What do athletes eat and why?
Introduction to Energy Describe how the breakdown of ATP occurs to provide energy State the main sources of energy for the replenishment of ATP and describe how they are used
WHAT DO ATHLETES EAT AND WHY? In pairs write down answer on A3 sheet
All chemical reactions in cells need a molecule called ATP to provide them with energy. ATP is the ‘energy currency’ of the cells. Energy is the capacity to do work Energy is measured in joules (J) or kilojoules (kJ)
ATP = Adenosine Triphosphate ATPase ENERGY ADP + Pi + ENERGY!
How does ATP provide energy? Each cell contains a ‘pool’ of ATP which is used to provide energy – enough for 2-3 seconds of exercise The energy in ATP is chemical potential energy between the phosphate bonds. ATP is hydrolysed (broken down using water) by the enzyme ATPase to produce ADP + Pi (ADP = adenosine diphosphate + phosphate group) In this reaction the bonds between the final phosphate group is broken, releasing energy Enzymes can use this energy to drive chemical reactions. Once ATP has been broken down, it can be reformed from ADP + P using energy from fuels such as glucose
ATP – ADP Cycle Energy input from fuels e.g. glucose ATP Synthesis + ADP + Pi ATP ATP Breakdown by ATPase Energy released to be used by cells
Resynthesising ATP Energy Source Where is it found in the body? How much energy/ ATP can it make? How it is used to synthesise ATP Phospho-creatine (PCr) Glycogen Triglycerides Protein
Energy Source Where is it found in the body? How much energy/ ATP can it make? How it is used to synthesise ATP Phospho-creatine (PCr) Small amounts stored in the muscle cells 1 ATP per PCr molecule PCr is broken down into P and Cr, and this releases enough energy to synthesise ATP Glycogen Muscle (350g) and liver (100g) 2 ATP per glucose in high intensity, anaerobic conditions, 38 ATP per glucose in low intensity, aerobic conditions. Yields 4kcal/gram Glycogen is broken down into glucose which is used in anaerobic or aerobic respiration.
Only used when glycogen stores are running out, amino acids are converted into a molecule that is used in aerobic respiration Similar to carbohydrate – yields 4kcal/gram muscle tissue itself Protein Triglycerides are broken down into fatty acids and glycerol, which go through a process called beta oxidation, and can then be used as fuel for aerobic respiration when plenty of oxygen is available. Used in conjunction with glycogen. Over twice as much per gram as compared to glycogen – yields 9kcal/gram. Muscle stores and stores in adipose tissue around the body. Triglycerides How it is used to synthesise ATP How much energy/ ATP can it make? Where is it found in the body? Energy Source
Write down the 3 key points of this lesson! Whiteboard or App
Exam Question Gymnastic events can last up to 90 seconds. Explain how the majority of energy is provided for these events. (7 marks)
Mark scheme 7 marks for 7 of: A. Anaerobic/without oxygen B. (during first few seconds) stored ATP splits/breaks down initially/ATP breaks down to ADP + P + energy C. ATP-PC/system/phosphocreatine system/alactic system D. PC = C + P(i) + energy/creatine + phosphate/PC broken down; E. Energy used for ATP resynthesis/ADP + P + energy = ATP/ADP + PC = ATP + C; F. Lasts 5-10 seconds/limited supply G. Lactic acid system/Lactate anaerobic system H. Glycogen/glucose breakdown I. Glycolysis J. To pyruvate/pyruvic acid K. Lactate/lactic acid formed