run for your life Flashcards
skeletal muscle
the type of muscle you use to move
tendons
attach muscle to bone
ligaments
attach bones together
antagonistic pairs
muscles that work together to move a bone. one relaxes as one contracts. they create opposite forces
flexor
muscle that bends a joint when it contracts
extensor
muscle that straightens a joint when it contracts
what happens when calcium ions bind to troponin
troponin changes shape
tropomysoin is moved by troponin
myosin binding sites on actin are exposed
(myosin head binds, forming actin-myosin cross bridge)
explain how myosin binding sites being exposed leads to muscle contraction
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)
describe interaction between troponin and tropomyosin that allow muscle contraction
troponin changes shape causing tropomyosin to move away from the myosin-binding sites
importance of primary sturtucre for functioning of ATPase (in muscle contraction)
primarys tructure determines interaction between R groups
primary sturcture determines tertiary sturcture
therefore affecting shape of active site
active site is complementary to ATP
describe how concentration of calcium ions around myofibrils is controlled
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
Explain how the extensor and flexor muscles bring about movement of the lower leg.
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
how do athletes with amputations are able to move their prosthetic limbs
during a race.
muslces are still attached to the lower leg and prosthetic limb is attached to lower leg
Describe two structural differences between fast twitch muscle fibres and slow twitch
muscle fibres.
fast twitch fibres have no mitochondria while slow twitch have many
fast twitch fibres have no capillaries while slow twitch have many
Explain how the structure of a muscle fibre is related to its specialised function.
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)
what is meant by no significant difference at 0.05 probability level
more than 5%/less than 95% likelihood
calculated value is less than critical value
Describe how the tertiary structure of myosin is related to its function.
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
why does force produced from mass increase then remain constant
increases because myosin binding sites are exposed
remains constant because all actin and myosin are interacting/all myosin binding sites are occupied
sarcolemma
cell membrane of muscle fibres
sarcoplasm
muscle cell’s cytoplasm
T tubules
folds
sarcoplasmic reticulum
network of internal membranes
how are myofirbils when resting
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
difference between slow and fast twitch
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
Importance of outer mitochondrial membrane being impermeable to hydrogen ions
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
how to determine safe dose of a drug
test drug on healthy individuals
test on group of individuals with condition
gradually increase dose
How does lactate fermentation work in animals
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
How is lactic acid broken down
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
Myogenic meaning
Can contract and relax without recovering signals from neurones
Heartbeat process
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
Explain how rate of breathing is controlled
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
How does excercise increase breathing rate
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
Cardiac output
Cardiac output = heart rate x stroke volume
Tidal volume
Volume of air in each breath
Ventilation rate
Ventilation rate = tidal volume x breathing rate
Explain why it is necessary for the cardiac output of marathon runners to increase during
a race.
increase supply of oxygenated blood
to allow aerobic respiration
to provide energy
Explain the effect of exercise on the changes in oxygen consumption.
increases oxygen consumption
increased aerobic respiration
more ATP is needed by msucles
oxygen required to convert lactate into pyruvate
Describe how a spirometer trace can be used to calculate the respiratory minute ventilation
find ventilation rate
tidal volume x ventilation rate
Describe how a spirometer trace can be used to calculate the oxgen consumption
difference in volume between one peak and teh subsequent peak
Describe how the sinoatrial node (SAN) is involved in bringing about a change in heart rate
as the level of activity increases.
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
why does blood lactate concentration remain constant
sufficient oxygen supply
for aerobic respiration
heart/breathing rate increases
lactate is broken down by liver
Explain why some ATP is broken down during glycolysis.
hydrolysis of ATP phosphorylates glucose
it supplies energy to break down glucose
to produce TP
Explain the role of these carrier molecules in the electron transport chain.
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
Liver cells can absorb lactate from the blood.
Deduce what happens to the lactate in these cells
lactate is converted to pyruvate
pyruvate is converted to glucose
glucose is used in respiration
Explain the need for reduced NAD to be oxidised in a mitochondrion.
to regenerate NAD
hydrogen can be delivered to ETC for ATP synthesis
Devise a procedure using a respirometer to collect the data required to
calculate the metabolic rate of a squirrel.
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
Explain one way in which cartilage at the ends of bones in knee joint reduces wear and tear
Compressible to absorb shocks
Smooth to reduce friction
