biology module chap 7

8/3/2019 Biology Module Chap 7

1/14

Gaseous Exchange across the Respiratory Surfaces and Transport ol Gases inIrumansLEARNING OUTCOMESDescribe the process of gaseous exchange across:h: sl:-,:::of the alveolus and blood capillaries in the lungsExplain the transport of respiratory gasesExplain the process of gaseous exchange between the Dio,JC c'.1body cellsDistinguish the conrposrtion of inhaled and exhaleci air

Gaseous exchange across the surface of alveolus and blood capilaries

Blood entering theblood capillary hasa higher partialpressure of carbondioxide and alower partialpressure ofoxygen. ---.- Q

: .- -^ :-, - -J ,=3i i v :, =biooc cacrlla;y hasa higher cartralc'essu:e cfcxyge:r anC alciver caniapressuie of carbond roxrde

EffectsOxygen diffuses from theaivec!i ntc ti'e cloodcariiialresCarbon dioxi,Je diifusesfrnm ihe hinn,i n:niiiarrocinto tne ai'.,eoli

{.j

iI!

t-

t-!''it_

t-

t

Gaseous exchange across the surface of thealveolus and blood capillaries in the lungs.

summarises the differences between the partial pressure of oxygen and carbondioxide in the air of the alveoli and in the blood capiilaries.

Air in the alveoliHioh

summarises the differences between the partial pressure of oxygen and carbondioxide in the tissue capillaries and body cells.Partial pressureIFsue-eepilary: qcg_qgjlsHiqh

Oxygen diffuses into red blood cells

Capillary vrall

Diffuses out of blood plasma

Carbon dioxide

Carbon dioxide

i6r


2/14

,,r

,l

I

a) Transpcrt c: cx','qen1. Oxygen in the orocc :ral reaves tne alveolr is transpofted io body cells for cellularrespiration.2. Orygen is then ccnb;nes',v;'th a oigment called haemoqlobin which is contained in the

red blood cells3. A haemoglobin mclecuie ccnsists of four units, each with a heme group that has aferum atorn ett ils cenier4. oxygen is canied in the form of o{rha_emoglo-bin to all parts of the body.

lungsHaemoglobin + oxygen : oxyhaemogiobin

b) Transport of carbon dioxide iTrt1. carbon dioxide released by body cells can be transported in ihi-ee ways:

a) as dissolve carbon dioxide in the blood plasma ( 7%)b) combines with haemoglobin as carbarninohaemoqlobin (23To\c) transported in the biood in the form of bicarbonqte ions ( Hcq-) eao ).

By usino the informalicn below. complete a graphic diagram to make it easier to understand.Blood plasru Red Blood cells

The transporl of respiratory gases irr lrurrralts

Body cells release CO2 and diffuses intoblood plasma then combines with the redblood cells.Carbon dioxide reacts wiilr water to formcarbonic acid ( HzCO:)Red blood cells contain the enzymecarbonic anhydrase to catalyse thisreaction.. The cafuenic aciC then disscciates into ahydrogen ion and a bicarbonate ion.. Most of the bicarbonate ions diffuse intothe blood plasnna and are carried in the

. The bicarbcnate icns Ci,{use frs.q-. iheblood plas;-na in'.o ine r.ed blooo cells andform carbcnic acid again. Carbonic aid 5:eaks dowr1 i: carbondioxrde anc water. Carbon dioi.ice .:ffuses froi.:r ile bloodcapillaries intc the aiveoii tnus expelledduring exnaiaiion

F. r:-Scoie Teocher's Ediiion ?0C5

I

Cor

_ bloocjp]me-lg rhe tungs. iFrom the blood caoitlaries to the atveoti i Blood capillaries

\___Y-___-_JLungs

I,-JI(){\ Bio-KlI l0


3/14

Eio Scor,:

The excltancte of respiratory qases betwecn ttre blood and bodv cells.I :36i ih .f,aseous exchange belorv.

:r:"

I

i

tissue clipiilrriv

Exchange of gases between the blood and body cells

1. ln the tissue capillaries, the partial pressure of oxygen in the blood is hiqher than thepartial pressure of oxygen in the cells.Oxyhaemoglobin breaks down and releases oxvqen, which then diffuses through thecapillary walls irito the cells.Cellular respiration produces carbon dioxide thus, the partial pressure of carbondioxide is hiqher in the cells than the partial pressure of carbon dioxide in the tissuecapillaries.Carbon dioxide diffuses out of the cells into the tissue capillaries .

The composition of inhaled and exhaled air

i

2

4.

i

t

Content lnhaled air Exhaled airOxygen 21.09 o/o 16.4 %Carbon dioxide 0.03 % 4.1 0/Nitrogen 79.0 o/o 79.0 o/o.ty'ater vapour Varies an! is never saturated Saturatedrei"nperature Room temperature Body temperature

r69 Bio-KlT l0


4/14

.t

,!

r

7.4 The Regulation Mechanism in RespirationLEARNING OUTCOMESr Describe the ctiange rn the rate of respiration after con'rpierltg vrgcr.cusexercisec Correlate the rate of respiration with the oxygen and carbon droxrdecontents in the bodyc Explain the regulatory ntechanism of oxygen and carbon dioxide contenlsin the bodyo Explain the hunrarr respiratory response and rate of respiration ir.rdifferent situationso Correlate the rate of respiration with the rate of heaftbear

Corelation the rate of respiration with the oxygen and carbon dioxide contents in thebody.

During viqorous exercise, the muscle require more oxvqen and qlucose to releaseenerqv during cellular respiration. Therefore the rate of respiration increases.ln order to supply more oxygen, the rate and depth of breathing increases.This means the breathinq rate increases.At the same time, the heartbeat rate increases to pump more blood into circulation.This is to enable more oxygen and glucose to be suppried for ceilurar respiration andfor more carbon dioxide to be removed from the cells.6. The ventilation rate also increases.7. Rate of ventilation is the rate of gaseous exchanqe between the alveoli and b|ogdcapillaries

The regulatory mechanism of carbon dioxide content in the body

center

The respiratory centi'e in ine cra,n

1.

2.34.5.

l\f- ingiuiri. ll \ ^I.i.-.,,r -' .\ -t ! llf i -: :raii:\ \:

I 7ij


5/14

i '. i.. -' :.' .-.:. "i :1 The fesfirralory .centre td lccated in the nrecjLti ;_...irii-)ncala2. The centrS]lllenlq-Lgegple-i is a scecific ce ii i..ir.- : {cuno in the respiratory cenire\. ^--.=l a^^-s^t/:f ;^. - ilvr iLL, '(rottw, : v.

carbon dioxide

pH value in thecerebrospinal fluid andblood drops

{i

ioef* f'c o,( u*+*4 ,_.. {ff!a

tCentralchemoreceptors

Increased concenlration ofcarbon dioxide( During vigorous exercise )

Breathing rate'and,'ertiiation rate increaseC02 + H:O-_*

RESPIRATORYCENTRE

The regulatory mechanism of oxygen content in the bodylIt{t

l{

JI

l'I

I

&

s':t

LJt

Jtrtgt

:

:3 rct,ct bodyt:A r: i: i;ja r": (:'

... Ii. .if\-:1 .\-t-..".,ri' '! 1-lil. !{',ii\ i trli. 1. . jlri,. :..'t*Zf":--+ a.''- -;. -+.- ,-"

.- a:'.:::c b0(i .t!;r ': e aortic;:3'1 a

--- n*art

Position of carotid and aortic body

Nerve ifrrpulses

Normal concentration ofoxygen

Decreased concentration ofoxygen( at very high altitude )

RESPTRATORY iCENTRE I


6/14

i)

L;

j .: r ':.,r !;-ajilra'r -li)fli\Tne periphefal chemoreceptors called the aortic bodies and carorid bodics areiocaied in the lvalls of the aofla arch and caiotid a(eries in the neckrl,e','.r" mcre sensilrve tc the exchange of oxygenconcentration rn the blood::1'fei'ed to exchange cf carbcn droxrde content and the pH of the blood

I NUMBERS

;: ..,iii t-..'i:.,: cerelrrospinirl flurci

\ *Fi;i:j:\ti*''oAortic body60

EXPLANATIONDetects the AecrejiDetects the changes of carbon dioxide concentrationDetects the pH changes .

Transfer of impulsesi Rate of heartbeat increased

Rate of ventilation increasedBleath tAglgl;nd dggpgl / rate oiiespiration is rrrcreasea Ourrng vrgorousexeroses so that more oxygen is taken in and more carbon dioxide to beremoved from the cells

fl.{ci. -J, i -.t.;ii i\ @.)The regulatory mechanism of oxygen and carbon dioxide content in the body

According to the numbers given in the diagram above , state what happened when there area change in oxygen and carbon dioxide contents of the body .

2 i Nerve imoulsesII ' \vopIo(vry usilt,tE dr. iltcuuila oolonqala. ugrt-....---I changes of pH in blood and cerebrospinalfluid.

ir;i41ri.r,@g?.;.,ffi.

172 Bio-Klr l0


7/14

iir,t,\ar)fe ieochsr : ECrlii.The human respiratory response and rate of respiration irr different situations.

RESPOI'ISES_The breathing rate isRELAXING The heartbeat rate rsminute.

18 to 20 breaths per minutebetween 60 to 70 beats ier

DURING VIGOROUS ACTIVITIES Activities rr"h ".exercise, playing badminton , can give the breathingrate increases to about 30 breaths per minute, whilethe heartbeat increases to 120 beats per minute .

IN FEAR The breathing and the heartbeatlaGslncreaseThe higher respiration rate is needed to generatemore enerqv to the person to cope better in fear.The adrenal glands secrele lhe adrenalinehormone. This hormone increases the heartbeatand breathing rates.More glucose and oxvqen are supplied to themuscle.This prepares the person to respond to thedangerous situation.The atmospheric pressure is low and lead to

AT HIGH ALTITUDES difficult in breathi nq.The decreased partial pressure of oxygen causesa drop in the oxygen level of the blood.lnitially, a person will experience headaches,nausea and dizziness.After a few days, the body will becomeacclimatised to the condition.

$:u**.

I-

IIIIt

tIt

iII!t Iilt:-i,lI

rl,,

173

il


8/14

7.5 Tlre lmportance of Maintaining a Healthy Respiraiory System

r. Care and LEARNiNG OUTCOMESmaintain efficient functroning of the respirato:.), oigersThe air we inhale contains dirt, dust. soot,various irritanis 3lrii n3imi,.;i pollutants.A smoker inhales smoke which contains gases like carbon monoxide tar andnicotine.Cigarette smoke contains over 4000 chemicalsmonoxide, acetone, benzene and formaldehyde

which include tar. nicotine, carbon

4. These chemicals are carcinoqenic compounds.v,ihich can cause luno cancer

@.lD

AmmoniaCadmiumAcetoneMethanol

Carbon monoxideNaphtaleneVinyl Chloride

TolvyneHydrogen cyanide

1

2

@- ArsenicDibenzacridineNaphtala rnineButaneBenzeneBenzopvrenehl:.n nr:n=

DDT

FormaldehidePyrenePcloniunr-2'l 0LUCU

--+-__iI

IiI--1---III-t_-II-..J-

The chemicai ingiedtents !vnict-, cc.ri.ir !i c!. aierra

Bio^KlT l0


9/14

! ! J'l a'r :JOf{'I

CARBON MONOXIDE. Competes rv;ih oxvqen i: i ":with haemoqlobin 6::; isr;.rcarboxv haemoqlobin. lt reduces tte supolT cioxygen tc i:r3 cells.NITROGEN DIOXIDE' Can dissolve rn mucus tc for'::ran acidic medium rvhich

erodes iung tissue.

HEAT AND DRYNESS. lritation the lungs and can lead:o laryngitisMakes speakinq difficult andpainful.l'oBACCOS\IOKES'SCONTAIN

Avoid ciqarettesmoking

t

6.

7.

5. Two of the most common types of COPD (Chronic Obstructive Pulmonary Disease) areEmphvsema and Chronic bronchitis.Emphysema is a desease in rvhich thedamaqed.Chronic bronchitis is the lmflammationof fluid and lead to frequent couqhinq.

walls between the air sacs in the lungs areof the bronchi that can caused overproduction

Eat a healthv dietAlways do physical activities

I To reduce i

//1

,/./ ,i;l

.l:L_.

TAR. Contarn nicotine. stimulate the production ofcancer cell in trachea and lung.. Constrict the blood vessels andmake the heart to pump harderand will increase the bloodpressure.

3,4 BENzO-(o)-PYRENE' Carcinoqenic chemical thatcan cause cancer.

A'.'o!C smoky and dustyenvironmentplenty of water

r75 Bio-KlT l0


10/14

fr Brn Sao:e I.-()a .r,

7 6 Respiration in PlantsLEARNING OUTCOMESDescribe the energy requirement in plantsExplain the intake of oxygen for respirationExplain aerobic and anaerobic respiration in plantsCompare and contrast photosynthesis and respirationRelate light intensify with compensation pointPredict the situation when the rate of photosynthesis and respirationremain at compensation point

Energy requirement in plant.1 Plant derive their energy from cellular respiration.2- During cellular respiration, plant cells take in oxvqen and produce carbon dioxide3. Photosynthesis only occur in the presence of light. ln darkness, plants carry outrespiration. Plants need energy continuously to sustain their living process.The intake of oxygen by plants for respiration

1. Gaseous exchange between plant cell and the environment occurs by diffusion throughstomata and lenticels.

Structure of stomata and lenticel2. The stomata of most plants open when there is liqht and they close in the dark.3 Lenticels are raised pores found on lhe stems and roots.4 The cells around the lenticels are arranged loosely to allow the diffusion of qases rnio

and out of the plant tissue

lenticel

t76


11/14

a1i

i

Labelthe diagram below artd r)ark the pathway of oxygen and carDOn droxroe excnange

Guard cell olsloha

Oz COzThe pathway of gaseous exchange in a leaf4. Oxygen from the atmosphere diffuses to the air spaces and then into the mesophvll

cells. During aerobic respira{ion, oxygen concentration in the cells rs lower than theconcentration of oxygen in the air spaces, thus allows it to diffuse from :he air spacesinto the cells.Carbon dioxide which is produced during aerobic respiration is usecj inphotosvnthesis during the day . Excess carbon dioxide diffuses into air spaces andthen through the stomata into the atmosphere

fr

Il.iIt

:l

I

tf:IlLit-Fii(5.

il]t


12/14

Aerobic and anaerobic respiration in plants1 Aerobrc reslriaiion rs JSti:ilv c3l.i.reJ 3iit:t,piants throughoul fhe day and night2 Unoe, can:ir cl.ci,lrcr.s s:a,r 3s:_::iJ flcocinq, pian,l can alsc carny out anaerobicrespiration for short periods3 Anaerobrc respiraiion also occu:s c,:,i.1 ire initrai stages of qermination when theembryo is completely encloseo l.linin 6 seeo coal

Respiration and photosynthesis1 Respiration and photosynthesis are oepenoent on each other.2 Photosynthesis uses carbon dioxide from respiration and produces oxvqen neededfor respiration3 A point called compensation point has reached whereby all the carbon dioxideproduced during respiration is reused during photosynthesis.

I{EAT

GLLCOSI:t

PI IOI'OS\'\THESIS

i?8

RESPIRATION

8io-KlT l0


13/14

llight intensity

Net sugar production ( ratL.of photosynthesis . rate ofrespiration )

Net sugar loss ( rate of sugarused in respiration , rate ofsugar produce duringphotosynthesis)

high llighl rntensity

The rate of carbon dioxideconsum ption during photosynthesis.

Releasesof CO:inc rc'a sc- s

' Rate of photosvnthesis is higher than the rate ofrespiration' Carbon dioxide is taken in from the atmosphere. Oxvqen is released into the atmosphere. The rate of suqar production is higher than the rate ofsugar consumption' Excess sugar can be used for qroMh and other livingDTOCCSSES

no net gain or net loss in CO2 by plants and nonett gain or net loss in the sugar produced.

Compensation point

The iate of carbon dioxide productiond,uring respiration .

119 Aio-KlT l0


14/14

!

'f

,l

compare and contrast tletween photosynthesis and respiration

RESPIRATION TOSYNTHESISTakes place in all Organisms involve lTakes place only ln qreenorganrsms plantsOccurs during day and nighl Occurs only on dav time or at

certain light intensity.

ProcessAs a anabolisme process, thatis ihe synthesis of complexmolecules from a simplermolecules .

I

Reaction

Exchange ofenergy

Carbon dioxide and r,vater areused while oxygen and glucoseare released.

Light energy ischemical energy

converted to

similaritiesOccurs in organelle of living ceil

When it occursAs a catabolisme process, thalis the metabolisme break downof complex molecules to smallerones.Glucose and oxygen are usedwhile the carbon dioxide andwater are released.

Chemical energy is convertedto chemical energy ATP andheat energy.

lSir

biology module chap 7

Documents