Download 1 - Intro to energy

What do athletes eat and
why?
Introduction to Energy
•Describe how the breakdown of ATP
occurs to provide energy
•State the main sources of energy for the
replenishment of ATP and describe how
they are used
WHAT DO ATHLETES EAT AND WHY?
•All chemical reactions in cells need a
molecule called ATP to provide them with
energy.
•ATP is the ‘energy currency’ of the cells.
•Energy is the capacity to do work
•Energy is measured in joules (J) or
kilojoules (kJ)
ATP = Adenosine Triphosphate
ATPase
ENERGY
ADP + Pi + ENERGY!
How does ATP provide energy?
 Each cell contains a ‘pool’ of ATP which is used to provide
energy – enough for 2-3 seconds of exercise
 The energy in ATP is chemical potential energy between
the phosphate bonds.
 ATP is hydrolysed (broken down using water) by the
enzyme ATPase to produce ADP + Pi (ADP = adenosine
diphosphate + phosphate group)
 In this reaction the bonds between the final phosphate
group is broken, releasing energy
 Enzymes can use this energy to drive chemical reactions.
 Once ATP has been broken down, it can be reformed
from ADP + P using energy from fuels such as glucose
ATP – ADP Cycle
Energy input
from fuels
e.g. glucose
ATP Synthesis
+
ADP + Pi
ATP
ATP Breakdown by ATPase
Energy released to
be used by cells
Resynthesising ATP
Energy
Source
Phosphocreatine
(PCr)
Glycogen
Triglycerides
Protein
Where is it
found in the
body?
How much
energy/ ATP
can it make?
How it is used to
synthesise ATP
Energy
Source
Where is it
found in the
body?
Phosphocreatine
(PCr)
Glycogen
How much
energy/ ATP can
it make?
How it is used to
synthesise ATP
Small
amounts
stored in the
muscle cells
1 ATP per PCr
molecule
PCr is broken down into P
and Cr, and this releases
enough energy to
synthesise ATP
Muscle
(350g) and
liver (100g)
2 ATP per glucose
in high intensity,
anaerobic
conditions,
38 ATP per
glucose in low
intensity, aerobic
conditions.
Yields 4kcal/gram
Glycogen is broken down
into glucose which is used
in anaerobic or aerobic
respiration.
Energy Source
Triglycerides
Protein
Where is
it found
in the
body?
Muscle
stores
and
stores in
adipose
tissue
around
the body.
How much
energy/ ATP can
it make?
How it is used to
synthesise ATP
Over twice as
much per gram as
compared to
glycogen – yields
9kcal/gram.
Triglycerides are broken
down into fatty acids and
glycerol, which go through
a process called beta
oxidation, and can then be
used as fuel for aerobic
respiration when plenty of
oxygen is available. Used in
conjunction with glycogen.
muscle
tissue
itself
Similar to
carbohydrate –
yields
4kcal/gram
Only used when glycogen
stores are running out,
amino acids are converted
into a molecule that is used
in aerobic respiration
Key Points
Write down the 3 key points of this
lesson!
Whiteboard or App
Exam Question
Gymnastic events can last up to 90 seconds. Explain how
the majority of energy is provided for these events.
(7 marks)
Mark scheme
7 marks for 7 of:
A. Anaerobic/without oxygen
B. (during first few seconds) stored ATP splits/breaks down
initially/ATP breaks down to ADP + P + energy
C. ATP-PC/system/phosphocreatine system/alactic system
D. PC = C + P(i) + energy/creatine + phosphate/PC broken down;
E. Energy used for ATP resynthesis/ADP + P + energy = ATP/ADP + PC
= ATP + C;
F. Lasts 5-10 seconds/limited supply
G. Lactic acid system/Lactate anaerobic system
H. Glycogen/glucose breakdown
I. Glycolysis
J. To pyruvate/pyruvic acid
K. Lactate/lactic acid formed