TOPIC 3 ENERGY SYSTEMS - IB SEHS

3.1 Nutrition, 3.2 Carbs and Fat Metabolism, 3.3 Energy Systems

animal cells are

animal cells are

multicellular, eukaryotic and surrounded by plasma membrane

animal cells come in

various sizes and have irregular shapes

most animal cells range from

1 to 100 micrometers

how many approximate distinct cell types are in the adult human body

210

Ribosomes

site for protein synthesis and found in large number in all cells

Ribosomes are freely suspended

in the cytoplasm

ribosomes are attached to

the endoplasmic reticulum

the rough er

transport system of the cell

rough er

er bound to ribosomes

smooth er

er without ribosomes

lysosomes

digestive system of the cell

if lysosomes were not membrane bound

the cell could not use destructive enzymes

golgi apparatus

bodies that are the packaging centre of the cell, they are flattened stacks of membrane bound sacs

mitochondria

main energy source of the cell, they have their own hereditary material

nucleus

the house for most of the cells genetic material surrounded by a porous membrane

rna moves in and out of the

nucleus through its pores

proteins needed by the nucleus enter through the

nuclear pores

the nucleus controls the

activity of the cell

nucleolus

the dark spot in the nucleus, location for ribosome formation

ATP stands for

adenosine triphosphate

ATP

molecule in the cell that allows for quick and easy access to energy when needed by the cell’s organelles

atp is a type of chemical energy that

releases energy when the chemical bonds are broken

atp in action

a process in need of energy, atp comes and breaks phosphate groups giving one phosphate to the process, left with adp recharged through the mitochondria

atp in muscle contraction

atp provides the energy necessary for muscle contraction by enabling the myosin heads to detach from actin filaments and re-cock for another cycle of binding and pulling

the amount of stored atp in muscles is only enough to

last about two seconds when intense work is done

how atp is resynthesised depends on

duration and intensity

resynthesis of atp by the atp-cp

an anaerobic system used in explosive efforts to re-synthesize atp

cp

creatine phosphate

explosive efforts

short duration and high intensity

the atp-cp system is

fuelled by creatine phosphate

cp is stored in limited

quantities in muscles

following 10 seconds of maximal effort, the body can take about

3-5 minutes of passive recovery to fully restore the atp and cp levels to pre-exercise levels within the working muscles

ratio of work duration to recovery for the atp-cp system

1:20

atp-cp system is the main energy system for activities such as

shot put, high and long jump, golf swing and basketball rebounding

micronutrients

vitamins and minerals

type 1 vitamins

vitamin b and c, water soluble

different vitamin b’s

b1,b2,b3,b5,b6,b7,b9,b12

vitamin b function

helps body make energy from the food we eat and from red blood cells

vitamin b sources

meat, leafy greens, dairy, beans, lentils, whole or fortified grains

vitamin c function

growth and repair of body tissues helps the body make collagen

collagen

the protein necessary in creation of skin, tendons, ligaments and blood vessels

vitamin c sources

citrus fruits, green vegetables, berries, tomatoes, capsicum, guava and paw paw

type 2 vitamins

vitamin a, d, e and k, fat soluble

vitamin a function

helps in cellular differentiation, helps with vision, immune system functions, growth, bone formation, would healing and reproduction

vitamin a sources

yellow, orange and red fruits and vegetables, green vegetables

vitamin d function

absorb calcium, block release of parathyroid hormone, role in muscle function

sources of vitamin d

sunlight, fatty fish, fish oil, liver, beef and egg yolk

vitamin e funtion

antioxidant protecting vitamins a and c, red bloods cells and essential fatty acids from destruction

vitamin e function

whole grains, seeds, nuts, fatty meat, plant oils and leafy greens

vitamin k function

blood clotting, promoting bone health, helping to produce proteins for blood, bones and kidneys

vitamin k sources

leafy greens, milk, liver

anaerobic glycolysis system

predominant during high intensity, repeated efforts between about 10- 30 seconds in exercise

high intensity

85-95% of VO2 max

anaerobic glycolysis system is also known as

the lactic acid system

the respiratory and cardiovascular systems are still unable to meet the oxygen demand of the muscle necessitating

the contribution of atp by the slower but higher yield anaerobic glycolysis system

glycogen

storage for carbohydrate in the body

first steps in glucose are non-oxygen requiring and are know as

glycolysis

glycolysis splits the 6 carbon sugar glucose into

two molecules of the 3c compound pyruvate in the cytosol of the cell

two molecules of atp are produced

for every molecule of glucose

under anaerobic conditions, pyruvate is converted to

another 3C compound lactic acid

fast glycolysis

lactic acid breaks down spontaneously into lactate and hydrogen ions

lactate is exported

from the muscles to the liver by the bloodstream

in the presence of oxygen lactate can be

reconnected to pyruvate

anaerobic glycolysis is the main energy system for events such as

short swim distances, football midfielders and gymnasts during a floor routine

lactate and hydrogen ion accumulation results in

muscular fatigue

the ratio of work recovery duration for anaerobic glycolysis is

1:5

O2 deficit

quantity of O2 that would have been used if it were available

EPOC

excess post-exercise oxygen consumption

EPOC is

the quantity of O2 consumed post-exercise over and above resting levels

fast component of epoc

resaturation of myoglobin with O2

oxygen deficit

the difference between the oxygen required and oxygen uptake

oxygen deficit reflects the contribution by

the anaerobic energy systems

at completion of exercise atp

decreases dramatically and. amount of oxygen consumed remains above amount required at resting levels

volume of oxygen used during recovery from exercise in excess of resting oxygen consumption is

oxygen debt or EPOC

fast replenishment

restores the amount of atp and cp which in the muscles occurs within 2-3 minutes during passive recovery

fast replenishment facilitated by passive recovery as an activity that uses atp or cp will

slow down the rate at which it can be replenished

slow replenishment

results in the removal of lactic acid from the muscles

lactate threshold

the workload beyond which the rate of lactate removal falls below the rate of lactate production

lactate acid accumulation is correlated with

muscular fatigue

lactic acid formed by anaerobic glycolysis dissociates to form

H+ ions and lactate

lactate can be reconverted to pyruvate, glucose or glycogen by

the liver cells

other process requiring slow replenishment are tissue repair and replenishing metabolic fats hence

post exercise meal is recommended to aid recovery

Krebs Cycle

used to generate energy through oxidation of acetyl coA and used for synthesis of NADH and production of amino acids

results of krebs cycle

3x NADH, 1x FADH2, 1x GTD, 2x CO2

aerobic system

glycogen is broken down into a series of chemical reactions into pyruvic acid.

due to the presence of sufficient oxygen energy is released to

rebuild ATP

stage 1 of aerobic glycolysis

the breakdown of glycogen to pyruvic acid releases energy to resynthesis adp + pi to rebuild atp

stage 2 of aerobic glycolysis

krebs cycle

stage 3 of aerobic glycolysis

electron transport system

only system requiring presence of oxygen

aerobic energy system

aerobic energy system begins to contribute to the energy supply during exercise after

30 seconds

aerobic energy system is the greatest

energy yield

overall chemical reaction for aerobic cellular respiration

glucose and oxygen turn to carbon dioxide, water and atp

triglycerides can be broken down into

intermediate compounds of glycolysis, the link reaction or the krebs cyle

triglycerides are hydrolysed into

glycerol and 3 fatty acids

fatty acids broken in 2C by

beta-oxidation

each 2C enters krebs cycle as

acetyl coA

proteins are hydrolysed to

amino acids and they can be deaminated

remaining compounds after proteins are hydrolysed can be converted to

pyruvate, acetyl coA or intermediate compounds in the krebs cycle

energy continum

the relative contribution of all three energy systems to resynthesis of ATP.