Topic 7 - Exercise Flashcards
Too little exercise problems
Increased risk of obesity Coronary heart disease, build-up of cholesterol in arteries/blood vessels, CVD, atheroma Diabetes High blood pressure/stokes Osteoporosis
A structure with cells containing many nuclei?
Muscle
Too much exercise problems
Wear and tear on joints
Suppression of immune system/susceptibility to respiratory tract infections. Upper respiratory tract infections, reduced number of white blood cells.
Homeostatic control mechanism that restores pH to original level.
Negative feedback.
Sprinters: fast twitch muscle fibres are less red
Less myoglobin present
Less blood/ fewer red blood cells/less haemoglobin
As fewer capillaries present
Respiration is mainly anaerobic
How pH of blood increases to original after race
Low pH is due to acid (lactic acid and dissolved CO2) in the blood
Lactate (lactic acid) is taken to the liver
Oxygen debt/EPOC is used to convert lactate (lactic acid) to pyruvate (pyruvic acid) with the production of reduced reduced NAD (NADH2).
Lactate/ pyruvate is converted to glucose/glycogen
Chemoreceptors detect change in pH Increased nerve impulses from medulla Increased breathing rate Increased heart rate Dissolved CO2 from blood diffuses into alveoli
Blood vessels in skin with muscle: action to increase heat loss during exercise
Arterioles
Muscles contracting to restrict diameter in shunts (vasoconstriction)
Muscles relaxing to increase diameter in/dilate arterioles (vasodilation)
To redirect blood away from deeper arterioles into surface arterioles
To increase blood flow into capillaries towards surface, so more heat lost through radiation
Less fatigue with epicatechin
Increase inner: outer SA of mitochondria memebrne
Fatigue may be due to less ATP
Inner memebrane is the site of electron trnasport chain and oxidative phorpykation
More inner membrane, greater inner surface area, then more electron transport chain and more aerobic respiration
More ATP made - its synthesis involving chemiosmosis, H^+ down electrochemical gradient through ATP synthase
So delays onset of fatigue
(by 34 seconds in group A, thouse fed epicatechin)
Mice group A were given water containing epicatechiun at 1mg per Kg of their body mass rather than per mouse
Mice of different mass
Concentration is a controlled variable
Increases validity of investigation or conlusions
May be harmful in high doses
Effect of epicathechin on mitochondria
Increases the ratio of inner by 0.3/17.6%
Inner membrane is larger: IM/om
How SAN is involved in controlling heart rate
SAN is myogenic
Electrical activity from SAN causes atria to contract
actvity of SAN can be changed by nerve impulses e.g. controlled by the medulla
More impulses fom accelerator increases heart rate: more impulses from sympathetic nerve, noradrelaine, increase heart ratemore impulses from vagus nerve, more imulses from parasympathetic, acteylkcholine, decreases heart rate
*How her many cells have digested lactose
Lactase gene actiavted and transcribes
Synthesis of lactase
Hyroylsis of lactosre - glycosidic bonds broke, to produce glucose and galactose
*Using Hennrietta’s cells vs. using guinea pigs, mice
Better model than guinea pigs or mice
Snimal rights - fewer no ethical issues about animal welfare
Easy to culture
HeLa cells susepctible to the diease (being studied)
NAD/NAD+/NADox formed in ETC
Due to reduced NAD releasing electrons
Electrons go to carrier A/ ETC
H+ moved to inter-membranal space
ATP in ETC
Due to H+ passing through stakled partilce/ATPase/ATPsynthase
H+ passes down an electrochemical gradient
Suffiecient energy is released
To join ADP and Pi -oxidative phosprylation of ADP
This is by chemiosmosis
Respirometer with a screw clip, not a syringe
Screw clip open: coloured liquid does not move
Screw clip closed: coloured liquid moves towards the left, towards the organisms as they take oxygen in.
Potassium hydroxide is replaced with water ans screw clip is closed. Coloured liquid does not move. CO2 just replaces the oxygen taken in.
Name the proteins which make up the thick and thin filaments in muscle.
Actin - thin filament
Myosin - thick filament
Interaction between troponin and tropomysoin when a skeletal muscle fibre contracts
Ca++ bind to troponin
Troponin changes shape, moves
This displaces tropomyson away from myosin
Increased body temp. returned to normal.
Thermoreceptors in hypothalamus Detect the increase in core blood temp. Heat loss centre activated Autonomic , sympathetic,nervous system Impulses down motor neurones To effectors Head loss by vasodilation of blood vessel, sweat released, heat loss from blood through radiation
Shivering helps return and increase heat to normal
Shivering is muscle contraction
Which uses respiration/ATP - oxidative phosphorylation, ATP being converted to ADP and Pi
Which release heat to warm body
*Introducing gene into rat cells
Gene identified
Gene cut from DNA using a restriction enzyme
Gene in vector - retrovirus, virus, liposome, plasmid, bacteria
Mechanism for getting gene/vector into host cells of naked mole rats - micro injection, microprocessors, electro portion, gene gun, inhaler
Glycolysis to phosphorylation glucose
Changes Molecule R to molecule S
Phosphorylated glucose to 2 x phosphorylated 3 carbon compound
R - ATP adenosine triphosphate
S- ADP + Pi adenosine diphosphate , inorganic phosphate
Krebs cycle Aceytl CoA \+ 4 C compound To form 6 Carbon compound and 2H 1 x x 5 C compound 6H 1X X Back to 4 C compound
X = CO2
C has been removed from C6 or C5
Krebs cycle without acetyl CoA? Aceytl CoA \+ 4 C compound To form 6 Carbon compound and 2H 1 x x 5 C compound 6H 1X X Back to 4 C compound
KREBs cycle would stop 4 Carbon compound would accumulate 6 Carbon compound would not be synthesised 5 Carbon compound would also run short CO2 would reduce in quantity
Too efficient metabolism
Less food is required to deliver energy require,met
So more likely to have extra food not respites/surplus energy
Which could be stored in the body as fat
A larger VO’2 means more oxygen can enter mitochondrial and therefore more energy can be released from fuel
ADP and Pi Pyruvate Fatty acids NAD Acetyl CoA Water
Glycogen structure
Many alpha glucose monomers joined by 1-4 glycosidic bonds. Side branches present (1-6) glycosidic bonds
Increase in slow twitch fibres, increase in muscle efficiency
Slow twitch muscles carry out aerobic respiration/ full oxidation
Which produces more ATP than anaerobic
Energy not locked up in lactate
It takes longer for lactate levels to build up
Lower testosterone allows racing harder
More gonodotropins Use of excess fatty acids Respire to release fatty acids Increased fat metabolism Reduced requirement to replenish glycogen stores.
Ca2+ channel leak
Leads to muscle fatigue
Ca2+ leaks out of cell
Change in Ca2+ binding to troponin
Causes tropomyosin displacement
Change in myosin binding to actin
Loss of Ca2+ from cell, therefore force exerted by muscle is lower than expected
More Ca2+ in cytoplasm, results in less ATP so less muscle contraction
Transcription nucleic acids
DNA
mRNA
Translation nucleic acid
mRNA
tRNA
rRNA
DNA profiling
Obtain sample of cells
Extract DNA from cells
Increase amount of DNA: amplify using PCR
Use electrophoresis
Use a DNA gene probe
With a base sequence complementary to that on the variant
Match with known variant profile
Colder Water better for divers
A higher metabolic rate means more chemical reactions
More energy released/ATP used
Which released heat
Keeps divers warmer/ warm for longer/ able to swim without a wetsuit
Greenhouse gas
Examples and sources
CO2 - due to deforestation, land clearing, burning fossil fuels
Methane. from rice fields
Anaerobic bacteria action
Ruminant fermentation
Percentage increase
%before-%after / %before x100
A spirometer
Females and males
Calibration for volume, for time
Calculate tidal volume from trace: measure the height of one peak dm3
One peak = one breath
Breathing rate is the number of peaks per minute
Standardised group of males and females, same age, non smokers
Traces are taken at rest
Replicates are carried out
Calculate the mean from trace: add together the values for tidal volume and divide by total number of recordings
Peak expiratory flower over 35 to 85
Weakening of muscles
Loss of lung elasticity
Describe how a sprinter is able to release sufficient energy for the 100m sprint without having enough oxygen available for her muscles.
Energy is obtained from ATP ATP already in muscle cells in an ATP store ATP from glycolysis/substrate level phosphorylation. Glycolysis produces ATP rapidly Some aerobic respiration due to some oxygen present Glycolysis occurs in cytoplasm Need to recycle NAD+ Pyruvate is converted to lactate Anaerobic respiration Lactate tolerance Fast twitch muscle fibres Creative phosphate.
Lactate (lactate acid) build-up may prevent further increase in speed.
Lactate build up causes drop in pH / more acidic/increase in H+
This affects enzyme activity shape
This slows down glycolysis/ATP production/ anaerobic respiration.
Muscle contractions being affected
Fate of lactate after sprint
Lactate in blood Transported into broken down in liver Lactate is converted to Pyruvate This involves oxidation, reduced NAD production Pyruvate is then oxidised Kerbs cycle occurs This required extra oxygen: there is an oxygen debt Carbon dioxide and water are produced
Give reason why data reliable
Sample size large enough
Accurate measurements have been taken
Standard deviations are small
Men mean speed faster
Mean are faster than women
Due to differences in body structure : leg Ken have more muscle, longer legs, more fast twitch fibres
Physiological differences: testosterone
Mean speeds for the marathon are less than the 100m sprint for both men and women
Marathon distance is greater More aerobic respiration needed To reduce lactate production Anaerobic respiration is not efficient enough Oxygen debt Cannot be sustained over this distance Marathon runners use slow twitch fibres
Rate of resp apparatus
KOH solution absorbs carbon dioxide
Suggest a reason for absorbing Carbon dioxide in this apparatus
Reduces volume/ pressure of gas
Allows measurement oxygen used due to movement of liquid
Why is there a syringe in respiration apparatus
Returning coloured liquid back to zero
For calibration
To allow repetition
Describe how this apparatus could be used to measure the mean rate of respiration of woodlice
Constant temperature is used
A water bath is used
Over a fixed period of time, the measurement of volume /distance of coloured liquid is recorded
Rate can be calculated : divide the distance travelled by the fixed time, mm min-1
Replicates are obtained
A control is carried out e,g. With no woodlice
Animal welfare is important
Mass of woodlice should be recorded and kept constant where possible.
Muscles are attached to bones by
Tendons
In a joint, bones are joined to each other by
Ligaments
Muscles that work in pairs across a joint are known as
Antagonists
In key-hole surgery, the crucial ligaments are related using tissue from
Tendons
Fast twitch muscle fibres have
Few capillaries
High myoglobin content
Low glycogen content
Many mitochondria
Few capillaries - less aerobic respiration, requires less O2
Slow twitch fibres
Fatigue quickly
Have no myoglobin
Have low glycogen content
Have few mitochondria
Have low glycogen content
Fast twitch (short term)
Fatigue quickly Myoglobin glycogen present - doesn't have a glucose supply from blood. Few capillaries Few mito.
Slow twitch (long term)
Fatigue slowly Myoglobin Low glycogen content Glucose store, brought in by many capillaries Many capillaries Many mitochondria
Decision to ride the bicycle
Brain region
Cerebrum
Initiating an increase in sweating during the ride
Hypothalamus
Transmission of an impulse
Depolarisation - voltage-gated K+ channel closed
Voltage-gated Na+ channel open
Repolarisation
Voltage-gated K+ open, Na+ channel closed
Where neurotransmitters bind and initiate depolarisation in a myelinated motor neurone
Dendrites of the cell body of motor neurone
Sensory neurone v motor
Sensory Dendron myelinated, longer Axon shorter Cell body (centron, nucleus) not at the end, towards the middle No motor end plate
SAN ensures that oxygenated blood enters the aorta
Initiates electrical activity over atria
Causes atria to contract
Forcing the oxygenated blood into the left ventricle
Electrical activity from SAN received by AVN, travels through bundle His/ Purkyne fibres
Causing left ventricle to contract, forcing blood into aorta.
HR control during exercise
Treadmill test
Increase in respiration in muscle cells
More CO2/ carbonic acid in blood
More lactate, lactic acid in blood
Chemoreceptors in medulla stimulated
Cardiovascular control centre in medulla
Autonomic nervous system/sympathetic nerve
More impulses from medulla, CV control centre to SAN
More noradrenaline, norepinephrine released onto SAN.
SAN excitation rate increased
Causing an increased heart rate
74 beat per minute
Time taken for this ECG with 10 beats
1 beat = 0.81
60/74
10 beats = 8.1 seconds
ECG
x and y axis
x axis is time
y axis is milivolts
Two groups : hot the warm, warm then hot
No bias
Contributed to validity
Hot object desensitises
Therm preceptors not harmed, overstimulated, habituated due to high temp
Physical and emotional experience: same area?
Suitable scanning technique?
fMRI operates in real time
As experience will be short lived
Active areas will light up, be coloured, on the image
High resolution as areas involved may be small
Safer
Area just above hypothalamus
In middle of brain
Valid conclusion?
Conclusion is valid
Because mean feeling scores similar for both
Difference between postive and negative scores are similar
SD as a measure of variation from the mean
Sad similar physical and emotional when experience is positive
Overlap for positive and negative
Effect of light in retina
Retina in dark for two hours
Recovery by rod cell pigment from bleaching
Rod cells during two hours of darkness
Opsin uncouples from the rod cell surface membrane
Trans retinal converts to cis retinal
Rhodopsin is reformed from posing and retinal
This results in dark adaptation
Permeability of the cell surface membrane to Na+ increases - Na+ channels open
Hyperpolarisation of cell decreases
More neurotransmitter is released
Light intensity on mean peak voltage of depolarisation (mV)
up to 9AU
The greater the light intensity, the less neurotransmitter there is binding to the neurone present.
Inhibition is removed: more Na+ channels open more Na+ diffuses into neurone
So peak voltage of depolarisation becomes more positive
At high light intensities from 9AU
No NT binding
Sufficient Na+ enters
So action potential achieved
Objections to use of rats
Rats have rights - lack of consent given
Rats made blind, harmed, causes pain, may require killing
15 samples may not be sufficient for a reliable investigation
Rat retina may not behave like human retina so investigation has no potential medical application. Tissue culture is available.
Respiration experiment
Anaerobic respiration
Absent KOH solution
What does the coloured liquid do?
Colour liquid does not move.
No O2 or CO2 production.
Aerobic respiration
KOH absent
What does liquid do?
Does not move
CO2 produced replaces O2
Aerobic resp
Present KOH
Coloured liquid moved to left, towards organism
Colour liquid does not move.
No O2 or CO2 production.
Explain investigation 1
Anaerobic
No KOH
As anaerobic no O2 absorbed
No CO2 produced
So no change in volume pressure so liquid does not move
Since for each 6C glucose respired, 2x3C lactate formed
Aerobic respiration 2 and 3 : reduced NAD formed (NADH2+/NADH + H+)
Its fate?
Reduced NAD from glycolysis enters mitochondria, moves through outer mitochondrial membrane
Moves to inner membrane of mitochondrion
Becomes oxidised/NAD/NAD+
As electrons transferred to electron transport transport chain
Fate of hydrogen ions: pumped into membrane space.
NAD returns to Krebs cycle/ matrix
Invest 3 aerobic clip closed
Used for rate resp experiment with two different tissues
Same mass of each tissue
Time being recorded for a set distance travelled by coloured liquid or distance coloured liquid travelled in a set time
EPO increases red blood cells
EPO less effect on sprinters: fast twitch fibres
RBC will carry and supply oxygen
Low number of mitochondria present in fast twitch
So additional oxygen may have limited additional effect
Poor blood supply/capillary network in fast twitch muscle so little additional oxygen, RBC, received
In fast twitch respiration is primarily anaerobic
Short time duration of race,distance travelled means minimal additional blood supplied to muscles in timeframe
Ethical reasons to ban performing enhancing drugs
Not being fair
Poor role model for youngsters
Health risk to athletes
Cost to NHS, medical services of health implications
Spirometer trace
Breathing rate and tidal value
Breath identified
Time for one or several peak
Method for tidal volume e.g height from peak to trough on trace
Calibration for volume
Ventilation rate
Breathing rate x tidal volume
Rate of blood passing factors other than heart rate
Stroke volume Strength of cardiac muscle contraction Blood viscosity Size of atria, ventricles,chambers Adrelanin
Describe increase in heart rate
In O2 uptake and ventilation rate
There is little difference in ventilation rate does not increases as much
Oxygen uptake increases
Increased heart rate leads to increased O2 uptake
There is more blood passing through lungs
Oxygen diffuses into blood
Diffusion gradient being maintained
Oxygen diffuses in faster
Conclusions
Increased hear rate from 50 to 109 increases oxygen uptake, increases ventilation rate less
Heart rate has a greater effect on oxygen uptake than in ventilation rate
Skin to Gill neurone pathway
Skin to Sensory neurone, relay neurone, to motor neurone to Gill.
Running and change in core temp.
Increases in first 30min
More muscle contraction, respiration
Heat energy released
More heat produced than lost
Constant core temp 60-100mins constant
Detection of temp change, temp receptors Hypothalamus More sweating Loss of heat due to evaporation of water Vasodilation of arterioles Loss of radiant heat Heat gained equal heat lost Negative feedback
More water lost
Core temp increase
Dehydration No longer sweating Cooling mechanisms failing Heat production greater than heat loss Increase of pace
Ligament function
Holds, attaches bones together
Still allows movement at the joint
Using tendon to repair torn ligament
Slow recovery
Physiotherapy
Time needed for repair
Ligament has more elastic fibres
Tendon is inelastic, less flexible
Need to gradually stretch repaired tissue
Keyhole surgery benefits
Less damage to tissue Short time for recovery Social benefit - more patients can be treated Cheaper than invasive surgery Less anaesthetic needed
Muscle fibres with few mitochondria
Fast twitch fibre, type II
Why does fast twitch fatigue quickly?
ATP supply is limited Anaerobic respiration Lots of lactate pH is lower Affects enzymes Prevents muscle contraction
Anaerobic respiration I’m fast twitch muscles
Energy from ATP despite few mito
ATP from phospryltaiom of ADP
Energy required
Glycolysis - glucose converted to Pyruvate
Pyruvate converted to lactate - reduced
Makes NAD available
Anaerobic respiration
In cell cytoplasm,
ATP from oxidative phosphorylation in mitochondria
Phosphocreatine is involved in production of ATP
Process pre- Krebs
Glycolysis
Krebs waste product
CO2
Reduced molecule In Krebs
NAD
Pyruvate Acid
Molecule B
Molecules C
Aerobic resp
Difference of O2 uptake for different respiratory substrates
Oxygen to oxidise hydrogen as hydrogen acceptor of electron transport chain
Reduced coenzyme /NAD/FAD
Reduced coenzyme from glycolysis /Krebs cycle
Depends on diffusion rate, molecular sze
Oxidation level of substrate e.g H:O ration in molecule
Relative quantity of reduced coenzyme produces
pH effect of Pyruvate more favourable for enzyme
More carbon atoms, faster O2 uptake
Lactate rapid O2 uptake
Lactate can be converted to Pyruvate
Increases oxygen requirement - oxygen debt
Most potential for oxidation - can make the most reduced coenzyme
*Myogenic
Stimulation generated from within muscle - no external stimulation
Brings about depolarisation
Muscular contraction in heart
Blood movement control
SAN - sinoatrial node Initiates depolarisation Passes through wall of atria Causes atrial systole AVN conducts vents led Purkyne fibres/ bundle of His Ventricular systole, follows from apex Atrioventricular values closed and prevent flow to atria. Semi-lunar valves opened by pressure Blood forced into arteries Changes pressure in diastole closes semilunar valves
Mean rate resp units
mm min-1
Seeds in the experiment with nitrogen gas continued to germinate
Place of movement of liquid
No oxygen a valuable, no oxygen uptake
Anaerobic respiration
Carbon dioxide produced is absorbed
No net change of volume, pressure of gas.
Rate of resp experiment
KOH
Absorbs CO2
Carbon dioxide produced in respiration
Affects volume and pressure of gas
Allows measurement of oxygen used
Valid comparison
Germinating seeds in air and insects
Mass of organism may differ
Use Sam mass , express results per unit mass
Temp changes
Control temp using a water bath
Pressure may affect volume of gas
Use control of mo organism at the same time
Role SAN in controlling heart beats
Initiates heart beat
Starts excitation, depolarisation
Determines heart rate
Muscle contraction for holding steady
Extensor and flexor
Muscle contraction when lifting upwards
Flexor
Attaching muscles to bones
Tendons
Why antagonistic pairs
muscles cannot extend themselves
Need opposing muscle to extend
Antagonistic muscle allows control of movement
Contracting handing pattern
All fibres same length as original
Z lines are closer
More overlap of actin and muses in
Role of Ca2+ and ATP contraction
Vesicles, sarcoplasmic reticulum, contain calcium ions
Binds to troponin
Tropomyosin moves exposing minding sites for myosin
*Needs ATP to remove calcium ions
ATP provides energy for changing shape of myosin
ATP is required to break cross bridge
ATP for synthesis of neurotransmitter
Name enzyme (X) involved in chemiosmosis
ATase/=ATPsynthase
H+ high conc maintained in the intermembrane space
H+ ions reduced from NAD H+ pumped into inter membrane space Energy needed for pump Movement of electrons along ETC ETC on inner membrane
H+ concentration gradient for making ATP
H+ ions follow diffusion gradient This causes an energy change Makes energy available ATP is formed This occurs on the stalked particles ATP is energy source for biological processes
Effect of ectopic beat in heat activity - an upside down peak
Changes in electrical activity, depolarisation of heart
Peak is reversed
Peak is earlier than expected
No change in pressure in pulmonary artery
Because little blood in ventricles
Missed normal wave, longer gap before next wave
Missed effective contraction after E
Early depolarisation leaves ventricle insensitive
Wave of depolarisation is prevented
Refractory period
Ban drug preface drugs reasons
Absolutists say drugs should not be used at any time
Should not allow athletes to be pressured into using drugs
Risk to health
Gain unfair advantage
Other harmful substances banned
Burden on care service
Relativist says that drugs could be used under some circumstances
They could be used for medication
Drugs in the body can be difficult to legislate for,
