Download Review of Biochemistry Packet

Review of Biochemistry
Directions: Using the following word bank, fill in the blanks for questions 1-5.
Compound
Neutron
Covalent
Proton
Electron
Element
Ionic
1. Substances formed by the combination of two or more elements are known as
2. Simplest form of a substance that cannot be broken down is known as
3. A(n)
bond occurs when the electrons of 2 elements are shared.
4. A(n)
bond occurs when the electrons of 2 elements are transferred.
5. Label the following diagram of the atom.
6. Using the data table below, complete the diagram to the right. Be sure to indicate the number
of protons and neutrons in the nucleus and draw the
electrons in their appropriate electron shells.
NITROGEN
# of
# of
# of
Protons Neutrons Electrons
7
7
7
7. Carbon is considered the basis for life. Using your notes, explain what is important about
carbon’s electron arrangement.
8. Using your notes, explain why elements want to have 8 electrons in their outer shell.
9. Using your notes, identify where in a compound energy is stored.
Organic Vs. Inorganic Compounds
1. Which elements are present in ALL organic compounds?
1
2
hydrogen and oxygen
nitrogen and carbon
3
4
nitrogen and oxygen
hydrogen and carbon
2. The chart indicates the elements contained in four different molecules and the number of
atoms of each element in those molecules.
a. Which molecule can be classified as organic?
1.
A
2
B
3
C
4
D
b. What elements must be present for a molecule to be considered organic?
3. Which formula represents an organic compound?
1
Mg(OH)2
2
NaCl
3
C12H22O11
4
NH3
4. What substance could be represented by the letter X in
the diagram below?
1
2
3
4
carbohydrates
ozone
carbon dioxide
water
5. Determine if the following compounds are organic or inorganic.
a. H2O
b. HCl
c. C6H12O6
d. (CH3)2CO
e. Al(NO3)3
f. C3H5NO
g. B4C
Lipids
Lipids are large molecules containing the stored energy of numerous carbon-carbon and
carbon-hydrogen bonds. They are found in foods such as fats and oils. Lipids are synthesized
from fatty acids and glycerol. When stored in fat tissues in the body, they function as stored
energy. Lipids contain more energy than any other molecule due to their high number of
chemical bonds. Lipids together with proteins are needed to synthesize cell membranes.
Excessive consumption of fats is a common problem in the American
diet. However, it is important to consider not only the total amount
of fat consumed, but also the kinds of fats consumed. Fats may be
saturated or unsaturated.
A molecule of saturated fat contains all the hydrogen atoms it can
hold (Refer to Figure). The carbon-carbon backbone of its fatty acid
component contains only single bonds. Saturated fats are solid at
room temperature. They are found in meat and in milk products.
An unsaturated fat, however, contains double bonds in the fatty acid
portion of the molecule (Refer to Figure). Unsaturated fats are oils
that are found at room temperature. They appear considered
healthier than saturated fats.
1. List two examples of lipids.
2. What is one important function of lipids?
3. What are the building blocks of lipids?
4. Explain the difference between saturated and unsaturated fats.
5. In living organisms, lipids function mainly as
1.
2.
3.
4.
Sources of stored energy and transmitters of genetic material
Sources of stored energy and components of cellular membranes
Transmitters of genetic material and catalysts of chemical reactions
Catalysts of chemical reactions and components of cellular membranes
6. The diagram shows the building blocks of a lipid molecule.
a. Determine the name of each type of molecule.
i. Molecule A:
ii. Molecule B:
b. How many molecules of A normally combine with
one molecule of B to form a single fat molecule?
1. 5
2. 6
3. 3
4. 4
Carbohydrates
You may have heard of runners eating large quantities of spaghetti or other starchy foods the
day before a race. This practice is called carbohydrate loading. It works because the
carbohydrates’ main function is to be used by cells to store and release energy.
A carbohydrate is an organic compound composed the following elements:
carbon, hydrogen, and oxygen with a ratio of about two hydrogen molecules
to every one oxygen molecule (2 Hydrogen : 1 Oxygen).
The simplest type of carbohydrate is a simple sugar called a
monosaccharide. Common examples include glucose and fructose. (Note
the both end in -ose). Two monosaccharides form a disaccharide, a two-sugar
carbohydrate.
The largest carbohydrate molecules are known as polysaccharides,
polymers (large molecules) composed of many monosaccharide subunits.
Starch, glycogen, and cellulose are examples of polysaccharides. Starch is used as food storage
by plants. Mammals use glycogen as their storage carbohydrate. Cellulose is found in the cell
walls of plants and cannot be digested by humans.
1. List two examples of carbohydrates.
2. What is one important function of carbohydrates?
3. What elements are carbohydrates composed of?
4. Explain the difference between a polysaccharide and a monosaccharide.
5. Which chemical formula represents a carbohydrate?
1. CH4
2. NaCl
3. C12H22O11
4. CO2
3. ribose
4. starch
6. Which compound is a polysaccharide?
1. glucose
2. maltose
7. Two examples of carbohydrates are
1. fatty acids and glycerol
2. sugars and starches
3. fats and waxes
4. amino acids and alcohol
8. In humans, excess glucose is stored as a polysaccharide known as
1. glycogen
2. glycerol
3. maltose
4. cellulose
9. Two monosaccharides bond together to form a disaccharide. This process is known as
1. hydrolysis
2. dehydration synthesis
3. respiration
4. photosynthesis
10. Which chemical substance is labeled C?
1. a lipid
2. a dipeptide
3. a disaccharide
4. a nucleotide
11. Which substance is represented by letter D?
1. water
2. salt
3. ammonia
4. carbon dioxide
12. Molecule C belongs in the general class of substances known as
1. vitamins
2. minerals
3. inorganic acids
4. organic compounds
Nucleic Acids
Like proteins, nucleic acids are very large molecules.
The nucleic acids are composed of smaller units
called nucleotides. Each nucleotide contains a
carbohydrate molecule, a phosphate group, and a
nitrogen-containing molecule that because of its
properties is a nitrogenous base.
Living organisms have two important nucleic acids.
One type is deoxyribonucleic acid, or DNA. The
other is ribonucleic acid, or RNA. DNA is found
primarily in the nucleus of the cell, while RNA is
found in both the nucleus and the cytoplasm, a
semi-liquid substance that composes the foundation
of the cell.
DNA and RNA differ from one another in their
components. DNA contains the carbohydrate
deoxyribose, while RNA has ribose. In addition,
DNA contains the base thymine, while RNA has
uracil.
1. a. Where is DNA found in the cell?
b. Where is RNA found in the cell?
2. What is one important function of nucleic acids?
3. What are the building blocks of nucleic acids?
Draw a nucleotide, the building blocks of genetic information, in the space provided:
4. Explain the differences between DNA and RNA.
Proteins
Proteins are macromolecules that contain nitrogen as well as carbon,
hydrogen, and oxygen. Proteins can be found in food such as meats,
cheeses, milk, and peanut butter.
Proteins are polymers of molecules called amino acids. There are more
than 20 different amino acids found in nature.
The instructions for arranging amino acids into many different proteins
are stored in DNA in the nucleus. This information leaves the nucleus in
the form of RNA so it can be brought to the ribosomes. When in the
ribosomes, the RNA allows for protein synthesis to occur.
Each protein has a specific role. Their function is determined by their shape. An example of this
are the receptors located on the cell membrane. These receptors can only bind with specifically
shaped messengers.
1. List two examples of proteins.
2. What are the building blocks of proteins?
3. The process of protein synthesis involves two organelles.
a. This organelle is where the DNA is located
b. This organelle is where protein synthesis takes place
4. Explain why the shape of a protein is important.
6. The shape of a protein molecule is influences by
1. whether it is organic or inorganic
2. the number of genes found in the nucleus
3. the sequence of amino acids in it
4. the number of chromosomes in the cell
7. Molecules such as receptors, antibodies, and enzymes, which are composed of chains of amino
acids, are examples of
1. proteins
2. carbohydrates
3. lipids
8. In the diagram, which number indicates a carboxyl group?
1. 1
2. 2
3. 3
4. 4
4. nucleic acids