Browsing Biochemistry
Name:
Period:
P1-3
Introduction to Molecules
12 points
P4-5
Metabolism
5 points
P6-7
Macromolecules
5 points
P8-9
Carbohydrates
10 points
P10-13
Proteins
5 points
P14-15
Lipids
5 points
P15-16
Nucleic Acids (DNA)
P17-18
Vitamins and Minerals
(used with diet analysis)
P19
Test review questions
8 points
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Name:
Date:
Period:
BROWSING BIOCHEMISTRY
Biochemistry is the chemistry of the living world. Plants, animals,
single-celled organisms... They all use the same basic chemical
compounds to live their lives. Biochemistry is not about the cells
or the organisms. It's about the smallest parts of those organisms,
the molecules. It's also about the cycles that happen to make
those compounds.
Those cycles that repeat over and over are the things that allow living creatures to survive on this
planet. It could be the constant process of photosynthesis in plants or the building of complex proteins
in the cells of your body. Every cycle has a place and they are just one building block to help organisms
live. In each of those cycles, molecules are needed and changed. It's one big network of activity where
each piece relies on all of the others.
Key Ideas
Define Biochemistry (include compounds):
__________________________________________________________________________
Why are cycles important in Biochemistry? Give examples of important cycles (think of your bottles!).
Combining Atoms – Understanding Symbols
Atoms are made up of a nucleus (center) with positive protons and neutral neutrons.
Surrounding the atom are negative electrons. Most atoms need to gain or lose atoms
to be electrically stable.
Sometimes one atom transfers electrons to another atom. The two atoms then stick
together like magnets. This is called an
ionic bond. Table salt is formed this way
when sodium and chlorine combine and the
chemical formula is NaCl.
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Other times atoms share electrons to become stable. This is called a covalent bond and it is much
stronger than an ionic bond. Most of the molecules of life (water, protiens, carbohydrates, fats) are
made of covalent bonds. Water consists of 2 Hydrogen atoms sharing electrons with one Oxygen atom.
The formula is H2O. You can also represent water in a ball and stick model:
Oxygen
hydrogen
Draw and label all of the parts of an atom below:
Compare ionic and covalent bonds (how are they different)
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METABOLISM
Metabolism is such a big word to explain a simple idea. We all need energy to survive. Plants, animals,
or bacteria. Energy doesn't just float around in a form we can use to
survive. We need to eat (mainly sugars) and digest food. That process
of chemical digestion and its related reactions is called metabolism.
Metabolism is the total of all of the chemical reactions an organism
needs to survive.
Sounds a lot like biology. Why is it called biochemistry? Two main
chemical processes make our world go round. There are two simple
chemical reactions. The first is called photosynthesis. That is the
reaction that builds sugars on planet Earth. The second process is cell
respiration. That's the breakdown of sugars to form ATP (an energy
molecule). You need to remember that the overall metabolism of an organism includes thousands of
chemical reactions. Cell respiration and photosynthesis are the cornerstones to life.
Key Ideas:
What is metabolism and what is the relationship between metabolism, digestion, and energy?
When you hear people say, “I have a fast metabolism.’ ‘ I have a slow metabolism.” What do you think
this means?
BUILDING UPPhotosynthesis
First, you need to build up the molecules that store energy. We'll start with
photosynthesis. It's no use explaining the breakdown of sugars without
telling you how they were made.
LIGHT (Energy) + CO2 + H2O→C6H12O6 + O2
This is the reaction that only plants can do (and some algae/bacteria). They
take sunlight and combine carbon dioxide (CO 2) and water (H2O). They
create Glucose (C6H12O6) and oxygen gas (O2). Remember, plants put the energy in glucose.
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BREAKING DOWNCell Respiration
It's metabolism and the process of cell respiration that
takes that energy out of the sugar related molecules.
C6H12O6 + O2→Usable Energy (ATP) + CO2 + H2O
Cells then use that extra energy to power the functions of
the cell. The energy isn't still floating around; it's stored in
an excitable compound called adenosine triphosphate
(ATP). ATP is the power molecule used in all organisms and
their cells to power the secondary reactions that keep us
alive (glycolysis is the first reaction).
Key Ideas:
Describe photosynthesis (Don’t forget its equation!)
Describe cell respiration (Don’t forget this equation either!)
What is ATP?
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Elements & Macromolecules in Organisms
Most common elements in living things are carbon, hydrogen, nitrogen, and oxygen. These
four elements constitute about 95% of your body weight. When atoms of elements combine they form
compounds (molecules) All compounds can be classified in two broad categories --- organic and
inorganic compounds.
Organic compounds are made primarily of carbon. Carbon has four outer electrons and can form four
bonds. Carbon can also bond to other carbon molecules forming double, triple, or quadruple bonds.
Organic compounds also contain hydrogen. Since hydrogen has only one electron, it can form only
single bonds.
Each small organic molecule can be a unit of a large organic molecule called a macromolecule.
There are four classes of macromolecules:
Carbohydrates (polysaccharides: Poly = Many, Saccharide-Sugar) – structure and energy storage
Lipids (fats or fatty acids) – membranes, energy storage, steroids
Proteins (also known as Polypeptides: Poly-many, Peptide – a type of bond) – enzymes, signal
molecules, structures, transport
nucleic acids (such as DNA & RNA). Information storage, energy transfer
Carbohydrates and lipids are made of only carbon, hydrogen, and oxygen (abbreviated C H O).
Proteins are made of carbon, hydrogen, oxygen, and nitrogen (abbreviated C H O N).
Nucleic acids such as DNA and RNA contain carbon, hydrogen, oxygen, nitrogen, and phosphorus
(abbreviated C H O N P).
The body also needs trace amounts of other elements such as calcium, potassium, and
sulfur for proper functioning of muscles, nerves, etc. Color each of the elements
according to the color listed next to the element's symbol. Color code the squirrel &
carrot on the next page with the correct proportion of each element's color.
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The four main classes of organic compounds (carbohydrates, lipids, proteins, and nucleic
acids) that are essential to the proper functioning of all living things are known as
polymers or macromolecules. All of these compounds are built primarily of carbon,
hydrogen, and oxygen but in different ratios. This gives each compound different
properties. Remember our models!
C = carbon: can form 4 covalent bonds
O = oxygen: can form 2 covalent bonds
or ionic bonds
H = Hydrogen: Can form 1 covalent bond
N = Nitrogen: Can form 3 covalent
bonds
P = Phosphorous: Can form 3 covalent bonds
K = Potassium: forms ionic bond
S = Sodium: forms ionic bond
Ca = Calcium: forms ionic bond
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Carbohydrates are used by the body for energy and structural support in cell walls of plants and
exoskeletons of insects and crustaceans. (Like Cellulose, which is in wood and the cell walls of
plants. You know that shirt you're wearing? If it is cotton, that's cellulose, too!) They are made of
smaller subunits called monosaccharides (mono=one, saccharide=sugar).
Monosaccharides have carbon, hydrogen, and oxygen in a 1:2:1 ratio.
Monosaccharides or simple sugars include glucose and fructose. Although
their chemical formulas are the same, they have different structural
formulas. These simple sugars combine to make disaccharides (double sugars
like sucrose which is table sugar) and polysaccharides (long chains like
cellulose, starch, and glycogen).
Read pages 158-159 in your textbook. Write definitions in your own words for:
Polymer
Starch
Glycogen
Cellulose
Key Ideas:
What are carbohydrates used for?
Describe monosaccharides (structure and ratio)
Describe disaccharides and polysaccharides.
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Glucose Molecule
H
O
H
C
H
O
C
H
H
H
C
O
C
O
H
H
O
H
H
C
C
O
H
H
Use the diagrams of glucose to tell how many carbons, hydrogens, and oxygens are in a single
molecule.
Carbon
Oxygen
Hydrogen
Look at figure 6.18 on page 159. In your own words explain how condensation reactions and their
opposite hydrolysis reactions. Give one example by drawing it below.
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Proteins are the working parts of living things, like gears and motors in machines. Proteins are made
of smaller parts called amino acids. They also act as enzymes helping to control chemical reactions in
organisms.
Color code the amino acid on this worksheet (carbon-black, hydrogen-yellow, nitrogen-blue, and
oxygen-red).
Basic Structure of Amino acid
H
H
N
H
C
O
C
H
R group
Use the drawing of the amino acid on this sheet to determine the number of bonds formed by:
______ Oxygen
_______Hydrogen
_______ Nitrogen
There are over 50 amino acids in nature, but only 20 are used to build proteins in living things.
They are all alike except for the atoms on their R group. This part makes them all different.
Condensation (or dehydration removal of a water molecule) links amino acids link together to form
chains called polypeptides. Polypeptide chains join to form proteins. The bonds holding amino acids
to each other are known as peptide bonds.
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One Hemoglobin protein
is made up of 146 amino
acids. Each red blood cell
in your body is covered
with thousands of these
to carry oxygen gas (O2)
and carbon dioxide gas
(CO2) around your blood.
Key Ideas:
What are proteins made out of?
What are two functions of proteins?
How are proteins formed (chemical process, bonds, etc.)?
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INTRODUCTION TO ENZYMES. . . THEY MAKE THE WORLD GO 'ROUND
We often talk about reactions and the molecules that change in those reactions. Those changes don't
happen on their own. If you leave a blob of protein in a Petri dish, will it just break down to the amino
acids? No. What will do it? Enzymes! Enzymes are the biological substance (proteins) that act as
catalysts. A Catalyst can trigger and speed up the COMPLEX
chemical reactions that occur everywhere in life.
LOCKS AND KEYS
When you go home at night and the door is locked, can it open
itself? Nope. You need a key that is just the right shape to fit in that
lock. Otherwise, you're stuck in the cold. Enzymes work in a similar
way (locks and keys). Enzymes complete very specific jobs and do
nothing else. They are very specific locks and the compounds they
work with are the special keys. In the same way there are door keys, car keys, and bike-lock keys,
there are enzymes for neural cells, intestinal cells, and your saliva.
Here's the deal: there are four steps in the process of an enzyme working.
1. An enzyme and a substrate are in the same area. The substrate is the
biological molecule that the enzyme will attack.
2. The enzyme grabs onto the substrate with a special area called the
active site. The active site is a specially shaped area of the enzyme that
fits around the substrate. The active site is the keyhole of the lock.
3. A process called catalysis happens. Catalysis is when the substrate is changed. It could be broken
down or combined with another molecule to make something new.
4. The enzyme lets go. Big idea. When the enzyme lets go, it returns to normal, ready to do another
reaction. The substrate is no longer the same. The substrate is now called the product.
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Lactase is an enzyme that allows people to break down the sugar in milk, which is called lactose. What
is biologically wrong with people who are lactose intolerant (can’t digest milk)?
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Lipids (Fats) are large, nonpolar (won't dissolve in water) molecules. Fats make up cell membranes
and organelle membranes. Lipids also serve as waxy coverings on plants, pigments (like chlorophyll
which makes plants green and is part of photosynthesis), and steroids. Lipids have more carbon and
hydrogen atoms than oxygen atoms.
The fat chain may be saturated (only single bonds between carbons) or unsaturated (contain at least
one double bond). Unsaturated fats are liquid at room temperature, come from plant sources (nuts,
olive oil), and are easy for the body to use (healthy).
Saturated fats come from animal sources (cheese, butter, meat) and is generally unhealthy.
Fats have a lot of energy stored
up in their molecular bonds.
That's why the human body
stores fat as an energy source.
When it needs extra fuel, your
body breaks down the fat and
uses the energy. Where one
molecule of sugar only gives a
small amount of energy, a fat
molecule gives off many times
more.
A special type of lipid called phospholipids help make up the cell
membrane. Two layers of these phospholipids make up the
membrane. Phospholipids have a "water-loving" hydrophilic head
and two "water-fearing" hydrophobic tails. On the cell membrane
on this sheet circle and label one phospholipid. Proteins are also
embedded in the cell membrane. Color the two proteins in the cell
membrane blue.
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Key Ideas
What are lipids (include chemical structure)?
What is the function of lipids?
Compare saturated and unsaturated fats (structure and examples of these)
Nucleic acids carry the genetic information
in a cell.
DNA or deoxyribose nucleic acid
contains all the instructions for making every
protein needed by a living thing. RNA copies
and transfers this genetic information so that
proteins can be made. The subunits that
make up nucleic acids are called
nucleotides. Color and label the parts of a
nucleotide (sugar-green, phosphate groupyellow, and nitrogen base-blue).
Nucleotide
P
N
S
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ATP used for cellular energy is a high energy nucleotide with three phosphate groups.
Color code the ATP (sugar-green, phosphate group-yellow, and nitrogen base-blue).
We will study DNA and ATP in greater detail later…
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Some of the other stuff…
Vitamins
Vitamins are smallish molecules that your body needs to keep itself running properly by building
enzymes which control the chemical reactions in your body. Vitamins are called coenzymes because
they work with the enzymes in our body. The human body needs 13 different vitamins:

Vitamin A (fat soluble, retinol) comes from beta-carotene in plants; when you eat betacarotene, an enzyme in the stomach turns it into Vitamin A.

Vitamin B (water soluble, several specific vitamins in the complex)

Vitamin B1: Thiamine

Vitamin B2: Riboflavin

Vitamin B3: Niacin

Vitamin B6: Pyridoxine

Vitamin B12: Cyanocobalamin

Folic Acid

Vitamin C (water soluble, ascorbic acid)

Vitamin D (fat soluble, calciferol)

Vitamin E (fat soluble, tocopherol)

Vitamin K (fat soluble, menaquinone)

Pantothenic acid (water soluble)

Biotin (water soluble)
In most cases, the lack of a vitamin causes severe problems. The following list shows diseases
associated with the lack of different vitamins:

Lack of Vitamin A: Night blindness, dry eyes

Lack of Vitamin B1: swelling of tissue, heart faliure

Lack of Vitamin B2: Problems with lips, tongue, skin,

Lack of Vitamin B3: diarrhea, dermatitis, dementia, and death.

Lack of Vitamin B12: Pernicious anemia (poor muscle formation)

Lack of Vitamin C: Scurvy: liver spots, bleeding from throat and nose

Lack of Vitamin D: Rickets: bone deformity

Lack of Vitamin E: Malabsorption of fats, anemia

Lack of Vitamin K: Poor blood clotting, internal bleeding
A diet of fresh, natural food usually provides all of the vitamins that you need. Processing tends to
destroy vitamins, so many processed foods are "fortified" with man-made vitamins.
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Minerals
Minerals are elements that our bodies must have in order to create specific molecules needed in the
body. Here are some of the more common minerals our bodies need:

Calcium - used by teeth, bones, nerves

Chlorine – digestive juices

Chromium

Copper

Fluorine - strengthens teeth

Iodine – Hormone formation

Iron - transports oxygen in red blood cells

Magnesium

Manganese

Molybdenum

Phosphorus – energy transfer in every cell

Potassium - important ion in nerve and muscle cells

Selenium

Sodium - important ion in nerve and muscle cells

Zinc
Food provides these minerals. If they are lacking in the diet, then various problems and diseases arise.
Water
As mentioned above, your body is about 60-70-percent water. We use water to break the bonds of
most polymers we use (hydrolysis) A person at rest loses about 40 ounces of water per day.
Water leaves your body in the urine, in your breath when you exhale, by evaporation through your skin,
etc. Obviously, if you are working and sweating hard then you can lose much more water.
Because we are losing water all the time, we must replace it. We need to take in at least 40 ounces a
day in the form of moist foods and liquids. In hot weather and when exercising, your body may need
twice that amount. Many foods contain a surprising amount of water, especially fruits. Pure water and
drinks provide the rest.
Fibers
Fiber is the broad name given to the things we eat that our bodies cannot digest. Fiber keeps
intestines healthy.
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Post Reading Questions:
1. Give the symbols for the elements that make up each of the following:
carbohydrates
lipids
DNA
proteins
2. Why do you think Carbon is the base for so many molecules? Think of our models! What could you
do with carbon?
3. Name the 4 types of macromolecules & give a function for each.
4. What process is used to link amino acids together, and small sugar units together?
5. What chemical reaction depends on water to break down large molecules?
6. Explain the difference between a disaccharide and a polysaccharide. Give an example of each.
7. Why are enzymes important to organisms?
8. What is the difference between a saturated and unsaturated fatty acid?
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