run for your life

Question 1

skeletal muscle

Answer 1

the type of muscle you use to move

Question 2

tendons

Answer 2

attach muscle to bone

Question 3

ligaments

Answer 3

attach bones together

Question 4

antagonistic pairs

Answer 4

muscles that work together to move a bone. one relaxes as one contracts. they create opposite forces

Question 5

flexor

Answer 5

muscle that bends a joint when it contracts

Question 6

extensor

Answer 6

muscle that straightens a joint when it contracts

Question 7

what happens when calcium ions bind to troponin

Answer 7

troponin changes shape
tropomysoin is moved by troponin
myosin binding sites on actin are exposed
(myosin head binds, forming actin-myosin cross bridge)

Question 8

explain how myosin binding sites being exposed leads to muscle contraction

Answer 8

myosin heads can bind to binding sites, forming actin-myosin bridges
actin filaments slide over myosin
therefore sarcomeres shorten
calcium ions activate ATPase which hydrolyse ATP so ADP and inorganic phosphate are released
(ATP provides energy to move myosin head. then, energy breaks actin-myosin cross bridge so myosin head detaches from actin after it has moved
mysoin head then detaches to another binding site further along the actin myofilament)

Question 9

describe interaction between troponin and tropomyosin that allow muscle contraction

Answer 9

troponin changes shape causing tropomyosin to move away from the myosin-binding sites

Question 10

importance of primary sturtucre for functioning of ATPase (in muscle contraction)

Answer 10

primarys tructure determines interaction between R groups
primary sturcture determines tertiary sturcture
therefore affecting shape of active site
active site is complementary to ATP

Question 11

describe how concentration of calcium ions around myofibrils is controlled

Answer 11

calcium ions are released from sarcoplasmic reticulum
in response to action potential/depolarisation
calcium channels open to allow calcium ions to enter the sarcoplasm
calcium ions taken back up by active transport into sarcoplasmic reticulum
troponin returns to its original shape

Question 12

Explain how the extensor and flexor muscles bring about movement of the lower leg.

Answer 12

tendons attach muslces to bones
flexor and extensor muscles act as an antagonistic pair
when extensor muscle contracts, it pulls on the front one to extend the leg
when the flexor muscle contracts, it pulls on the back one flexing the leg

Question 13

how do athletes with amputations are able to move their prosthetic limbs
during a race.

Answer 13

muslces are still attached to the lower leg and prosthetic limb is attached to lower leg

Question 14

Describe two structural differences between fast twitch muscle fibres and slow twitch
muscle fibres.

Answer 14

fast twitch fibres have no mitochondria while slow twitch have many
fast twitch fibres have no capillaries while slow twitch have many

Question 15

Explain how the structure of a muscle fibre is related to its specialised function.

Answer 15

it has myofibrils
myofibrils allow contraction of muscle
many mitochondria to supply ATP for aerobic respiration
sarcolemma contains voltage gated channels to allow depolarisation of muscle fibre
(T tubules to allow depolarisation to be transferred to sarcoplasmic reticulum, which stores and releases calcium ions)

Question 16

what is meant by no significant difference at 0.05 probability level

Answer 16

more than 5%/less than 95% likelihood
calculated value is less than critical value

Question 17

Describe how the tertiary structure of myosin is related to its function.

Answer 17

myosin is folded into a specific shape with a globular head
that can bind to actin
myosin has a site that can bind with ATP
straight to form a bundle with other myosin molecules

Question 18

why does force produced from mass increase then remain constant

Answer 18

increases because myosin binding sites are exposed
remains constant because all actin and myosin are interacting/all myosin binding sites are occupied

Question 19

sarcolemma

Answer 19

cell membrane of muscle fibres

Question 20

sarcoplasm

Answer 20

muscle cell’s cytoplasm

Question 21

T tubules

Answer 21

folds

Question 22

sarcoplasmic reticulum

Answer 22

network of internal membranes

Question 23

how are myofirbils when resting

Answer 23

actin-myosin binding site is blocked by tropomyosin, which is held in place by troponin
actin and myosin can’t slide past each other because myosin heads can’t bind to actin-myosin binding site on actin filaments

Question 24

difference between slow and fast twitch

Answer 24

slow twitch contract slowly, used for posture (back) and endurance, like long distance. it doesn’t get tired for a long time and does aerobic respiration. lots of mitochondira to supply muscles with oxygen. red because many myoglobin - protein that stores oxygen.
fast twitch contract quickly. used for fast movement (eyes and legs) and sprinting. get tired very quickly and arobic respiration releases energy through glycogen. few mitochondira and few myoglobin so white

Question 25

Importance of outer mitochondrial membrane being impermeable to hydrogen ions

Answer 25

Stops H+ diffusing out of cytoplasm Maintaining high concentration of H+ in inter membrane space Protons can move down electrochemical gradient By chemiosmosis To synthesise ATP

Question 26

how to determine safe dose of a drug

Answer 26

test drug on healthy individuals test on group of individuals with condition gradually increase dose

Question 27

How does lactate fermentation work in animals

Answer 27

Glucose is converted to Peru are via glycolysis Reduced NAD transfers hydrogen to pyruvate to form lactate and NAD Production of lactate regenerates NAD so if can be reused in glycolysis, and ATP can still be produced

Question 28

How is lactic acid broken down

Answer 28

Cells convert lactic acid back to pyruvate, which enters Krebs cycle Liver cells convert lactic acid back to glucose, which can be respired or stored

Question 29

Myogenic meaning

Answer 29

Can contract and relax without recovering signals from neurones

Question 30

Heartbeat process

Answer 30

SAN sends out waves of electrical activity Walls of right and left atria contact Waves of electrical activity transferred from SAN to AVN Slight delay before AVN reacts, to make sure ventricles contract after atria empties AVN passes waves of electrical activity to bundle of His Purkyne fibres cause right and left ventricles to contract

Question 31

Explain how rate of breathing is controlled

Answer 31

Inspiratory centre in medulla sends nerve impulses to intercostal muscles and diaphragm to contract Increases volume of lungs and lowers prsssure Air enters lungs so they inflate Stretch receptors are stimulated so nerve impulses sent back to medulla Inhibit action of inspiratory centre Expiratory centre sends nerve impulses to diaphragm and intercostal muscles to relax so lungs deflate and stretch receptors are now inactive

Question 32

How does excercise increase breathing rate

Answer 32

initiates impulses from strecth receptors in muscles increased CO2 increases causes pH in blood to decrease Chemoreceptors detect decrease in blood pH Chemoreceptors send nerve impulses to medulla, which sends more frequent nerve impulses to intercostal muscles and diaphragm This increases rate AND depth of breathing Gaseous exchange speed up

Question 33

Cardiac output

Answer 33

Cardiac output = heart rate x stroke volume

Question 34

Tidal volume

Answer 34

Volume of air in each breath

Question 35

Ventilation rate

Answer 35

Ventilation rate = tidal volume x breathing rate

Question 36

Explain why it is necessary for the cardiac output of marathon runners to increase during a race.

Answer 36

increase supply of oxygenated blood to allow aerobic respiration to provide energy

Question 37

Explain the effect of exercise on the changes in oxygen consumption.

Answer 37

increases oxygen consumption increased aerobic respiration more ATP is needed by msucles oxygen required to convert lactate into pyruvate

Question 38

Describe how a spirometer trace can be used to calculate the respiratory minute ventilation

Answer 38

find ventilation rate tidal volume x ventilation rate

Question 39

Describe how a spirometer trace can be used to calculate the oxgen consumption

Answer 39

difference in volume between one peak and teh subsequent peak

Question 40

Describe how the sinoatrial node (SAN) is involved in bringing about a change in heart rate as the level of activity increases.

Answer 40

more depolarisation of SAN more impulses to the SAN more frequent waves of depolarisation from the SAN to the atria more frequent contraction of atria

Question 41

why does blood lactate concentration remain constant

Answer 41

sufficient oxygen supply for aerobic respiration heart/breathing rate increases lactate is broken down by liver

Question 42

Explain why some ATP is broken down during glycolysis.

Answer 42

hydrolysis of ATP phosphorylates glucose it supplies energy to break down glucose to produce TP

Question 43

Explain the role of these carrier molecules in the electron transport chain.

Answer 43

recieve hydrogen from reduced NAD/FAD break hydrogen into protons and electrons electrons transferred by a series of redox reactions energy released is used to pump protons into intermembranal space

Question 44

Liver cells can absorb lactate from the blood. Deduce what happens to the lactate in these cells

Answer 44

lactate is converted to pyruvate pyruvate is converted to glucose glucose is used in respiration

Question 45

Explain the need for reduced NAD to be oxidised in a mitochondrion.

Answer 45

to regenerate NAD hydrogen can be delivered to ETC for ATP synthesis

Question 46

Devise a procedure using a respirometer to collect the data required to calculate the metabolic rate of a squirrel.

Answer 46

soda lime to remove CO2 measure volume of air entering and leaving chamber decrease in volume of air represents oxygen taken up by squirrel in respiration control temperature. measure mass of squirrel divide volume of oxygen used in a unit of time by body mass of squirrel

Question 47

Explain one way in which cartilage at the ends of bones in knee joint reduces wear and tear

Answer 47

Compressible to absorb shocks Smooth to reduce friction