BioWorkbook1A Ans e

8/16/2019 BioWorkbook1A Ans e

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B Designing the set#u

C Collecting data

1 (Answer varies with Ss.)$ 'epeat the e$periment a few more times.

D (isk assess&ent and safety recautions

1 urin" the preparation of jelly solution% the hot water may urn our ody.

The knife used to cut the pineapple is very sharp and may cut our fin"ers.

$ !ear a pair of thick "loves when handlin" hot water.

*andle the knife with care.

Write an e' eri&ental re ort " . 1#)%

*b!ective

To investi"ate the effect of fresh pineapple on the settin" of jelly.

+y othesis

It is the fresh pineapple that causes the jelly to remain in liquid form.

A aratus and &aterials

+ electronic alance

+ refri"erator

, eakers (- cm / )

+ measurin" cylinder (+ cm / )

, plastic containers

, "lass rods

+ knife

fresh pineapple

hot water

jelly powder

Procedure

1 0ut a fresh pineapple into small pieces.

Ox ord !ni"ersity Press #$$%


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$ Add - " of jelly powder and , cm / of hot water to a eaker. Stir the mi$ture with a"lass rod until all the jelly powders dissolve.

, 1our + cm / of jelly solution into two containers respectively. 2eave the jelly solutionsat room temperature for one hour.

) 1ut the small pieces of fresh pineapple into one of the containers. Then% refri"erate twocontainers overni"ht.

- 3 serve any chan"es of jelly solutions in the two containers on the ne$t day.

(esults

The jelly without fresh pineapple set.

The jelly with fresh pineapple does not set.

Analysis and discussion

1 It is used to confirm that the presence of fresh pineapple is the only factor that preventsthe jelly from settin".

$ (Answer varies with the desi"n.)

Conclusion

The presence of fresh pineapple prevents the jelly from settin".



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Ch $ he cell as the basic unit of life

Practical $.1 *bservation with a light &icrosco e

(esults " . $#)%( rawin"s vary with the cells o served. rawin"s of human cheek cells and onion epidermalcells are "iven as e$amples.)

/uestions " . $#)%1 To allow entry of a suita le amount of li"ht. A dim ima"e may result if there is

insufficient li"ht while a faint ima"e may result if the li"ht is too ri"ht.

$ The coarse adjustment kno leads to a lar"er de"ree of movement of the ody tu e.

Any downward movement of the ody tu e controlled y the coarse adjustment knomay dama"e the o jective or the slide ecause the distance etween the o jective and theslide is very small.



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,0ow ower +igh ower

Area of specimeno served (small 4 lar"e)

lar"e small

etails of specimen(more 4 less)

less more

5ri"htness of ima"e( ri"ht 4 dim)

ri"ht dim

) Towards the left. An inverted ima"e is formed in the microscope. It moves in a directionopposite to the actual movement of the flatworm.

Practical $.$ Pre aration of te& orary &ounts of ani&al cells

and tissues

(esults " . $# %

/uestions " . $#2%

1 To flatten the specimen so that they can e seen easily in one plane of focus for theo jective lens. To prevent the o jective lens from "ettin" dirty y touchin" the specimenor the mountin" medium. To prevent the specimen from dryin" out ecause ofevaporation. To protect the specimen from ein" dama"ed.

$ 0ell mem rane% nucleus and cytoplasm.

, Anywhere inside the cell.

) 6o. 4 7es% they have small vacuoles.



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Practical $., Pre aration of te& orary &ounts of lant cells

and tissues

(esults " . $#1$%

/uestions " . $#1,%1 0ell wall% cell mem rane% nucleus% cytoplasm% chloroplast and "ranule.

$ 6ear the side of the cell.

, 6o. 6ot all of them contain chloroplasts or chlorophyll. 3nly those with chloroplasts are"reen.

) Similarities8 5oth of them have a nucleus% a cell mem rane and cytoplasm.

ifferences8

+ 1lant cells are often lar"er than animal cells.

, 1lant cells have a definite shape while the animal cells do not.

/ 1lant cells have a thick cell wall and some have chloroplasts. Animal cells do nothave cell walls or chloroplasts.

9 1lant cells usually have a lar"e vacuole while animal cells do not.



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Practical $.) 3'a&ination of rokaryotic and eukaryotic cells

(esults " . $#1-%Prokaryotic cell 3ukaryotic cell

Si&e:sually smaller :sually lar"er

;enetic material6A lyin" free in thecytoplasm

6A enclosed in the nucleus

6uclear mem raneA sent 1resent

3r"anelles ounded y a dou le mem rane(e.". mitochondria)

A sent 1resent


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Ch , 5ove&ent of substances across cell &e&brane

Practical ,.1 De&onstration of os&osis using dialysis tubing

(esults " . , #$%Set#u Change in li6uid level in the ca illary tube


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/uestions " . , #4%1 Set up 5 is a control. It shows that any chan"e in liquid level in set up A is due to the

concentrated sucrose solution.

$ istilled water has a hi"her water potential than concentrated sucrose solution% so thereis a net movement of water from the distilled water to concentrated sucrose solutionthrou"h the differentially permea le animal tissues y osmosis. The volume of liquidinside the thistle funnel increases and the liquid level rises.

Conclusion " . , # %2ivin" animal tissues are differentially permea le. !hen solutions with different water

potential are separated y livin" animal tissues% osmosis takes place.

Practical ,., Study of os&osis in red blood cells

(esults " . , #7%Concentration of

sodiu& chloride solutionA earance of the red blood cells

B any red lood cells swell and urst.

.9-B Cew red lood cells swell and urst.

.DB 'ed lood cells are normal.

+./-B Cew red lood cells shrink and ecome wrinkled.

+.EB any red lood cells shrink and ecome wrinkled.

/uestions " . , #7%1 .DB sodium chloride solution is isotonic to the red lood cells. At this concentration%

the red lood cells appear normal. It shows that there is no net movement of water into or out of the cells ecause there is no difference in water potential etween the cells and itssurroundin".

$ B and .9-B sodium chloride solutions are hypotonic to the red lood cells. At theseconcentrations% the red lood cells swell and urst. It shows that the water potential ofthe red lood cells is lower than that of the sodium chloride solution. !ater enters the red

lood cells y osmosis.



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, 6o. This is ecause the concentration of the content 4 water potential of each cell varies.

Conclusion " . , #1,%!hen the surroundin" fluid has a lower water potential than the plant cells% water leaves the

cells y osmosis. The cells finally ecome plasmoly&ed and flaccid. !hen the water potentialof the surroundin" fluid increases% water will enter the cells y osmosis. The cytoplasme$pands and the cells ecome tur"id.

Practical ,.- Study of os&osis in living lant tissue

(esults " . , #1-%0i6uid

inside thebeaker

Initial weight (") 9inal weight (") Percentage

change inweight (B)

Stri1

Stri$

Stri,

Average Stri1

Stri$

Stri,

Average

istilled!ater

,.E+ ,.F> ,.E ,.FD /. E /.+- /. F /.+ ++.++B

+ Bsucrosesolution

,.F> ,.EF ,.E/ ,.E, ,.FD ,.E ,.E+ ,.E .F+B

, Bsucrosesolution

,.E9 ,.E/ ,.E- ,.E9 ,.-F ,.>, ,.-- ,.-E D.+-B

/uestions " . , #14%1 3smosis cannot takes place across the potato peel ecause the peel is impermea le to

water. Any peel left on the potato strips will affect the result.

$ To prevent the evaporation of water which may chan"e the concentration of the liquids inthe set ups and affect the results.

, To a sor the surplus water on the surface of the potato strips which may increase thewei"ht of the potato strips and affect the results.

) To minimi&e the water loss from the potato strips y evaporation. Any water loss willdecrease the wei"ht of the potato strips and affect the results.



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- The potato strips in distilled water ecome heavier. This is ecause the water potential of distilled water is hi"her than that of the potato cells. !ater enters the potato strips yosmosis.

4 The wei"ht of the potato strips in + B sucrose solution chan"es very sli"htly. This is ecause the water potential of + B sucrose solution is nearly the same as that of the potato cells. There is almost no net movement of water into or out of the potato strips.

The potato strips in , B sucrose solution ecome li"hter. This is ecause the water potential of , B sucrose solution is lower than that of the potato cells. !ater leaves the potato strips y osmosis.

Conclusion " . , #1 %2ivin" plant tissues are differentially permea le. !hen livin" plant tissues are placed insolutions with different water potential% osmosis takes place.



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Practical ,.4 3'a&ination of hagocytosis in Amoeba

(esults " . , #17%

/uestions " . , #17%1 Amoeba takes in food particles y pha"ocytosis8 when Amoeba "ets close to the food

particles% pseudopodium starts to form to surround the food particles. The whole food particles are finally en"ulfed y the Amoeba .

$ 1ha"ocytosis is important for8

+ the nutrition of some sin"le celled or"anisms% e.". Amoeba en"ulfs food particles y pha"ocytosisG

, ody defence a"ainst diseases% e.". in humans and other mammals% certain white lood cells en"ulf harmful microor"anisms y pha"ocytosis.



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Ch ) 3n:y&es and &etabolis&

Practical ).1 De&onstration of the breaking#down action of

en:y&es

(esults " . ) #,%Sa& le ;lowing s lint relights

hydro"en pero$ide H liver e$tract H

distilled water H liver e$tract –

hydro"en pero$ide H distilled water –

/uestions " . ) #,%1 This increases the surface area for reactions.

$ ;rindin" action produces heat. The hi"h temperature resulted may denature any en&yme present in the tissues.

, The "as "iven off is o$y"en.

) a It is a control to show that no o$y"en is "iven off from the liver e$tract.

b It is a control to show that no o$y"en is "iven off from the hydro"en pero$ide.

- 2iver e$tract reacts with hydro"en pero$ide to produce o$y"en.

4 6o. This e$periment only shows that the reakdown of hydro"en pero$ide is speeded up y the liver e$tract. 5oiled liver e$tract% instead of fresh liver e$tract% can e used in afurther e$periment. If oiled liver e$tract has no catalytic action% it is more likely that thereaction is catalysed y an en&yme.

7es. Cor the three test tu es% only one varia le (the sample) is chan"ed at a time% othervaria les (e.". the volume and temperature of hydro"en pero$ide% liver e$tract anddistilled water) are kept constant.

Conclusion " . ) #)%

The reakdown of hydro"en pero$ide is catalysed y the liver e$tract% pro a ly y an en&ymein the liver tissues. 6evertheless% further e$periments should e done to confirm this.



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Practical ).$ Investigation of the effect of te& erature on

en:y&e activity

(esults " . ) # %e& erature ( 0) i&e for disa earance of blue#black colour (min)

The lue lack colour does not disappear.

,

9 ('esults vary with the ori"in of amylase.)

>

E

+ The lue lack colour does not disappear.

/uestions " . ) # %1 To ensure that the amylase and starch solutions inside the tu es reach the respective

temperatures efore the reaction starts.

$ To prevent the chan"in" of the condition of a mi$ture y any residue in the dropper.

, Amylase is inactive at low temperatures. Its activity increases with temperature and isthe hi"hest at > 0. Afterwards the activity decreases and stops at + 0. !ith a rise intemperature% the kinetic ener"y of amylase and starch molecules increases. They collideand react more frequently. As the temperature increases further% the active sites ofamylase ecome distorted (i.e. the en&yme is denatured) and the reaction rate decreases.At + 0% all amylase is denatured and no reaction takes place.

) a Starch will e di"ested and lue lack colour will disappear. This is ecause theinactive amylase will resume its activity with an increase in temperature.

b Starch will not e di"ested and lue lack colour will remain. This is ecause theactivity of the denatured amylase will not restore even when it is cooled.

- easurin" the rate of appearance of maltose molecules.

Conclusion " . ) #2%Amylase is inactive at low temperatures. Its activity increases with temperature until itreaches a ma$imum. Afterwards the activity decreases and stops.



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Practical )., Investigation of the effect of + on en:y&e

activity

Results " . ) #18%

ube + De th of brick#red reci itate settled(mm)

A /.,

5 9.

0 -., ('esults vary with the ori"in of invertase.)

>.

< F.

C E.

Questions " . ) #11%

1 To ensure the invertase has sufficient time to catalyse the reakdown of sucrose into"lucose and fructose.

$ (Answer depends on results.)

, a 6o or less rick red precipitate will e formed. This is ecause e$tremely low p*will denature the invertase and reduce the en&yme activity.

b 6o or less rick red precipitate will e formed. This is ecause e$tremely hi"h p*will denature the invertase and reduce the en&yme activity.

) !ei"hin" the precipitate formed. 4 :sin" an ar itrary system of HK to denote the relativeamount of precipitate.

Conclusion " . ) #11%

Invertase is most active in the acidic medium (p* -.,) and less active in the neutral andalkaline medium.



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Practical ).) Investigation of the effect of inhibitors on en:y&e

activity

Results " . ) #1,%

ube Sa& le thatcontains

De th of brick#red reci itate settled(mm)

A copper(II) sulphatesolution

5 silver nitrate solution (Answer varies with Ss.)

0 distilled water

Questions " . ) #1)%

1 It is a control to show that the activity of invertase is slowed down or stopped y theinhi itor.

$ 6o or less rick red precipitate is formed in tu es A and 5 ecause copper(II) ions andsilver ions are inhi itors of invertase. They slow down or stop the activity of invertase.

5rick red precipitate is formed in tu e 0 ecause the activity of invertase is not affected y any inhi itor.

, !hether an inhi itor is competitive or non competitive can e found out y increasin"the su strate concentration of the reaction medium. The reaction rate will e increased incase of competitive inhi ition% ut not in case of non competitive inhi ition.

Conclusion " . ) #1)%0opper(II) ions and silver ions are inhi itors of invertase. They slow down or stop the activityof invertase.



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Practical ).- Investigation of rotease activities in different

fruit !uices

Results " . ) #1 %

Well Sa& le Dia&eter of clear :one(num er of squares on "raph paper)

A 1ineapple juice

5 Liwi fruit juice

0 1apaya juice ('esults vary with Ss.)

;uava juice

< istilled water

Questions " . ) #1 %

1 It is a control to show that the formation of the clear &ones is due to the fruit juices.

$ 1roteases in the fruit juices reak down the white milk protein near y. Therefore% thewhite colour of the milk disappears and the clear colour of the a"ar is shown around thewells containin" fruit juices.

, (Answer depends on results.)

) It is ecause the proteases in pineapple are denatured y the hi"h temperature durin" thecannin" process.

- The proteases in fresh pineapple can reak down the proteins in eef steak. 2eavin" eefsteak in contact with slices of pineapple for half an hour allows enou"h time for theen&ymes to work.

Conclusion " . ) #12%

1ineapple% kiwi fruit% papaya and "uava contain proteases that can reak down proteins% ut

their activities differ from one another.



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Write an experimental report " . ) #$$%

*b!ective

(Answer varies with Ss.)



Procedure

Ss can carry out the e$periment in a num er of ways.Ss may conduct the e$periment y usin" a milk a"ar plate (see 1ractical 9.-).Another method is usin" two test tu es containin" equal volumes of oiled e"" white cu es.Add the two washin" powder solutions into the test tu es and compare the rate of dissolvin"

of the e"" white cu es.

(esults



1 (Answer depends on results.)

$ 6o. !e should consider the price of each rand.

, It is ecause en&yme activity increases at a hi"her temperature.

) It is ecause proteins in silk and wool will e roken down y the proteases.- (Answer varies with the desi"n.)

Conclusion




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3 est for roteins using Albusti' a er

Sa& le Albusti' a er

*riginal colour 9inal colour


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4 a 5oilin" destroys the reducin" property of vitamin 0. Thus% only the vitamin 0solution that has not een oiled can reduce the lue 01I1 solution anddecolouri&e it.

b o not oil or overheat fruits and ve"eta les.

6o. ;lucose% like vitamin 0% is reducin" and will decolouri&e 01I1 solution no mattervitamin 0 is present in the sample or not.

Practical -.$ Investigation of the food substances in co&&on

foodstuffs

Results " . - #1$%

9oodsa& le

;lucose (educingsugars

Starch 0i ids Proteins >ita&in C

Question " . - #1$%

(Answer depends on the types of foods tested.)

Practical -., Design an investigation to co& are the a&ount of

vita&in C in different fruits and vegetables

Design and perform a fair test " . - #1)%

1 7es. Accurate measurement is necessary ecause a comparison of vitamin 0 content indifferent fruits and ve"eta les is needed.


('esults vary with the types of foods tested.)


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$ Cruits or ve"eta les that have juices very pale in colour. The pale colour of the juices willnot mask the decolouri&ation of 01I1 solution.



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A Identifying variables

Inde endent variable(!hat will you chan"e#)

De endent variable(!hat will you measure#)

Controlled variables(!hat will you keep

constant#)

The type of fruits andve"eta les.

The num er of drops ofsample needed todecolouri&e + cm / of 01I1solution.

Amount of each type offruits and ve"eta les used toe$tract the juices% volumeand concentration of 01I1solution used with eachsample% temperature ofsample and 01I1 solution%etc.



C Collecting data

1 (Answer varies with Ss.)

$ :se less 01I1 solution or a more dilute 01I1 solution., Take any dilution factor of the juices into consideration in the comparison of vitamin 0

content.

'epeat the e$periment with more samples from the same types of fruits and ve"eta les.


1 The knife used to cut fruits and ve"eta les is very sharp and may cut our fin"ers.

$ *andle the knife with care.

Write an experimental report " . - #14%

*b!ective

To compare the vitamin 0 content in different fruits and ve"eta les.



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+ test tu es+ test tu e rack + droppers

+ measurin" cylinder (+ cm / )+ mortar and pestle+ knife

+ filter funnelfilter paper or fine muslin. ,B 01I1 solution

distilled water fruits and ve"eta les (e.". oran"e% lemon%ca a"e)

Procedure

1 0ut the fruit or ve"eta le into small pieces.

$ 1ut the small pieces into a mortar and "rind with a small known quantity of cooldistilled water (if necessary) usin" the pestle.

, Squee&e the "round materials throu"h several layers of pre moistened fine muslin or

filter them throu"h a filter paper to remove the de ris. 0ollect the juice e$tracted.Skip this step if a fine and fairly colourless suspension is o tained.

) 1ut + cm / of 01I1 solution in a test tu e.

- :se a dropper to add the juice% drop y drop% to the01I1 solution until the solution is decolouri&ed.'ecord the num er of drops of juice added.

4 'epeat steps 9 and - with the juices e$tracted from different fruits and ve"eta les. If thedecolouri&ation is too quick (i.e. the juice is too concentrated)% dilute the juice y aknown volume of distilled water and repeat steps 9 and - a"ain. Take this dilution factor into consideration in the comparison of vitamin 0 content.

'epeat steps 9 and - with distilled water. It is a control.

(esults

Sample 6um er of drops of sample needed to decolouri&e+ cm / of 01I1 solution

2emon +-3ran"e +,0a a"e +Distilled water 0annot decolouri&e 01I1 solution


1 (Answer depends on the results.)



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$ (Answer depends on the results.)

, 'educin" property.

) a The vitamin 0 content will decrease as vitamin 0 will e o$idi&ed y the air.

b The vitamin 0 content will decrease as vitamin 0 will e destroyed y hi"htemperatures.

- The vitamin 0 in the juices will e o$idi&ed y the air.

The o servation of complete decolouri&ation of 01I1 solution is su jective% especiallywhen the juices are coloured.

There are other reducin" su stances% e.". "lucose and fructose% in the juices.

4 Cruits or ve"eta les that have juices very dark in colour cannot e used. The dark colourof the juices masks the decolouri&ation of 01I1 solution.

Conclusion

(Answer depends on the results.)



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4 ?utrition in hu&ans

Practical 4.1 3'a&ination of the &a&&alian ali&entary canal

and its associated glands

Questions " . 4#$%

1A outh 5 3esopha"us

0 Stomach uodenum

< 1ancreas C Appendi$

; Ileum * 0aecum

I 2iver J 0olon

L 'ectum 2 Anus

$ A 5 0 ;

J L 2

,Structure ?utrition rocess involved

A In"estion% di"estion

0 i"estion

i"estion% a sorption

; i"estion% a sorption

2


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$ /F 0. To simulate the ody temperature at which pepsin works well.



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A Identifying variables

Inde endentvariable

(!hat will you

chan"e#)

De endent variable(!hat will you

measure#)

Controlledvariables

(!hat will you keep

constant#)

Control(!hat is the controlin this e$periment#)

The solutions in thetest tu es.

The disappearanceof e"" white cu es.

6um er and si&e ofe"" white cu es%temperature and totalvolume of solution%etc.

A test tu e with ane"" white cu e%hydrochloric acidand distilled water. Atest tu e with an e""white cu e% sodiumcar onate solutionand distilled water. A

test tu e with an e""white cu e anddistilled water.



C Collecting data

1 (Answer varies with Ss.)

$ 1rovide a hi"her temperature% use smaller e"" white cu es instead of a lar"e one% raisethe e"" white cu e from the ottom of the test tu e y usin" a toothpick% etc.

, 'epeat the e$periment a few more times.


1 The knife used to cut the hard oiled e"" is very sharp and may cut our fin"ers.

ilute hydrochloric acid is corrosive and dilute sodium car onate solution is irritant.

$ *andle the knife with care. !ear disposa le "loves. !ash hands thorou"hly with liquidsoap and water after the e$periment.

Write an experimental report " . 4#4%

*b!ective

To investi"ate the action of pepsin in protein di"estion.



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> test tu es+ test tu e rack + measurin" cylinder (+ cm / )

+ knife+ water ath

dilute hydrochloric aciddilute sodium car onate solutiondistilled water

pepsin solution+ hard oiled e""

Procedure

1 0ut the e"" white of the hard oiled e"" into si$ small cu es of len"th .- cm and putone in each of the si$ test tu es.

$ Add the followin" solutions to the test tu es.

est tube SolutionA - cm / pepsin solution H - cm / dilute hydrochloric acid

5 - cm / pepsin solution H - cm / dilute sodium car onate solution0 - cm / pepsin solution H - cm / distilled water

- cm / hydrochloric acid H - cm / distilled water < - cm / sodium car onate solution H - cm / distilled water C + cm / distilled water

, 2eave the test tu es in a water ath at /F 0 overni"ht.

) 3 serve and note any chan"es in the si&e and appearance of the e"" white cu e in eachtest tu e.

(esults

est tube *bservationA The e"" white cu e disappears.5 The e"" white cu e remains intact.0 The e"" white cu e remains intact.

The e"" white cu e remains intact.< The e"" white cu e remains intact.C The e"" white cu e remains intact.

Analysis and discussion1 Stomach.

$ 1rotease.

, 1eptides.

) 1ositive. 1epsin is a protein and it chan"es the colour of the Al usti$ paper.

- (Answer varies with the desi"n.)

Conclusion

1epsin di"ests proteins in an acidic medium.



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Practical 4., De&onstration of the effect of bile salts on oil

Results " . 4#18%

5i'ture of oil and bile saltsolution

5i'ture of oil and distilledwater

A earance An emulsion is formed. Two layers of liquids can eseen8 oil on the top and water at the ottom. The twoliquids do not mi$.

Question " . 4#18%

!ater cannot reak down oil into small droplets as the ile salt solution does. Therefore% noemulsion is formed and two layers of liquids can e seen.

Conclusion " . 4#18%

5ile salts can reak down lipids into small droplets. It is an emulsifyin" a"ent.

Practical 4.) Si&ulation of digestion and absor tion in the

s&all intestine using dialysis tubing

(esults " . 4#1$%Starch (educing sugars

At start – –

After one hour – H

/uestions " . 4#1$%1 Starch solution on the outside of the tu in" will affect the result. !ashin" the tu in"

ensures no such starch solution is present.

$ 2ess water allows a hi"her concentration of starch or reducin" su"ar molecules for easydetection.



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,Part of the &odel Part of the hu&an body

ialysis tu in" !all of the small intestine

!ater surroundin" the tu in" 5lood

Starch and amylase mi$ture inthe tu in"

i$ture of undi"ested food and di"estive en&ymes in thesmall intestine

) a 'educin" su"ar (maltose) is found.

b Amylase di"ests starch into maltose. altose molecules are small enou"h to passthrou"h the tu in" and diffuse into the water outside the tu in"% whereas the lar"estarch molecules are retained inside the tu in".

- Throu"h di"estion% food su stances are roken down into small molecules that candiffuse throu"h the intestinal wall 4 epithelium into the lood for use in our ody.

4 altose molecules are not small enou"h to pass throu"h the small intestine.

The small intestine can a sor di"ested food y active transport ut the dialysis tu in"cannot.

The small intestine can secrete en&ymes ut the model cannot.

The small intestine shows peristalsis ut the model does not.

There are many types of food molecules in the small intestine apart from starch.

The food molecules have to pass throu"h more than one layer of cells instead of only onelayer of tu in".

The lood is enclosed in lood vessels.

iffusion rate of the reducin" su"ar molecules can e increased y stirrin" thesurroundin" water and usin" a water ath at a hi"her temperature.

ore concentrated solutions of starch and amylase can e used to speed up the reaction

rate.

BioWorkbook1A Ans e

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