This document discusses solar energy and human nutrition. It provides an overview of the four spheres that make up the Earth's ecosystem (atmosphere, biosphere, lithosphere, hydrosphere). It then describes various biogeochemical cycles (carbon, oxygen, nitrogen, phosphorus, sulfur) and how solar energy and these cycles sustain life. Photosynthesis is identified as the key process by which plants convert solar energy into chemical energy in carbohydrates. Cellular respiration and the formation of ATP are explained as how organisms extract and use this stored chemical energy. Nutrients like carbohydrates, proteins and lipids that provide energy are also summarized.

1. Solar energy and human nutrition
Prepared by; Dr. Siham Gritly
University of Bahri
1Dr Siham M.O. Gritly
The aim of studying environment is to sustain life and our
surroundings to better life quality for people and other species

2. • Introduction
• OUR planet
Dr Siham M.O. Gritly 2

3. The Solar System consists of the
Sun and its planets and their moons
Earth is the third planet in Solar System
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4. Earth and its moon (satellite)
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5. Our earth
The planet earth is the larger ecosystem; it
composed of 4 sphere;
5Dr Siham M.O. Gritly
1-atmosphere include all gases
2-biosphere; include all live found
in our earth. integrating all living
beings and their relationships,
including their interaction with the
elements of the lithosphere,
hydrosphere and atmosphere.
3-lithosphere or geosphere include
soils, rocks, and fossil fuels.
4-hydrosphere; liquid water found
in our planet, (under, and over the
surface of the earth).

6. 4 spheres of the earth planet
Dr Siham M.O. Gritly 6

7. The atmosphere;
is the mass of the planets' air. Atmosphere has an
innermost layer known as troposphere, the second layer
is stratosphere, the mesosphere, The thermosphere and
The exosphere
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8. The atmosphere layers
1) The troposphere is the first layer above the
surface and contains half of the Earth's
atmosphere. Weather occurs in this layer.
2) The stratosphere the second layer after The
troposphere Many jet aircrafts fly in because it
is very stable.
the ozone layer absorbs harmful rays from the Sun
found in this layer.
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9. • 3) the mesosphere is the layer directly above the
stratosphere and directly below the thermosphere.
4) The thermosphere The outermost shell of the
atmosphere, between the mesosphere and outer
space, where temperatures increase steadily with
altitude.
5) The exosphere atmosphere This is the upper
limit of our atmosphere(space)
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10. Gases of atmosphere
The thin layer of gases that envelops the Earth is held in place by
the planet's gravity
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11. Solar energy and human
nutrition
• increasing agriculture productions lead to
increase energy flow in an ecosystem by
using the high quality energy (sun),
• continuous flow of energy is provided for
living organism as heat energy
• Any Ecosystem depends on two natural
fundamental process; Solar energy and
cycling of matter
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12. The Sun is Most Common Source of Energy in Every Ecosystem
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The flow of energy in
an ecosystem is an
open system; the sun
constantly gives the
planet energy in the
form of light while it
is eventually used and
lost in the form of
heat throughout the
trophic levels of a
food web
(high quality energy),
which is the main source of
energy to maintain life

13. • All types of ecosystems depend mainly on
solar energy or sun
• The Sun is the main source of energy that
sustain life on our planet, supply energy light
that used by green plant in the process of
photosynthesis.
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14. Photosynthesis; is the a process of how plant obtain its
carbohydrates (stored chemical energy) by using carbon
dioxide (CO2), sun light and green pigments
(chlorophyll) for production of carbohydrate and
oxygen.
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15. energy flow in and between
ecosystems (solar energy)
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Energy flow is the amount of energy that moves through a food
chain

16. According to the energy flow within
ecosystems there are three types;
• 1-solar powered ecosystem
• This types of ecosystem mainly depend on the
sun energy such as ocean, sea, grass land, deep
lake ecosystems.
• They characterized by their low productivities
due to the low of energy flow
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17. • 2-subsidized solar powered ecosystem
• In this ecosystem additional to solar energy it
subsidized by other types of energy flow and
thus lead to high productivities (increasing
number of living organisms)
• naturally subsidized solar powered
ecosystem
• Tropical rain forest
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18. • 3-fuel powered ecosystem
• This types of ecosystems include biomass and
geothermal energy,
• This types of ecosystem include cities and industrial
places.
• It characterized by their;
• -very high energy flow due to high population and
other animals (over populated), such energy needed
for industrial and transportation purposes.
• -very high productivities
• -highly polluted ecosystem
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19. energy flow and cycling of matters
The interaction between matter and energy is the
main important phenomena in ecology
• An example of energy flow in an ecosystem
would begin with the autotrophs that take energy
from the sun.
• Herbivores then feed on the autotrophs and
change the energy from the plant into energy that
they can use.
• Carnivores subsequently feed on the herbivores
and, finally, other carnivores prey on the
carnivores.
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20. Organisms' Role in the Flow of Energy
• All ecosystems are made up of three types of
nutritional groups;
• -producers; green plant (phytoplankton)
• Plants are a common example of producers in all
populations. They are able to convert carbon
dioxide into oxygen and glucose, a common sugar
consumed by most organisms.
• -consumers; herbivores, carnivores and
omnivores
• -decomposers; bacteria and fungi
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21. Food chains and food webs are representations of the predator-
prey relationships between species within an ecosystem or
habitat. Every known food chain has a base made of autotrophs,
organisms able to manufacture their own food
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22. Food chains and Food web;
• The position that organism occupies on a food chain is
called its trophic level, this position depends on whether it is
a plant or animal
• -First trophic level (the producer, green plant).
• -second trophic level or primary consumer (herbivores which
eat plant)
• -third trophic level, secondary consumers or carnivores which
eat herbivores
• -fourth trophic level, tertiary consumers carnivores eat small
carnivores
• -decomposers such as bacteria and fungi
• A food web is a series of related food chains displaying the
movement of energy and matter through an ecosystem.
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23. A biogeochemical cycle
cycling of matter; it is naturally process
that recycle nutrients in different chemical
forms from a biotic environment to living
organisms and then back to non-living
environment
• 1-gaesous cycles; such as carbon, oxygen,
nitrogen, in such cycles nutrients circulate among
atmosphere, the hydrosphere and living
organisms
• 2-sedimentary cycles; nutrients circulate among
the earth crust, the hydrosphere and living
organisms
• 3-water cycle or hydrologic cycle; is the
continuous movement of water on, above, and
below the surface of the Earth.
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24. Nitrogen cycle
*Nitrogen is the most abundant gas found in atmosphere, it
constitute about 78%of the air.
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*All living organisms required
nitrogen in different forms to
built or synthesized protein,
nucleic acids (DNA, RNA) and
other nitrogenous containing
compounds.
*Plant and animals cannot make
use of nitrogen in the form of
gases. Plant can only take
nitrogen in the form of Nitrate
"NO3" which they absorb from
the soil. Animals can obtain
nitrogen by eating plants or
animals, which eat plants.

25. Carbon cycle
The producer (plant) absorbs CO2 from the atmosphere and
uses it for production of carbohydrates (process of
photosynthesis).
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Carbon is the basic building block of
carbohydrates, fats, proteins and nucleic
acids (DNA,RNA). The carbon cycle is the
biogeochemical cycle by which carbon
exchanged among the biosphere,
hydrosphere, and atmosphere of the Earth.
Carbon cycle mainly based on carbon
dioxide "CO2". It is estimated that carbon
dioxide makes up about 0.03% by volume
of the troposphere. It is also found in
dissolved in water.

26. Oxygen cycle
Oxygen cycle connected with the carbon cycle.
Dr Siham M.O. Gritly 26
consumer take oxygen and
release carbon dioxide. Producers
use carbon dioxide and release
oxygen during daytime
(photosynthesis). Oxygen also
found dissolved in water for
aquatic life.
Decay by the action of bacteria
and fungi release back all
elements from organic bodies
again to the atmosphere where it
recycles again and again

27. Phosphorous cycle
*Phosphorous is an essential nutrient for both plants and animals.
It enter in the formation of nucleic acids molecules (DNA, RNA)
that carry the genetic characteristics and information of living
cells
Dr Siham M.O. Gritly 27
*It is also part of the chemical
compounds (ATP, ADP) adenosine tri-
phosphate adenosine mono-phosphate.
These chemical compounds responsible
for energy storage or known as the
currency energy of the body. Chemical
energy is stored for use by organisms
during cellular respiration and to be use
later for other activities that required
energy. *phosphorous also important
elements for formation of bones and
teeth in animals with the presence of
calcium and vitamin D.*in the
sedimentary phosphorus cycle, various
forms of phosphorous are cycled
through water, earth crust and living
organisms. Found mainly in the forms
of phosphate ions PO4 and HPO3

28. Sulfur cycle
*sulfur is an important nutrient for living organisms. It
is part of formation of some amino acids. Amino acids
are building block for tissues.
Dr Siham M.O. Gritly 28
*during this sedimentary sulfur cycle, sulfur
transformed into different compounds and
circulates through hydrosphere, earth crust,
atmosphere and living organism.
*sulfur found in large amount in nature (in
oceans, sedimentary rocks and as ions in soil
and water).
*most sulfur compounds present in the
atmosphere in the form of sulfur dioxide (SO2)
*sulfur found in living tissues.
*it enter atmosphere from natural sources as
gases;
-sulfur dioxide (SO2) and hydrogen sulfide (H2S
from active volcanoes
-hydrogen sulfide (H2S) that form by the decay
of organic matter (oxidation of organic matter)
by the action of anaerobic decomposers

29. • Basic building block for all matter are
• hydrogen,
• oxygen,
• carbon,
• phosphorus,
• sulfur,
• chlorine,
• fluorine,
• sodium,
• calcium etc. found in nature as molecules
Dr Siham M.O. Gritly 29

30. six major elements that occur in similar
proportions in all life-forms
• The cells of all organisms are made up primarily of six
major elements
• These elements; carbon, oxygen, nitrogen, hydrogen,
phosphorous and sulfur
• Nutrients are elements found in food
• Three types of nutrients that provide energy
• Carbohydrates, proteins and lipids
• energy: the capacity to do work. The energy in food
is chemical energy. The body can convert this chemical
energy to mechanical, electrical, or heat energy
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31. • Carbon is used to make carbohydrates, fats,
and proteins, the major sources of food energy.
• These compounds are oxidized to release
carbon dioxide, which can be captured by
plants to make organic compounds.
• The chemical reaction is powered by the light
energy of the sun
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32. Carbohydrates
the main source of energy (glucose)
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Carbohydrates are organic
compound consist of carbon,
hydrogen, and oxygen atoms.
ratio of hydrogen to oxygen is
2:1. Carbohydrates range from
simple monosaccharide (glucose,
fructose, galactose) to complex
polysaccharides (starch).

33. Proteins
are complex organic compound found in
animal and plant tissues.
Dr Siham M.O. Gritly 33
The protein molecules are nitrogen-
containing amino acids, in addition to
carbon, oxygen, and hydrogen.
Amino acids are the building block of
protein
Amino acids contain Carbon,
Hydrogen, Oxygen, Nitrogen, and
sometimes Sulfur
Amino acids have two function
groups (both of which are typically in
the ionized form)
1- NH2 Amino functional group
2-COOH Carboxyl functional group

34. Lipids
are long hydrocarbon molecules
storage of energy
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Lipids are chemical compound naturally occurring substance;
consist of carbon, hydrogen, and oxygen,
widely found in plant and animal kingdoms.
A molecule of dietary fat consists of several fatty acids (containing
long chains of carbon and hydrogen atoms), bonded to a glycerol.
They are typically found as triglycerides (three fatty acids
attached to one glycerol backbone).

35. ATP (adenosine triphophate)
ATP or adenosine tri-phosphate has the ability to enter
all cells. it is known as energy currency of the cells
• Main sources of energy is obtained from cellular
respiration (oxidation of carbohydrate, lipids &
proteins); Glucose the final end product of
nutrients metabolism is oxidized
• 1-glycolysis (aerobic – anaerobic)
• 2-Kerb’cycle (citric acid cycle)
• 3-Electron Transport Chain
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36. ATP is a source of high-energy phosphate
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ATP is present everywhere in the
cytoplasm and nucleoplasm of all
cells and essentially for all the
physiological mechanisms that
required energy.
*within the cells the nutrients
amino acids, fatty acids and
glucose react with oxygen
(oxidation) to form carbon dioxide,
water and energy.
Energy produced used to form
adenosine tri-phosphate

37. Glycolysis Phase one –energy requiring
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Glycolysis; splitting of
glucose molecule to
form 2 molecules of
pyruvic acid (pyruvate).
This process occurs by
10 steps of chemical
reactions, each reaction
is catalysed by one
specific protein enzyme
it has 2 phases

38. Glycolysis Phase two–energy yeilding
Dr Siham M.O. Gritly 38
Glucose--oxidation----
2lactic acid (the end
product of glycolysis
under anaerobic
condition) or pyruvate
(under aerobic
condition) + 2ATP
(net formation of
glucose oxidation).

39. kerb's cycle
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kerb's cycle is a series of
reactions in the
Mitochondria that bring
about the catabolism of
acetyl residues, liberating
hydrogen equivalent (2H)
which on oxidation lead to
the release of most of the
free energy of tissue fuels.
the acetyl residues are in the
form of acetyl Co-enzyme A
(active acetate).

40. Electron transport chain
The electron transport chain is third and
final common pathway in aerobic cellular
respiration to generate ATP.
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41. • During various steps in glycolysis and the citric
acid cycle, the oxidation of certain intermediate
precursor molecules causes the reduction of
NAD+ to NADH + H+ and FAD to FADH2.
• NADH and FADH2 then transfer protons and
electrons to the electron transport chain to
produce additional ATPs from oxidative
phosphorylation (is when phosphorylation is
coupled with biological oxidation)
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42. Other types of energy
Biomass is all biologically-produced matter based in
carbon, hydrogen and oxygen
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Wood is a typical source of
biomass
Biomass is a renewable energy source of biological
material derived from living, or recently living
organisms. In the context of biomass for energy this
is often used to mean plant based material, but
biomass can equally apply to both animal and
vegetable derived material
biomass is the only source of fuel for domestic use
in many developing countries.

43. Fossil fuels
Fossil fuels such as coal, oil and gas are also derived from
biological material, however material that absorbed CO2 from the
atmosphere many millions of years ago.
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Coal, oil and gas are
called "fossil fuels"
because they have been
formed from the
organic remains of
prehistoric plants and
animals
As fuels they offer high energy density
use of that energy involves burning the fuel, with the oxidation of the
carbon to carbon dioxide and the hydrogen to water (vapour).
these combustion products are usually released to the atmosphere,
returning carbon that trapped in it for millions of years back to
atmosphere and thus contributing to increased atmospheric
concentrations C2O

44. Geothermal energy;
heat contained in under ground rocks and fluids.
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Geothermal energy is the heat from the Earth. It's clean and
sustainable. Resources of geothermal energy range from the
shallow ground to hot water and hot rock found a few miles
beneath the Earth's surface, and down even deeper to the
extremely high temperatures of molten rock called magma

45. Ref.
• Johnson, D.L., S.H. Ambrose, T.J. Bassett, M.L. Bowen, D.E. Crummey, J.S. Isaacson, D.N. Johnson, P.
Lamb, M. Saul, and A.E. Winter-Nelson. 1997. Meanings of environmental terms. Journal of
Environmental Quality 26: 581-589.
• Skinner, B.J. & Porter, S.C.: Physical Geology, page 17, chapt. The Earth: Inside and Out, 1987, John
Wiley & Sons,
• Kennish, Michael J. (2001). Practical handbook of marine science. Marine science series (3rd ed.).
CRC Press. p. 35.
• Jules Pretty and Andy Ball Introduction to Environment and Society
• Barange M, Field JG, Harris RP, Eileen E, Hofmann EE, Perry RI and Werner F (2010) Marine
Ecosystems and Global Change Oxford University Press.
• Campbell, Neil A. (2009), Biology Concepts & Connections Sixth Edition page 2, 3 and G-9.
• Odum, EP (1971) Fundamentals of ecology, third edition, Saunders New York
• United Nations Environment Programme. Convention on Biological Diversity. June 1992. UNEP
Document no. Na.92-78
• Earth's Spheres. 1997-2000. Wheeling Jesuit University/NASA Classroom of the Future. Retrieved
November 11, 2007.
• Beckett B.S (1986), Biology, A modern introduction. Oxford university press
• The World's #1 Renewable Energy Network for News & Information 2013
• http://www.biomassenergycentre.org.uk/portal/page?_pageid=76,15049&_dad=portal
• http://www.darvill.clara.net/altenerg/fossil.htm
Dr Siham M.O. Gritly 45