Cellular  Respira,on  Lab  Notes  

Circulatory  system:    (over-­‐simplified)  

+ 36-38ATP Depending on the tissue type, Eg. Skeletal muscle vs. cardiac muscle

pH  of  Common  items  

pH  range  of  Blood  ~7.3  –  7.4  

 [  H+  ]  ;    pH  value    [  H+  ]  ;    pH  value  

A  comparison  of  strong  and  weak  

acids  Which  soluHon  is  a  strong  acid?  A  weak  acid?  

HOW  DO  YOU  KNOW?  

✔  

Exercise  produces  excess  Acid  (metabolic  waste)    i.e.  lacHc  acid  and  carbonic  acid  

Transport  of  O2  and  CO2  in  the  blood  

Body  Cells  

Lungs  

Venous  blood  is  slightly  acidic  @  pH  7.35!    Why?  

Arterial  blood  is  neutral  @  pH  7.4!    Why?  

(Proton  donor)  “Weak  Acid”  

(Proton  acceptor)  

CO2  (from  CR)  in  the  blood  combines    

with  H2O  in  the  blood  to  form  H2CO3    

pH  of  ~  6.5  

(forced  rapid  breathing-­‐  allows  for  the  kid  to  blow  off  the  CO2)  

RegulaHon  of  Blood  pH  by  the  Respiratory  System  -­‐  the  bra4y  kid  in  the  candy  store  scenerio    

Input    

(nerve  impulse)  

Output    

(nerve  impulse)  

                 Response  

Decreasing  pH  

HypovenHlaHng  

Blood  pH  (increased  levels  of  H+  in  concentraHon)  

ppCO2      

   H+  ;  pH  <  7.3  

detect        H+    

causes        H+    

pH  >  7.3  

enzymes CO2 + H2O ⇔ H2CO3

⇔ H+ + HCO3-

M e t a b o l i c Carbonic acid Bicarbonate Waste

Sample condition #2: Respiratory Alkalosis Hyperventilation - [↓ CO2] ; [↓ H+] ; ↑ pH of blood Respiratory Alkalosis: results from a depressed ppCO2 ( < 35 mm Hg) in arterial blood and a blood pH of > 7.45 i.e. the reaction is driven to the left in this case.

Causes of Respiratory Alkalosis:1) High altitudes2) Pulmonary disease, e.g. Asthma, pneumonia, stroke3) Anxiety4) Hyperventilation due to any of the above causes, or voluntarilyhyperventilating- swimmers were once encouraged to do this in orderto hold their breath longer.

e n z y m e s

CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3

-

M e t a b o l i c Carbonic acid Bicarbonate Waste

CO2  in  the  blood  combines  with  H2O  in  the  blood  to  form  H2CO3    

(Delayed  breathing-­‐  allows  for  the  diver  to  stay  under    water  longer.    >  9  mins.  Is  the  record)  

RegulaHon  of  Blood  pH  by  the  Respiratory  System  -­‐  Why  a  free  diver  might  hypervenHlate  before  the  dive!  

Input    

(nerve  impulse)  

Output    

(nerve  impulse)  

                 Response  

Increasing  pH  

Blood  pH  (decreased  levels  of  H+  in  concentraHon)  

Diaphragm  contracHons  are  delayed  while  CO2  levels  climb  in  the  blood  

As  more  H2CO3  forms  and  more  H+  is  present,  blood  pH  decreases  (H+  concentraHon  increases)  

HypervenHlaHng  ppCO2      

   H+  ;  pH  >7.4  

detect        H+    

causes          H+    

pH  <  7.4  

Control  Experimental    

pH  of    >  7  

Control  with  water  and  phenolphthalien  

Experimental    

pH  of    <  7   pH  of    >  7  

Phenolphthalein  Indicator