Download Photosynthesis / Cellular Respiration

2.2.2 - Chemistry Recap – Everything you should remember from middle school
Name:
Background from yesterday:
The planet must contain essential complex chemicals if life is going to exist, or even appear. Life as we know it contains specific
combinations of the 6 elements required for all life: carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur (CHNOPS) that
are required for all life. They are used in different combinations to make proteins (used for structure, hormones, enzymes)
carbohydrates (served as fuel for energy), lipids (stored energy and to make cell membranes) and RNA/DNA (stores genetic
information used to make new cells). All the basic elements are formed in stars and distributed throughout space as a result of
giant explosions called supernovas. Since these essential chemicals are quite common in other places in the Universe we can
expect that the development of life somewhere else is also possible.
Building Block
(what is the
smallest piece
called?)
Carbohydrates
Proteins
Lipids
Nucleic Acids
(RNA / DNA)
Elements
that make
them up.
Draw the Building Block
What
exactly is
the drawing
to the left?
Main Purpose
(2-3)
Found in What
Foods
(3-4)
Basic Chemistry Review
1. What is an element?
2. What is the smallest recognizable form of an element? ______________
3. What are the 6 elements necessary for all life?
4. Why do those 6 elements atoms want to bond? (hint: think back to valence electrons)
5. How do we represent a bond within drawings?
6. What part of the atom is being affected / is in play when we are bonding two atoms? (nucleus, protons, neutrons, or
electrons?)
7. Two or more elements bonded together makes a _____________.
8. What is a mixture?
9. What is stored in bonds?
10. Why would a very complex sugar with lots of bonds contain more energy than a simple sugar with fewer bonds?
11. When breaking the bonds between these three foods to make the building blocks, what type of change is it?
12. 9th grade definition of a chemical changes:
13. 9th grade definition of a physical change:
14. Give 2 examples of chemical changes.
15. Give 2 examples of physical changes.
Chemical Models
Yellow: Hydrogen (H)
Red: Oxygen (O)
1. ____________________
2. ____________________
3. ____________________
4. Drawing w/ correct colors 
5. ____________________
6. Drawing w/ correct colors 
7. ____________________
8. Drawing w/ correct colors 
9. ____________________
10. Drawing w/ correct colors 
11. ____________________
12. Drawing w/ correct colors 
13. ____________________
Purple: Sodium (Na)
Green: Chlorine (Cl)
Photosynthesis / Cellular Respiration
1. What is an autotroph / producer?
2. What is a consumer / heterotroph?
3. What is a decomposer?
4. What organisms can actually do photosynthesis?
5. What is the formula for photosynthesis?
6. Explain photosynthesis in sentence form.
7. What is the main thing that organisms are making when they perform photosynthesis and what do they use it for?
8. How long ago did photosynthesis develop, and what was Earth’s atmosphere like before that point?
9. Why was the early atmosphere made up of those gasses?
10. Which organisms do cellular respiration?
11. What is the formula for cellular respiration?
12. Explain cellular respiration in sentence form.
13. What is the main thing that organisms are making when they perform cellular respiration and what do they use it for?
14. How are the equations for photosynthesis and cellular respiration related?
Basic Chemistry Review
An element is a substance made of entirely the same of atoms. Every
element has a specific number of protons found in the nucleus. This number
of protons is so important that it is called the atomic number and is used to
define the element. For instance, Carbon has 6 protons, Oxygen has 8
protons, and Uranium has 92 protons. The smallest unit of an element that is
still considered that element is called at atom. Atoms are made of protons (+)
and neutrons (0) that are found in the nucleus, and electrons (-) that are found
in the electron cloud around the nucleus. The electrons are arranged into
rings around the nucleus, as you can see within the image of oxygen to the
right. The only ring of electrons that matters when it comes to how atoms are going to interact with
other atoms is the outer ring. We call this outermost ring of electrons valence electrons. Basically,
every single atom wants to have 8 valence electrons, and if an atom doesn’t (like oxygen to the
right only has 6 valence electrons), it will bond with another atom (or more than 1 atom) to become
a compound.
The period table is beautifully organized in a
way so that every element in the same column
has the same number of valence electrons
(shown to the right), making it easy to figure
out which elements will interact with each
other. We call these interactions bonds and it
is these interactions that make life possible.
There are 6 elements that are essential for life
to form: C, H, N, O, P, S. For instance, the all important water molecule bonds together two
Hydrogen and one Oxygen to form H2O. When we draw this, we simply represent
a bond as a line between 2 atoms.
When two atoms are bonded together, we now have a compound (or a molecule). When these
bonds form, they are storing energy that will be released when the bonds are broken. The more
bonds that form (the bigger the molecule or compound), the more energy that is stored in that
molecule. If there are ever 2 elements, compounds, molecules, etc… that are together but are
NOT bonded, that is called a mixture.
When bonds are made (two atoms combining together) or bonds are broken (two atoms breaking
apart from each other) we have a chemical change occurring. Examples of chemical changes
would be photosynthesis, cellular respiration, your body breaking down food into smaller parts,
metal rusting, etc…
Physical changes occur when you don’t break bonds and don’t make bonds. The chemical
structure of whatever you are dealing with does not change. Examples of this would be a rock
breaking in half, water breaking down sand over time, a branch breaking off of a tree, or water
evaporating in the sun.
Chemical Models
The balls represent elements. The little sticks represent bonds between the elements. In
order for compounds to be formed, all of the holes in the ball should be filled with bonds.
Yellow: Hydrogen (H)
Red: Oxygen (O)
Purple: Sodium (Na)
Green: Chlorine (Cl)
1. Take a yellow ball. What substance is it?
2. Is it an element, compound, or mixture?
3. Take a yellow, red, purple, and green ball and hold it in your hand. Are you holding a
compound, mixture, or element?
4. Make water (H2O) molecule. Draw a picture of it.
5. Is water an element, compound, or mixture?
6. Make salt (NaCl). Draw a picture of it.
7. Is salt an element, compound, or mixture?
8. Make oxygen (O2). Draw a picture of it.
9. Is it an element, compound, or mixture?
10.
11.
Make a mixture of salt and water. Draw it.
Separate the mixture. Is this a chemical or physical change?
12.
13.
You can separate water with electricity. Draw what you would have left.
Was this a chemical change or a physical change?
Photosynthesis / Cellular Respiration
Quick background sidenote:
Autotrophs are organisms that can produce their own food from inorganic substances. It will then use that
energy to grown and reproduce. These organisms are also called producers. Generally these are algae, lichen,
some bacteria, and plants. But not all organisms can make their own food. Consumers, also known as
heterotrophs, need to obtain nutrients from other organisms. Decomposers are specific types of consumers that
break down the remains of dead plants or animals.
Photosynthesis
Only autotrophs (and not all of them, there are rare ones that use only chemicals) can perform photosynthesis.
They use energy from sunlight to combine carbon dioxide (CO2) from the atmosphere with water (H2O) to form
carbohydrates, specifically glucose. These glucose molecules store energy. Oxygen (O2) is a byproduct that is
released into the atmosphere.
carbon dioxide + water + sunlight  glucose + oxygen
CO2 + H2O + sunlight  C6H12O6 + O2
As we saw earlier, this process didn’t develop in bacteria
until half a billion years after life formed on Earth, however it
has still existed on Earth for 3.5 billion years. This release of
oxygen (O2) as a byproduct is the only reason that oxygen is
so prevelant within our atmosphere. Before photosynthesis
existed, the Earth’s atmosphere was mostly carbon dioxide,
methane, and sulfur, which were the gasses that were
spewed out during all of the early Earth volcanic activity.
Cellular Respiration
Producers then use some of the stored carbohydrates as an
energy source to carry out their life functions. Some of the
carbohydrates remain as biomass (the bulk of the plant, etc.).
Consumers such as animals, fungi, and bacteria get their
energy from this excess biomass either while living or dead
and decaying. In any case, all living things will do cellular
respiration, taking Oxygen (O2) from the atmosphere is
combined with glucose to release the energy stored in bonds.
Water (H2O) and carbon dioxide (CO2) are byproducts.
6 CO2
+
6 H2O
C6H12O6
+
6 O2
oxygen + glucose  energy + water + carbon dioxide
O2 + C6H12O6  energy(ATP) + H2O + CO2
Notice that photosynthesis and respiration are essentially the opposite of one another. Photosynthesis
removes CO2 from the atmosphere and replaces it with O2. Respiration takes O2 from the atmosphere and
replaces it with CO2. Photosynthesis ends with glucose, which we store energy with. Cellular respiration ends
in ATP, a molecule we use right now for energy. However, these processes are not in balance. Not all organic
matter is oxidized. Some is buried in sedimentary rocks when organisms die. The result is that over geologic
time, there has been more oxygen put into the atmosphere and carbon dioxide removed by photosynthesis
than the reverse.
Proteins
Protein is an important substance found in every cell in the
human body. In fact, except for water, protein is the most
abundant substance in your body. This protein is
manufactured by your body utilizing the dietary protein you
consume. It is used in many vital processes and thus needs to
be consistently replaced. You can accomplish this by regularly
consuming foods that contain protein.
Amino Acid
(each of the 20 has a different R group)
Purpose
Proteins make up most everything in your body. They are
used for structure and to build cells. Hormones and enzymes
(chemical signals sent through your body) are both made of
proteins. Antibodies that help keep your body healthy are
made of proteins.
Found in What Foods
Foods with protein include many healthy choices:
 Meat, fish, cheese, eggs
 Beans, lentils
 Nuts (almonds, pistachios, peanuts), seeds
Building Blocks and the Elements
Proteins are made up of basic repeating units called amino
acids. Each amino acid is made of Carbon, Hydrogen,
Oxygen, and Nitrogen, while some contain Sulfur. There are
20 different amino acids found in nature, your body makes 12
of them. These amino acids will connect together to form
longer chains called proteins. Each different protein has a
different purpose in your body based on the order of the
amino acids (like letters being rearranged to make different
words).
20 different amino acids
(Notice the top is the same for each)
Protein (made of 3 Amino Acids)
Carbohydrates
Carbohydrates are the sugars, starches and fibers found in fruits,
grains, vegetables and milk products. Though often maligned in
trendy diets, carbohydrates — one of the basic food groups —
are important to a healthy life. They are called carbohydrates
because, at the chemical level, they contain carbon, hydrogen
and oxygen.
Purpose
Carbohydrates are the body's main source of energy. There are
two major types of carbohydrates: simple and complex.
Simple carbohydrates are simple sugars (glucose and fructose
found in fruits, vegetables, honey, etc…) and are used for energy
in the next few hours. Complex carbohydrates (starches found in
rice, bread, pasta, etc…) are used for stored energy for the next
few days.
Found in What Foods
Foods with carbohydrates include many healthy choices:
 Whole grains and foods made from whole grains (like some
rice, potatoes, oats breads, cereals, crackers, and pasta)
 Fruits, vegetables, and their respective juices
 Sugar, syrup, honey, and agave
Building Blocks and the Elements
Carbohydrates are made up of basic repeating units called
monosaccharides. Each monosaccharide is made of Carbon,
Hydrogen, and Oxygen. Glucose (C6H12O6) is an example of a
monosaccharide. Monosaccharides are the simplest sugar of all.
These monosaccharides will connect together to form longer
chains, with the longer the chain, the more complex the sugar
and the more energy is stores to be used later.
Monosaccharide (glucose, fructose)
(Single Sugar)
Disaccharide (sucrose)
(Double Sugar)
Polysaccharide (starch, cellulose)
(Many Sugar)
Lipds
Lipids, also known as fats, play multiple roles in the body.
Fats are broken down in the digestive tract to form individual
fatty acids and cholesterol molecules. Fatty acids and
cholesterol are key components of the membranes that
surround all cells. Cholesterol can also be used to make
many other compounds in the body, such as steroid
hormones. Finally, fatty acids represent an important source
of energy, particularly for the purposes of long-term storage.
Cholesterol is a type of lipid, and within cholesterol there are
saturated fats and unsaturated fats. Saturated fats are
considered the “healthy fats” while unsaturated fats are
considered the “unhealthy fats.”
Purpose
Lipids have a variety of purposes in the body. They are used
as the key component of membranes that surround cells,
they are used for long term energy storage, they are used for
insulation (think blubber in animals), and they are used as the
basis for steroid hormones in vertebrates.
Found in What Foods
There are healthy and unhealthy lipids.
 Healthy lipids include avocados, almonds and most
nuts, fatty fish,
 Unhealthy lipids include butter, lard, fried foods, and
vegetable oil.
Building Blocks and the Elements
The building blocks of lipids are glycerol and 3 fatty acids
connected together. When you connect all 4 of those parts
together, we call it a triglyceride. This is the singular
biomolecule where the building blocks DO NOT repeat over
and over to make longer chains. Each lipid is made of
Carbon, Hydrogen, and Oxygen, with nearly all of that being
Carbon and Hydrogen.
Triclygeride.
(Glycerol = line on the left going
up/down)
(Fatty Acid = 3 horizontal lines of C + H)
Nucleic Acids
Nucleic acids allow organisms to transfer genetic
information from one generation to the next. There are
two types of nucleic acids: deoxyribonucleic acid, better
known as DNA and ribonucleic acid, better known
as RNA. When a cell divides, its DNA is copied and
passed from one cell generation to the next generation.
DNA is organized into chromosomes and found within
the nucleus of our cells.
Nucleotide
Purpose
Nucleotides hold the genetic information to make every
protein in your body. DNA for instance, is analogous to
a cook-book. It is long and full of recipes, but you don’t
make everything in it at once. Just like a cook-book, you
only need find the instructions for the specific thing that
you are looking to make and follow those.
RNA is single stranded, while DNA is double stranded.
DNA is found the genetic basis for most every living
thing. RNA is used within copying DNA and making
proteins for the body.
Found in What Foods
Nucleic acids are found in all living things, but all living
things reproduce nucleic acids on their own. Organisms
do not need to eat anything specific to acquire them.
Deoxyribonucleic Acid (DNA)
Building Blocks and the Elements
Nucleic acids are made up of building blocks called
nucleotides (which are made of 3 parts). These
nucleotides string together to form long strands of DNA.
Each nucleotide is made of Carbon, Hydrogen, Oxygen,
Nitrogen, and Phosphorus. There are 4 different
versions of nucleotides (A, T, C, G) and the order of
those specific nucleotides makes up the instructions that
make you unique.
RNA (left) vs DNA (right)