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