Home >Documents >Hour 1-Gaseous Exchange

Hour 1-Gaseous Exchange

Date post:04-Apr-2018
Category:
View:216 times
Download:0 times
Share this document with a friend
Transcript:
  • 7/30/2019 Hour 1-Gaseous Exchange

    1/23

    [email protected] Slides Are Prepared By Biology Lecturer, KMPk

    mailto:[email protected]:[email protected]
  • 7/30/2019 Hour 1-Gaseous Exchange

    2/23

    7.1 Gaseous exchange and

    control in mammals

  • 7/30/2019 Hour 1-Gaseous Exchange

    3/23

    3

  • 7/30/2019 Hour 1-Gaseous Exchange

    4/23

    Describe the basic structure of

    haemoglobin and its characteristics as

    respiratory pigments. Explain the transport of carbon dioxide

    by haemoglobin.

  • 7/30/2019 Hour 1-Gaseous Exchange

    5/23

    5

    Consist of four

    polypeptide subunits;

    two chain

    two chain

    held together by

    hydrogen bond

  • 7/30/2019 Hour 1-Gaseous Exchange

    6/23

    6

    Structure of haemoglobin

    Each peptide contains

    a haem group, bind

    with oxygen

    Therefore, one

    hemoglobin (Hb)

    molecule binds

    up to fouroxygen molecules

  • 7/30/2019 Hour 1-Gaseous Exchange

    7/237

    Combines reversely with O2 to formoxyhaemoglobin in areas of high O2

    concentration region

    - releases O2in areas of low O2

    concentration region

    Hb + 4O2 Hb(O2)4

  • 7/30/2019 Hour 1-Gaseous Exchange

    8/238

    1

    dissolved in

    blood plasma

    2

    as Carbamino-

    Haemoglobin

    3

    as

    bicarbonate

    ions (HCO3-)

    CO2 transportation in blood

    CO2

    is transported between respiring tissues and

    the lungs in 3 different ways:

  • 7/30/2019 Hour 1-Gaseous Exchange

    9/239

    Air inAir inLungLung

    TissueTissueFluidFluid

    RBCRBC

    Plasma inPlasma inCapillaryCapillary

    1.1. COCO22 diffusesdiffuses

    through tissuethrough tissuecapillary wallcapillary wall

    DissolvesDissolves

    in plasmain plasma,,

    AsAsHCOHCO

    33-,-,

    Bound toBound tohemoglobin.hemoglobin.

    2.2. COCO22is carriedis carriedto the lungsto the lungs

    3.3. COCO22diffusesdiffuses

    through lungthrough lungca illary wallcapillary wall

  • 7/30/2019 Hour 1-Gaseous Exchange

    10/2310

    Only about 7% of the CO2 released by respiring cells

    is transported/dissolved in blood plasma

    In plasma,CO2

    slowly combine with water to form

    carbonic acid

  • 7/30/2019 Hour 1-Gaseous Exchange

    11/2311

    About 23% CO2

    binds to amino

    ends of the hemoglobin

    polypeptide chain to form

    carbaminohemoglobin

    the amount of CO2 that is able

    to combine with Hb depends onthe amount of O2 already being

    carried by the Hb

  • 7/30/2019 Hour 1-Gaseous Exchange

    12/23

    12

    3. As

    bicarbonate ion (HCO3

    -)

    About 70% is transported in the blood in the form

    of bicarbonate ions (HCO3

    -)

  • 7/30/2019 Hour 1-Gaseous Exchange

    13/23

    13

    3. As

    bicarbonate ion (HCO3

    -)

    CO2

    diffuses passively into

    bloodstream and passes into the

    erythrocytes.

    - combines with water to form

    carbonic acid H2CO

    3(catalysed by

    carbonic anhydrase)- then dissociates into H+ and

    HCO3

    -

  • 7/30/2019 Hour 1-Gaseous Exchange

    14/23

    14

    Accumulation of H+ will

    lower the pH of its surrounding

    H+

    tend to displace O2 fromhaemoglobin and make less

    affinity of haemoglobin for

    oxygen

    this is called the Bohr effect

    3. As

    bicarbonate ion (HCO3

    -)

  • 7/30/2019 Hour 1-Gaseous Exchange

    15/23

    15

    Hb accepts H+ fromcarbonic acid forming

    haemoglobinic acid (HHb)

    Hb acts as a buffermolecule (to minimize

    the change in blood pH)

    3. As

    bicarbonate ion (HCO3

    -)

  • 7/30/2019 Hour 1-Gaseous Exchange

    16/23

    16

    this enables large

    quantities of carbonic acidto be carried to the lungs

    without any major

    alteration in blood pH

    3. As

    bicarbonate ion (HCO3

    -)

  • 7/30/2019 Hour 1-Gaseous Exchange

    17/23

    17

    most of bicarbonate ions

    diffuse out into the plasma,

    where it is carried in the

    bloodstream to the lungschloride ions (Cl-) in the

    plasma diffuse into

    erythrocytes to replace

    bicarbonate ions

    3. As

    bicarbonate ion (HCO3

    -)

  • 7/30/2019 Hour 1-Gaseous Exchange

    18/23

    18

    This is to balance the

    loss of bicarbonate ion,

    and to maintain the

    electrical balance betweenblood plasma and

    erythrocyte

    this is called chlorideshift

    3. As

    bicarbonate ion (HCO3-)

  • 7/30/2019 Hour 1-Gaseous Exchange

    19/23

    19

  • 7/30/2019 Hour 1-Gaseous Exchange

    20/23

  • 7/30/2019 Hour 1-Gaseous Exchange

    21/23

    21

    1

    dissolved in

    blood plasma

    2

    as Carbamino-

    Haemoglobin

    3

    as

    bicarbonate

    ions (HCO3-)

    CO2 transportation in blood

    CO2 is transported between respiring tissues and

    the lungs in 3 different ways:

  • 7/30/2019 Hour 1-Gaseous Exchange

    22/23

  • 7/30/2019 Hour 1-Gaseous Exchange

    23/23

    17.1 Gaseous exchange and control in mammals

    c) describe the oxygen dissociation curve of

    haemoglobin

    d) compare oxygen dissociation curve of

    haemoglobin and myoglobin

    c) explain Bohr effect due to partial pressure

    of carbon dioxide

Embed Size (px)
Recommended