week 5: The muscular system: Integrated responses to exercise:

Question 1

why does performance rely on cardiac performance

Answer 1

it determines oxygen transport to active tissue which then used to generate energy

Question 2

what does cardiac function rely on

Answer 2

HR max
SV max ( affected by training and genetics)

Question 3

what determines how well you then use the ox delivered to tissue
(CaO2-CvO2)

Answer 3

-FIBRE TYPE
mitochondrial and capillary density (this can be affected by training)
genetics

-FlO2 (inspired)
-[Hb]
-PO2

Question 4

ATPase reaction

Answer 4

ATP > ADP + Pi + αH+

Question 5

during rest, skeletal muscle ATP storage

Answer 5

low
5-8mmol.kg-1 wet weight
enough for 8 maximal contractions/ 2seconds

Question 6

ATP supply during sprint exercise

Answer 6

stored ATP
PCr breakdown
glycolysis

Question 7

PCr breakdown

Answer 7

sits inside muscles
phosphate bounds to creatine
can liberate phosphate and transfer it to ATP quickly

Question 8

glycolysis

Answer 8

breakdown of glucose to make immediate ATP
produces pyruvate

Answer 9

glucose/ glycogen

glucose 6-P (requires 2 ATP)

fructose 1,6-DP

phosphorylated pyruvate

2x pyruvate
(4 ATP, 2 NADH produced)

Question 10

what is temporarily buffered by two reactions during severe intensity exercise

Answer 10

cystsolic ATP conc

Question 11

adenylate kinase (AK) reaction:

Answer 11

2 ADP <-> ATP + AMP

Question 12

what type of reaction is AK reaction

Answer 12

reversible buffer reaction

Question 13

what does AMP accumulation play an important role in

Answer 13

stimulating glycogen phosphorylase and phosphofructokinase (PFK)

Question 14

phosphofructokinase

Answer 14

enzyme for regulation of glycolysis
catalyses the formation of fructose-1,6-bisphosphate
(unstable two-phosphate sugar molecule)

Question 15

AMP hydrolysis

Answer 15

AMP deaminase (AD) reaction
AMP + H2O + H+ > IMP + NH4+

Question 16

IMP

Answer 16

inosine monophosphate

Question 17

when in AMP deaminase inhibited

Answer 17

when ATP conc is high

Question 18

why is AMP deaminase useful

Answer 18

can prevent acidosis by using up H+ ions

Question 19

what is IMP an activator for

Answer 19

glycogen phosphorylase

Question 20

inorganic phosphate

Answer 20

activates glycolysis

Question 21

CA2+ effect on glycogen

Answer 21

breakdown of glycogen stored in muscle liberating glucose within the muscle
do not need to wait for it from liver

Question 22

breakdown PCr reaction

Answer 22

PCr + βH+ <> Pi + Cr

Question 23

what does PCr breakdwon buffer

Answer 23

ADP accumulation

Question 24

Pi

Answer 24

substrate in glycolysis
activator of glycogen phosphorylase (GP), hexokinase (HK), and PFK in glycolysis

Question 25

why is it important Pi produced during PCr breakdown is turned back into ATP quickly

Answer 25

Pi is thought to be a major cause of muscle fatigue as it interferes with contractions

Question 26

during sprints conc of PCR, ADP, Pi….

Answer 26

PCr: decrease
ADP: increase
Pi: increase

Question 27

beginning of exercise ATP production and as exercise goes on

Answer 27

initially ATP production due to PCR breakdown (CK reaction)
As exercise goes on glycolysis activated by rising Pi and presence of ADP and AMP (after 5 seconds)

Question 28

CK isoform: mechanical machinery CK (MMCK)

Answer 28

highly expressed in cytosol

Question 29

CK isoform: mitochondrial CK (MiCK)

Answer 29

co-localised at mitochondria transfer structures

Question 30

PCr as a temporal buffer

Answer 30

provides rapid ATP provision during sprint exercise

Question 31

Pcr as a spatial buffer

Answer 31

a signalling molecule to communicate with other cellular compartments the requirements for increased ATP production

Question 32

net reaction of glycolysis

Answer 32

glucose + 2Pi + 2ADP + 2NAD+ > 2 pyruvate + 2ATP + 2NADH + 2H+ + 2H2O

Question 33

net yield of glycolsysis

Answer 33

2 ATP if started with glucose
3 ATP if started with glycogen

Question 34

pyruvate > lactate allows repsiration to occur with no oxygen present as

Answer 34

revers NADH back to NAD+
it can then be used in glycolysis

Question 35

enzyme which converts pyruvate to lactate

Answer 35

lactate dehydrogenase

Question 36

lactic acid + sodium bicarbonate >

Answer 36

sodium lactate

Question 37

sodium lactate + carbonic acid >

Answer 37

carbon dioxide
H20

Question 38

reason for VCO2 increase during anaerobic exercise

Answer 38

carbonic acid produced> H2O + CO2

Question 39

where does sodium bicarbonate come from

Answer 39

blood- main buffer for H+ to maintain blood pH

Question 40

where are cytochromes located

Answer 40

inner membrane of mitochondria

Question 41

main function of cytochrome

Answer 41

electron transport

Question 42

how do mitochondria produce energy

Answer 42

use energy stored in NADH and FADH to liberate electrons

Question 43

how do metabolic processes transport electrons

Answer 43

in the form of hydride ions H-
using NADH and FADH

Question 44

electron transport chain

Answer 44

series of electron transport proteins located in the inner membrane of the mitochondria

Question 45

how are H+ pumped from mitochondrial matrix to intermembrane space

Answer 45

redox reactions, redox-active proteins pump protons

Question 46

four protein complexes that make up ETC

Answer 46

NADH dehydrogenase
succinate dehydrogenase
cytochrome bc1
cytochrome c oxidase

Question 47

how does ATP synthase use proton gradient

Answer 47

H+ from intermembrane space travels to mitochondrial matrix through ATP synthase channels
ADP+Pi> ATP

Question 48

how many H+ needed to generate 1ATP

Answer 48

4

3H+ to generate 1ATP
1H+ used to translocate Pi (and ADP)

Question 49

electron transfer from NADH and FADH2 translocates

Answer 49

NADH: 10H+
FADH2: 6H+