Lecture 11

Question 1

what is metabolism

Answer 1

sum of all chemical reactions in the body

Question 2

what is a metabolic pathway

Answer 2

a series of individual reactions that result in the formation of an end product

Question 3

what are the two functions of metabolic pathways

Answer 3

catabolism = breakdown of energy yielding molecules

anabolism = building energy yielding molecules

Question 4

what is the 1st law of thermodynamics

Answer 4

energy cannot be created or destroyed; it can only be converted from one form to another

Question 5

what is the 2nd law of thermodynamics

Answer 5

systems tend to go from a high to a low state of potential energy

Question 6

what is free energy

Answer 6

energy from a reaction that can be used for work

• chemical potential energy drives mechanical work of exercise

Question 7

is ATP stored in the body

Answer 7

only a very small amount is stored in muscle and other cells

Question 8

is anabolism endergonic or exergonic

Answer 8

anabolism is endergonic

Question 9

is catabolism endergonic or exergonic

Answer 9

catabolism is exergonic

Question 10

what is an exergonic reaction

Answer 10

releasing energy = “downhill” process

Question 11

what is an endergonic reaction

Answer 11

requiring energy = “uphill process”

Question 12

why are some reactions coupled

Answer 12

because some reactions require energy so they can be coupled with a reaction that releases energy so they both occur spontaneously

Question 13

maximal sustainable exercise intensity depends on ….

Answer 13

factors limiting energy transfer

Question 14

what are factors that affect energy transfer

Answer 14

1. mass action
2. enzymes (activity)
3. co-enzymes
4. temperature
5. pH

Question 15

what is mass action (factor affecting energy transfer)

Answer 15

mass action ratio = product / substrate

• the reaction will move in the direction that has less according to the mass action ratio

Question 16

what are enzymes role

Answer 16

they act as catalysts

Question 17

are enzymes reusable

Answer 17

yes they are

Question 18

are enzymes substrate specific

Answer 18

yes they are

Question 19

what is the role of co-enzymes

Answer 19

facilitate action of enzymes
- help bind substrate with enzyme
- temporary carrier of intermediary proteins

Question 20

where is creatine phosphate stored

Answer 20

in muscle

Question 21

what is creatine phosphate continually regenerated from

Answer 21

from free creatine

Question 22

where is free glucose found and is it maintained

Answer 22

in the blood stream (limited), little in muscle

• maintain fairly constant - this is important

Question 23

where is glycogen stored and which store is used first

Answer 23

stored in the muscle and the liver

• the muscle is used first

Question 24

why is muscle glycogen used first

Answer 24

it is already in the muscle so doesn’t need to be transported

Question 25

what happens when liver glycogen is used

Answer 25

• liver glycogen broken down to glucose
• into blood
• into muscle
• transported across muscle membrane

Question 26

do you ever just use one energy system at a time

Answer 26

no, we use a combination of energy systems, one will most likely be more dominant depending on what we are doing

Question 27

how quickly will the phosphocreatine energy system deplete

Answer 27

within seconds

Question 28

how quickly will the anaerobic glycolysis system deplete glycogen and what does it produce

Answer 28

minutes
- produces lactate

Question 29

how quickly will the aerobic glycolysis energy system deplete

Answer 29

moderate rate
- ~ hours

Question 30

how quickly will the aerobic lipolysis energy system deplete

Answer 30

slowly
~ days