This document discusses human anatomy and physiology notes related to energetics and the digestive system. It covers several topics including: 1) Adenosine triphosphate (ATP) which provides energy for cellular processes through its breakdown. ATP is produced through substrate level phosphorylation, oxidative phosphorylation, and photophosphorylation. 2) The roles and functions of ATP including in metabolism, synthesis, active transport, cellular structure and locomotion, cell signaling, and protein synthesis. 3) The creatine phosphate system which stores and transports phosphate to rapidly regenerate ATP during intense muscle contraction to provide energy over short periods.

1. HUMAN ANATOMY AND PHYSIOLOGY NOTES
RAMDAS BHAT
KARAVALI COLLEGE OF PHARMACY 1
ENERGETICS
(DIGESTIVE SYSTEM)

2. HUMAN ANATOMY AND PHYSIOLOGY NOTES
RAMDAS BHAT
KARAVALI COLLEGE OF PHARMACY 2
• What does it mean to have energy?
• Well, think about how you feel when you wake up in the morning. If you have lots of
energy, that probably means you feel awake, ready to go, and able to do what needs to be
done during the day. If you have no energy (maybe because you didn’t get your eight
hours of sleep), then you may not feel like getting out of bed, moving around, or doing
the things you need to do.
• While this definition of energy is an everyday one, not a scientific one, it actually has a
lot in common with the more formal definition of energy (and can give you a helpful way
to remember it).
• Specifically, energy is defined as the ability to do work – which, for biology purposes,
can be thought of as the ability to cause some kind of change.
• Energy can take many different forms: for instance, we’re all familiar with light, heat, and
electrical energy.
• Here, we’ll look at some types of energy that are particularly important in biological
systems, including kinetic energy (the energy of motion), potential energy (energy due to
position or structure), and chemical energy (the potential energy of chemical bonds).
• Energy is never lost, but it can be converted from one of these forms to another.
• Adenosine triphosphate (ATP) is a complex organic chemical that provides energy to
drive many processes in living cells, e.g. muscle contraction, nerve impulse propagation,
and chemical synthesis.
• It acts as a Coenzyme and help in the transportation of the metabolic energy
• When ATP is breakdown to form the ADP and the inorganic phosphate, the removal of
the covalent bond leads to the generation of energy.
• The structure of the ATP:
• ATP is one of the products of the aerobic respiration, phosphorylation, cellular metabolic
reaction, fermentation.
• It is used by the enzymes and other structural proteins and thus helpful in cellular motility
and also cell division and the biosynthetic reaction.
ENERGETICS

3. HUMAN ANATOMY AND PHYSIOLOGY NOTES
RAMDAS BHAT
KARAVALI COLLEGE OF PHARMACY 3
• One molecule of ATP contains Adenine, ribose and also the 3 phosphate groups
• ATP is produced when ADP reacts with the Phosphate in the presence of ATP synthase
releasing ATP and water.
• The ATP production happens in various phases
1. SUBSTRATE LEVEL PHOSPHORYLATION
2. OXYDATIVE PHOSPHORYLATION
3. PHOTOPHOSPHORYLATION
Substrate Level Phosphorylation:
• It involves conversion of ADP in the presence of high energy phosphate to form ATP
• It involves the Glycolysis where glucose is converted into Pyruvate releasing 2ATP and
2NADH2(that can give 6 ATP molecule later)
• Krebs cycle involves conversion of Pyruvate-----→ ACETYL COA into Oxaloacetic acid
yielding 3NADH2(3x3 ATP), 1FADH2(2ATP) and 1ATP and we get 12ATPs molecules
but for 2 KREBS CYCLE we get 24ATPs.
• Electron transport Chain that happens in the inner membrane of the mitochondria causes
pumping of the H+(in pairs) due to the dissociation of NADH2 and FADH2 into the
space between the inner and outer membrane of mitochondria ie intermembrane space.
Oxidative Phosphorylation:
• In oxidative phosphorylation the pair of H+ that was previously released into the
intermembrane space now passes into F0-F1 particle that yields the ATP synthase that
converts the ADP into ATP in the Matrix.
Photophosphorylation:
• Photophosphorylation refers to the use of light energy from photosynthesis to ultimately
provide the energy to convert ADP to ATP, thus replenishing the universal energy
currency in living things.
Functions of ATP:
• Metabolism, synthesis and Active transport
• Helps in the structure and locomotion
• Cell signalling
• Amino acid activation in protein synthesis
CREATINE PHOSPHATE:
• ATP-PHOSPHOCREATINE system is a that produces energy for the muscle contraction.
• ATP is converted to ADP by breaking of the phosphate bond releasing the phosphate that
is a energy.
• The process is Continous such that energy released or a phosphate is utilised by another
ADP molecule to form ATP.

4. HUMAN ANATOMY AND PHYSIOLOGY NOTES
RAMDAS BHAT
KARAVALI COLLEGE OF PHARMACY 4
• Creatine phosphate is stored in the muscle.
• Creatine phosphate contains the phosphate that gets break under the action of Creatine
kinase releasing Phosphate that can be utilised by ADP to produce ATP the process
happens during anaerobically.
• The system ATP-CREATINE PHOSPHATE SYSTEM provides energy for about
10seconds of intense workout.
• The system then recovers after 2mins of rest.
• The creatine left over after the release of Phosphate now moves to kidney where they are
excreted.
• The amount of creatine in the urea determines the health of kidney.
BASAL METABOLIC RATE:
Energy metabolism needed to
maintain body temperature and
body functions (regeneration of
cells, respiration, circulation etc)
at rest.
• 1.28 W/kg for males,
• 1.16 W/kg for females (higher
percent of fat do not need
metabolism).
• Children have higher surface to volume ratio more heat loss, also higher growth rate so
they have higher basal metabolic rate.