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Biology Revision Year 2 > Muscles > Flashcards

Flashcards in Muscles Deck (21)
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1

describe antagonistic pairs

muscles are in antagonistic pairs in an incompressable skeleton, thet can only pull - in order for a limb to move in both directions there are 2 muscles

2

what is a ligament?

attaches bone to bone

3

what is a tendon?

attaches bones to muscles

4

what does antagonist describe?

relaxing

5

what does agonist describe?

contracting

6

what are the 5 features of skeletal muscle?

lots of mitochondria, long cells called muscle fibres, multitnucleate, contain myofibrils, contain myofilaments (actin and myosin)

7

what region is the sarcomere?

between the z lines

8

what is the A band?

all myosin

9

what is the I band

actin only

10

what is the H zone?

non overlapped myosin

11

describe actin

thin and light

12

decribe myosin

dark and thick

13

in a relaxed muscle what prevents an actinomyosin bridge forming?

tropomyosin

14

what is the role of Ca2+ in muscle contraction?

Ca2+ causes tropomyosin to move out of binding site, allowing actinomyosin bridge to form. Also actrivates ATP ase for the hydrolysis of ATP

15

what is the role of ATP in contracting muscles?

changes the shape of the myosin heads, continues as long as binding site is open, detaches the myosin head and returns to starting position. ATP also needed to reabsorb calcium ions.

16

when a sarcomere contracts…

the H, I and sarcomere get smaller. The A band stays the sAme

17

describe the phosphocreatine reaction.

PCr + ADP ---> ATP + Cr - this reaction is short and quick, reserves used up quickly, anaerobic and alactic
the enzyme creatine kinase removes the phosphate from the PCr, allowing phosphorylation to take place

18

describe anaerobic respiration

glycolysis - 2 ATP made, pyruvate -----> lactate - causes muscle fatigue

19

describe aerobic respiration

lots of ATP made by oxidative phosphorylation, slow, no harmful waste

20

describe fast twitch muscles

contract/relax quickly, high force of contraction, fatigue quickly, anaerobic respiration, few… mitochondria, blood vessels, myoglobin ….. So appear white/ pale

21

describe slow twitch muscles

contract/relax slowly, low force of contraction, resistant to fatigue, respire aerobically, lots of……mitochondria, blood vessels, myoglobin…so appear red/pink