• rough endoplasmic reticulum: has ribosomes attached to its surface

3.3.1: Animal cell - golgi apparatus function

processes and bundles macromolecules like proteins and lipids

• post office inside the cell as it modifies, sorts and packages proteins to be secreted

3.3.1: Animal cell - lysosomes function

secretes waste - garbage disposals

3.3.1: Animal cell - mitochondrion function

responsible for cellular respiration

• powerhouse of the cell

3.3.2: Annotate a diagram of the ultrastructure of a mitochondrion

Outer membrane, cristae, matrix

3.3.2: Annotate a diagram of the ultrastructure of a mitochondrion - outer membrane function

phospholipid bilayer that has a selectively permeable membrane

• allows ions, nutrient molecules, ATP and ADP to go through

3.3.2: Annotate a diagram of the ultrastructure of a mitochondrion - inner membrane

freely permeable to oxygen, carbon dioxide and water

• highly complex, includes electron transport system, ATP synthesase complex and transport proteins

3.3.2: Annotate a diagram of the ultrastructure of a mitochondrion - cristae function

wrinkles and folds of the inner membrane greatly increase the total surface area of the inner membrane

• allows room for the inner membrane to contain all of its complexes

3.3.2: Annotate a diagram of the ultrastructure of a mitochondrion - matrix function

contains the enzymes responsible for the citric acid cycle reaction.

3.3.3: Define the term Cell Respiration

the controlled release of energy in the form of Adenosine Triphosphate (ATP) from organic compounds in cells

• process that converts food into usable chemical energy

3.3.3: what are the 3 metabolic processes that cellular respiration can be divided into?

1. Glycolysis (occurs in the sarcoplasm (cytoplasm of skeletal muscle cell)

2. The Krebs cycle (takes place in the matrix of the mitochondria)

3. Oxidative phosphorylation via the electron transport chain (occurs in cristae)

3.3.4: Explain how adenosine can gain and lose an electron

• Adenosine Triphosphate (ATP) is the body's primary energy currency, made up of adenosine and three phosphate groups.

• ATP Hydrolysis: The breakdown of ATP (by removing a phosphate group) releases energy, which can be used for muscle contraction and other bodily functions.

• Energy Release: When ATP is broken down into Adenosine Diphosphate (ADP) and a free phosphate group, energy is released.

• ATP Synthesis: When energy is available (from food or creatine phosphate), the body reattaches a phosphate group to ADP, converting it back to ATP.

• Phosphorylation: This process of adding a phosphate group to ADP to form ATP is called phosphorylation.

ATP acts like a chemical battery, storing energy when it is not immediately needed and releasing it instantly when required by the body.

• if this occurs in the presence of oxygen, it is called aerobic metabolism or oxidative phosphorylation

• if this occurs without oxygen, it is called anaerobic metabolism

3.3.5: Explain the role of ATP in muscle contraction

1. Cellular respiration is the controlled release of energy in the form of ATP (from organic compounds in cells) through the release of a phosphate group (creating ADP) the energy released supplies the energy for the muscle contraction. No further energy can be created until ATP is resynthesised/reversed process.

2. In the muscle the coupling of myosin and actin, stimulates the breakdown of ATP.

3. ATP on the binding site of myosin breakdown ATP to ADP and release of phosphate molecule

4. Release of Phosphate (energy) allows the cross bridges to initiate power stroke, where they swivel towards the middle of the sarcomere. This is the pulling actin over the myosin, making the muscle shorter.

5. When the stimulus from the nerve stops and the muscle returns to resting state, ADP is re-joined to phosphate to reform ATP

6. A high-energy phosphate compound from which the muscle derives its energy/the main energy currency in muscle cells; ATP is used to transfer the chemical energy needed for metabolic reactions

3.3.6: Describe the synthesis of ATP by the ATP-CP system

1. ATP stored in the myosin-cross bridges is broken down to release energy for muscle contraction. This leaves the by-products from the ATP breakdown to release energy for muscle contraction. This leaves the by-products from the ATP breakdown: adenosine diphosphate and one single phosphate

2. Phosphocreatine is then broken down by the enzyme creatine kinase into Creatine and Pi

3. The energy released in the breakdown of PC allows ADP and Pi to rejoin, forming more ATP. This newly formed ATP can now be broken down to release energy to fuel activity

   Enzyme ATPase assists the synthesis of new ATP rather than the breakdown.

3.3.6: Strengths and weaknesses of ATP-PC system

Weaknesses:

• Duration of up to 10 seconds only and limited supply of CP

• For repeated bouts of all-out effort there needs to be sufficient recovery time

  Strengths:

• allows ATP to gain phosphate molecule almost instantly

• does not require oxygen

• CP is readily available

• provides energy for high intensity exercise/movement

• no fatiguing by-products

• CP can quickly resynthesise due to quick recovery time