Chapter 2 exercise physics - fuel for exercise: bioenergetics and muscle metabolism summary

Chapter 2 exercise physics - fuel for exercise: bioenergetics and muscle metabolism summary Define substrates and give examples - fuel sources from which we make energy - breaking down large molecules (macros) to smaller ones (micros) for energy - ex: adenosine triphosphate (ATP) - other exs: carbohydrate, fat, protein (primary macromolecules) define bioenergetics - process of converting substrates into energy (either anabolic or catabolic process) - performed at cellular level define metabolism! chemical reactions in the body how is energy release measured? - can be calculated from heat produced - measured in calories what is the one constant by-product of all metabolic activity? heat (ex: sweating when you exercise) what are the major/primary macromolecules? - carbohydrates - fats (lipids) - protein when you exercise for a short period of time, what substrates are you using primarily? - more carbohydrates when you exercise for a long period of time, what substrates are you using primarily? - carbohydrates AND fat what substance are all carbohydrates converted into? glucose how many kcals are in 1g of carbohydrate? how many kcals are stored in the body? - 4.1 kcal/g - around 2,500 kcal of carbohydrates stored in the body what is the primary ATP substrate for muscles and the brain? carbohydrates! where is the extra glucose produced from carbohydrates stored? what is it stored as? stored in the liver and in muscles as glycogen on a RELATIVE basis, where is glycogen found in the body? liver on an ABSOLUTE basis, where is glycogen found in the body? muscle what are the three ways fat can be stored in the body? - subcutaneous - visceral - intermuscular (makes sense, seen this in cadavers) when does glycogen get converted back to glucose? when the body needs to make more ATP how do you replenish glycogen since it has limited storage? dietary carbohydrates (eating carbohydrates!) define fat - energy substrate for prolonged, less intense exercise (ex: you lose fat by walking on the treadmill) - efficient substrate = efficient storage how many kcals are in 1 gram of fat? - 9.4 kcal/g how many kcals of fat are stored in the body? +70,000 kcals of fat stored in the body (that is a lot more than carbohydrates) what is the relationship between fat and ATP yield and production? high net ATP yield but slow ATP production what is fat broken down into? fatty acids (FFAs) and glycerol what component of fat is made into ATP? fatty acids (FFAs) define protein - energy substrate during starvation - can also convert into FFA through a process called lipogenesis how many kcals are in 1 gram of protein? 4.1 kcal/g what must protein first be converted into? glucose via glucogenesis why does protein also have to be converted into fatty acids (FFAs)? - for energy storage - for cellular energy substrate (ex: when you're fasting, your muscle and fat are being eaten away if you are only drinking water and not eating protein, so you NEED the fatty acids!) what does controlling the rate of energy production by substrate availability mean? - energy released at a controlled rate based on the availability of primary substrate define the mass action effect - the concentration of substrates and products determines which direction a reaction will go - basically, a high concentration of A and B will produce AB and a high concentration of AB will produce A and B define the mass action effect from powerpoint!!! - substrate availability affects metabolic rate (directly proportional) - more available substrate = higher pathway activity - excess of given substrate = cells rely on that energy substrate more than others