Muscles Revision Questions

8/9/2019 Muscles Revision Questions

1/20

1. The diagram represents actin and myosin in a muscle cell.

O f f

O n

M y o s i n

M y o s i n h e a d

S w i t c h p r o t e i n( t r o p o m y o s i n )

B i n d i n g s i t e o na c t i n m o l e c u l e

A c t i n

(a) With reference to the diagram:

(i) descrie the part played y calcium ions in muscle contraction!

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................(2)

Cranford Community College 1


2/20

(ii) e"plain how the muscle cell contracts.

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

(2)

() #escrie how AT$ is used in muscle contraction.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(1)

(Total 5 marks)

2. Muscles contract when some of their cells ecome shorter in length. This shortening is rought

aout when myosin and actin filaments in the cytoplasm of muscle cells slide o%er each other.

&"plain how AT$ and calcium ions ('a) help the myosin and actin filaments to slide o%er eachother during the shortening of a muscle cell.

AT$ ......................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................(2)

'a .......................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................

...............................................................................................................................................(2)

(Total 4 marks)



3/20

3. The diagram shows the appearance of part of a myofiril from a s*eletal muscle fire when

%iewed with a light microscope.

+, o n e

-

a n d

A a n d

a n d

(a) The muscle fire is rela"ed. When the muscle contracts/ what happens to the appearanceof:

(i) the A and!.......................................................................................................

(ii) the and!.........................................................................................................

(iii) the + ,one0.......................................................................................................(2)

() n which of the regions laelled in the diagram would the following e present0

(i) Myosin.............................................................................................................

(ii) Actin.................................................................................................................(2)

(c) #escrie the role of calcium ions in muscle contraction.

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................(2)

(Total 6 marks)



4/20

4. S*eletal muscle is made of undles of fires.

(a) #escrie the roles of calcium ions/ AT$ and phosphocreatine in producing contraction of

a muscle fire.

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................(4)

S () The tale shows some properties of slow and fast muscle fires.

Property of fibre Type I (slow fibres) Type II (fat fibres)

1umer of mitochondria per fire Many 2ew

'oncentration of en,ymes

regulating glycolysis

Moderate +igh

3esistance to fatigue +igh 4ow



5/20

&ndurance athletes/ such as marathon runners/ nearly always ha%e a high proportion of

slow fires in their muscles. &"plain the enefit of this.

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................(6)

(c) #uring e"ercise/ much heat is generated. #escrie the homeostatic mechanisms that

restore normal ody temperature following %igorous e"ercise.

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................

....................................................................................................................................(5)

(Total 15 marks)



6/20

5. The diagram shows the arrangement of some of the proteins in a myofiril from a s*eletal

muscle. The myofiril is shown in the rela"ed state.

5 l i n e

A a n d . a n d

+ , o n e

S a r c o m e r e

(a) 1ame the protein found in the + ,one.

.....................................................................................................................................(1)

() When the muscle contracts/ what happens to the width of

(i) the A and! .......................................................................................................

(ii) the and0 ........................................................................................................(2)



7/20

S (c) The distance etween two 5 lines in a myofiril is 6.7 m. 'alculate the magnification of

the diagram. Show your wor*ing.

Answer ........................................................................................................................(2)

(Total 5 marks)

6. (a) Figre 1 shows part of a myofiril from s*eletal muscle.

5 l i n e 5 l i n e5 l i n e

T h i c * f i l a m e n t T h i n f i l a m e n t

A a n d A a n d

S a r c o m e r e S a r c o m e r e

Figre 1



8/20

(i) #escrie two features/ %isile in the diagram/ which show that the myofiril is

contracted.

6 .........................................................................................................................

............................................................................................................................

..............................................................................8........................................

............................................................................................................................(2)

(ii) &"plain the role of calcium ions and AT$ in ringing aout contraction of a muscle

fire.

'alcium ions ..............................................................................................88

............................................................................................................................

............................................................................................................................

AT$ ....................................................................................................................

............................................................................................................................

............................................................................................................................(3)



9/20

() Figre 2shows the structure of a neuromuscular 9unction. The %esicles contain

acetylcholine.

M o t o rn e u r o n e

$ r e s y n a p t i cm e m r a n e

S y n a p t i cc l e f t

M e m r a n e o f m u s c l e f i r e

: e s i c l e s

Figre 2

(i) An action potential is generated at the cell ody of the motor neurone.

&"plain how this action potential passes along the motor neurone to the

neuromuscular 9unction.

............................................................................................................................

............................................................................................................................

............................................................................................................................

............................................................................................................................

............................................................................................................................

............................................................................................................................

(3)



10/20

(ii) When the action potential arri%es at the neuromuscular 9unction/ it results in the

secretion of acetylcholine into the synaptic cleft. &"plain how.

............................................................................................................................

............................................................................................................................

............................................................................................................................

............................................................................................................................

............................................................................................................................

............................................................................................................................(3)

(c) Between the ages of ; and ;. Assume that the rate of muscle loss in each age

range is constant.

(3)

(ii) &"plain why e"plosi%e e"ercises/ such as sprinting and weightlifting/ will e more



11/20

affected y this muscle loss than aeroic e"ercises/ such as 9ogging.

............................................................................................................................

............................................................................................................................(1)

(Total 15 marks)

!. Figre 1 shows part of a single myofiril from a s*eletal muscle fire as it appears under an

optical microscope.

5 @ l i n e 5 @ l i n e

5 @ l i n e5 @ l i n e

F i g r e 1

Figre 2

(a) (i) 'omplete Figre 2 to show the arrangement of actin and myosin filaments in thispart of the myofiril as they would appear under an electron microscope.

4ael the actin and myosin filaments.(2)



12/20

(ii) Why are the details you ha%e drawn in Figre 2 %isile under the electron

microscope ut not under the optical microscope0

...........................................................................................................................

...........................................................................................................................(1)

() The myofiril in Figre 1 is magnified >;;;. A muscle fire is ?; m in diameter.

'alculate the numer of myofirils which would fit side y side across the diameter of

the muscle fire. Show your wor*ing.

Answer .............................................. myofirils.(2)

(Total 5 marks)

". The diagram shows part of a myofiril from a rela"ed muscle fire.

A a n d a n d + , o n e

6 . ; m

5 l i n e



13/20

(a) When the muscle fire contracts/ which of the A and/ and and + ,one

(i) remain unchanged in length/ ....................................................................................(1)

(ii) decrease in length0 ...................................................................................................(1)

() &"plain what caused the decrease in length in part (a)(ii).

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(2)

(c) The whole muscle fire is C; mm long when rela"ed. &ach sarcomere is .< m long

when contracted. Dse the scale gi%en on the diagram to calculate the length of the

contracted muscle fire in millimetres.

4ength of contracted fire E ...................................... mm(2)

(d) The tale gi%es some properties of the two different types of muscle fire found in

s*eletal muscle.

(i) 'omplete the tale y writing the words FhighG or FlowG for the remaining three

properties of each type of muscle fire.

Type of ms#le fibre

Type 1 Type 2

Speed of contraction high low

2orce generated high low

Acti%ity of the en,ymes of glycolysis high low

1umer of mitochondria

Acti%ity of Hres cycle en,ymes

3ate of fatigue

(3)



14/20

(ii) The myosin@AT$ase of type 1 muscle fires has a faster rate of reaction than that in

type 2 fires. Dse your *nowledge of the mechanism of muscle contraction to

e"plain how this will help type 1 muscle fires to contract faster than type 2.

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................(4)

S (iii) The lood lea%ing an acti%e muscle with a high percentage of type 1 muscle fires

contained a higher concentration of lactate than that lea%ing a muscle with a high

percentage of type 2 muscle fires. &"plain why.

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................(2)

(Total 15 marks)



15/20

$. The flow chart outlines an in%estigation to determine from where the calcium ions in%ol%ed in

muscle contraction are released.

'alcium ion transport proteins were

isolated from human tissue.

These proteins were in9ected into a rait.

The rait formed antiodies to the

proteins. These antiodies were collected

and laelled with gold particles.

Muscle tissue was treated with the

laelled antiodies and e"amined with an

electron microscope. +igh concentrations

of gold particles were oser%ed attached

to the sarcoplasmic reticulum.

S (a) 4aelled antiodies and an electron microscope can e used to produce images locating

proteins on the surface of organelles/ ut cannot e used to oser%e cross ridge cycling

in muscle cells. &"plain why.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(5)



16/20

() #escrie the role of calcium ions and AT$ in muscle contraction.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(5)

(Total 1% marks)



17/20

1%. The diagram shows four stages in the cycle of actinImyosin cross ridge formation which

results in contraction of a muscle.

S t a g e &

S t a g e '

S t a g e (

S t a g e )

+ e a d o f m y o s i nm o l e c u l e a t t a c h e dt o a c t i n

A c t i n f i l a m e n t / m a d eu p o f a c t i n m o l e c u l e s9 o i n e d t o g e t h e r

*

+

A T $

(a) 1ame molecule * and ion +.

* ..........................................................

+ ..........................................................(1)



18/20

() Dse the information in the diagram to e"plain how actin mo%es past myosin. n your

answer/ refer to the stages &/ '/ and . (A description of the roles of calcium ions and

tropomysin is not reJuired.)

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(4)

(c) After an animal dies/ respiration stops and no more AT$ is made. The muscles ecome

rigid and fi"ed in their length. Dse the information in the diagram to suggest an

e"planation for this.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(1)

(Total 6 marks)



19/20

11. The diagram shows the stages in one cycle that results in mo%ement of an actin filament in a

muscle sarcomere.

M y o s i n h e a dF r e c o c * s G

u s i n g e n e r g yf r o m A T $

M y o s i n

A c t i n

A T $ i n d sM y o s i n h e a dr o t a t e s

M y o s i nh e a d i n d s

M y o s i n h e a dd e t a c h e s

(a) #escrie how stimulation of a muscle y a ner%e impulse starts the cycle shown in thediagram.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(3)



20/20

() &ach cycle reJuires hydrolysis of one molecule of AT$ and mo%es one actin filament

?; nm. #uring contraction of a muscle sarcomere/ a single actin filament mo%es ;.7 m.

'alculate how many molecules of AT$ are reJuired to produce this mo%ement.

Answer ................................................................(2)

(c) After death/ cross ridges etween actin and myosin remain firmly ound resulting in

rigor mortis. Dsing information in the diagram/ e"plain what causes the cross ridges to

remain firmly ound.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(2)

(Total ! marks)

Documents

Muscles Revision Questions