exam 1 bioenergetics/ ATP-PC system

Question 1

what is the 1st law of thermodynamics?

Answer 1

CONSERVATION OF ENERGY

• cannot be created or destroyed
• one form to another

Question 2

what is the 2nd law of thermodynamics?

Answer 2

DISORDER

universe tends to move toward disorder

Question 3

what is bioenergetics?

Answer 3

transfer and use of energy in biologic systems

Question 4

what is entropy?

Answer 4

the disorder of components in a chemical system

Question 5

what is enthalpy?

Answer 5

heat content in chemical reaction

Question 6

if a reaction releases heat it is?

Answer 6

exothermic

Question 7

if a reaction absorbs heat it is?

Answer 7

endothermic

Question 8

both entropy and enthalpy are used in a mathematical equation to determine?

Answer 8

free energy

Question 9

what can free energy determine?

Answer 9

whether or not a reaction can proceed spontaneously

Question 10

what is gibbs free energy ^G?

Answer 10

change in free (available) energy

Question 11

what does gibbs free energy ^G predict?

Answer 11

if a reaction will proceed and in what direction

*can turn energy into energy-rich compounds like ATP

Question 12

if there is a net loss of energy and the reaction does proceed it is a + or a - ^G?

Answer 12

it would be a negative ^G and the reaction is EXERGONIC

Question 13

if there is a net gain of energy and a reaction does not proceed would it be a positive or negative ^G?

Answer 13

positive ^G; energy must be added to make it proceed and the reaction is ENDERGONIC

Question 14

when ^G is at zero what is happening?

Answer 14

reactants are at equilibrium

Question 15

what is a constant number for a given reaction that tells us how much free energy is available under standard conditions?

Answer 15

standard free energy

Question 16

what is a coupled reaction?

Answer 16

2 reactions happening at the same time; endergonic coupled with exergonic

• net ^G must be negative for reaction to occur

Question 17

what is ATP?

Answer 17

the energy currency of the cell

Question 18

when the bond between ATP’s phosphate groups is broken, large amounts of free energy are released, how much?

Answer 18

-7.3 kCal/mol

Question 19

the energy available from ATP can be used for?

Answer 19

1. coupling with endergonic reactions
2. transport of molecules against a concentration gradient
3. mechanical motion

Question 20

at rest how much ATP do you consume every day?

Answer 20

40kg

Question 21

during exercise how much ATP is used?

Answer 21

over 1 lb every minute

Question 22

what does AMP concentration increase?

Answer 22

1. ATP consumption
2. decreased nutrients
3. exercise

Question 23

what is AMP?

Answer 23

activated protein kinase- regulatory enzyme

Question 24

what does AMP do?

Answer 24

phosphorylates key enzymes

• increasing glucose transport
• suppressing energy requiring pathways

Question 25

what does AMP inhibit?

Answer 25

glycogen synthesis cholesterol synthesis TAG synthesis FA synthesis

Question 26

what does AMP stimulate?

Answer 26

``` GLUT4- glucose transport glycogen breakdown glycolysis fat burning lipoprotein lipase (LPLm) activation ```

Question 27

where is adenylate cyclase?

Answer 27

plasma membrane

Question 28

adenylate cyclase stimulates an energy reaction which results in?

Answer 28

cyclic AMP (cAMP)

Question 29

what does cAMP stimulate

Answer 29

a powerful enzyme- cAMP-dependent protein kinase, protein kinase A, PKA

Question 30

what shuts down glycogen synthesis and activates glycogen breakdown?

Answer 30

glucagon

Question 31

what are compounds with more free energy than ATP?

Answer 31

phosphoenolpyruvate-PEP -14.8 kcal/mol creatine phosphate -10.3 kcal/mol usually coupled with high endergonic reactions and may be used to create ATP

Question 32

PCr is what?

Answer 32

phosphocreatine AKA phosphagen system or creatine phosphate system

Question 33

where does the ATP-PC system take place?

Answer 33

mitochondria and cytosol

Question 34

phosphocreatine PCr is what type of compound?

Answer 34

high energy compound

Question 35

the ATP-PC reaction is what type of reaction?

Answer 35

a couple reaction that is a short duration in results in the fast replacement of ATP -active muscle contraction and glycolysis

Question 36

what is there more of in skeletal muscle than ATP?

Answer 36

10x PCr than ATP- its reservoir replenishes ATP

Question 37

amount of creatine in skeletal muscle is relative to?

Answer 37

muscle mass

Question 38

phosphocreatine supplies the phosphoric group for?

Answer 38

ATP synthesis

Question 39

what are the enzyme and cofactor needed for the ATP-PC reaction to occur?

Answer 39

creatine kinase and magnesium

Question 40

what does the ATP-PC system do?

Answer 40

make ATP or replenish PCr depending the direction of the reaction

Question 41

what inhibits the ATP-PC pathway?

Answer 41

EXCESS product- high energy, high ATP or low PCr

Question 42

what stimulates the ATP-PC pathway?

Answer 42

reactants- high ADP, high PCr