TEST DATE: __________
NAME:
Regents Biology
Homework Packet
Unit 4: Biochemistry

Use your Biology by Miller & Levine textbook to complete and help with the following homework
assignments.

(1) Read the assigned pages, (2) Define the vocabulary, and (3) Answer the questions.

Neatness counts. Number the definitions. Write the page and number of the questions. Do your work in
ink or even type the homework. Staple the definitions and questions to the HW packet.

The homework assignment is due the day before the test. We will use the HW packet as a test review.
The completed and corrected HW packet will be collected on the day of the test. Late homework
assignments receive no credit (0). If the assignment is not turned in by the last day of the quarter the
zero grade (0) will change to -5.
Chapter 2: The Chemistry of Life
Read pgs. 32 - 59
p. 34 Vocabulary (11)
p. 40 Vocabulary (12)
p. 45 Vocabulary (9)
p. 50 Vocabulary (7)
Additional vocabulary (6):
denature peptide bond
glycogen
p. 38 #1a
p. 44 #1b, 3a
p. 49 #2a, 2b
p. 53 #1a, 3a, 3b, 3c
Regents Review
pgs. 56 – 59
#1 - 21
glucose
starch
cellulose
Biochemistry
The chemicals of Living Organisms
Basic Chemistry:
___________ : the smallest unit of matter; protons
distinguish the element (specific type of atom); electrons
determine how the atom acts.
Specific Elements:
Element
Symbol
Bonds
1.
H
2.
O
3.
N
4.
C
MOLECULES / COMPOUND: specific combinations of atoms; combine together by sharing
electrons; make covalent bonds (lines between the letters). Chemical bonds store ________________.
____________ – H2O
_______________ – CO2
_______________ – C6H12O6
Inorganic Compounds: Simple molecules that do not contain
__________ and __________ in the same molecule. Organic
Compounds contain carbon and hydrogen together in the same molecule.
Polymers: are ________ _________ __________ units. Many organic compounds are polymers of
smaller repeating units. They are made by the process of _____________________________
and broken down by _____________________________.
For Example: Many carbohydrates are polymers of glucose. The glucose molecules
are chemically combined and form new molecules with completely different properties. The
hexagon represents glucose and they are combined together with O
(oxygen between the sub units)
Proteins are polymers of amino acids. Then the proteins form
different shapes.
Carbohydrates
____________________ : are simple
sugars; they are the basic building
blocks of all carbohydrates
_____________________ : are
combinations of 2 monosaccharides
Examples: Maltose and Sucrose
Combine molecules by the process of
DEHYDRATION SYNTHESIS
In dehydration synthesis 2 __________ and 1 __________ atoms are removed from the molecules. It makes
room for the two molecules to bond to each other.
C6H12O6 + C6H12O6  C12H22O11 + H2O
C6H12O6 + C6H12O6 = C12H24O12
minus water
H2O
C12H22O11 + H2O
Since H2O came out as a product it was removed from the
original molecules. That is why it is dehydration synthesis,
water was taken out of the reactant molecules.
Notice the # of atoms of each element is the same on both sides; it is a balanced equation (more of that in chem).
Hydrolysis is the process that _________ molecules. It is the exact opposite of Dehydration Synthesis, instead
of taking away water; water is used to break down atoms. Enzymes break the bond holding the two molecules
together and 2 hydrogen and 1 oxygen are added to keep the molecules separated.
Polysaccharides: are _______________, they are long polymers of
monosaccharides; Starches are insoluble in water and thus can serve as storage
depots of glucose. Plants convert excess glucose into starch for storage. The
image shows starch grains (lightly stained with iodine) in the cells of the white
potato. Rice, wheat, and corn are also major sources of starch in the human diet.
Animals store excess glucose by polymerizing it to form glycogen.
Examples of Starches: Cellulose, Chitin, Amylose
Carbohydrates always have a specific ratio between the Hydrogen and Oxygen, 2 Hydrogen : 1 Oxygen.
Does that remind you of any other molecules?
Carbohydrates provide the bulk of the ______________ (4 kcal/gram) in most diets.
Lipids
Fats, Oils, Waxes that are used to store energy
Made from 1 Glycerol molecule and 3 Fatty Acids
___________ = 3 Carbon chain with hydroxide groups (OH) attached to each carbon.
__________________ = Long chains of Carbon and Hydrogen atoms with an acid group (carboxyl group) at
the end (-COOH).
______________ Fatty Acids
have single bonds between the
carbon atoms
______________ Fatty Acids
have double or triple bonds
between the carbons
______________ fats, the good
fats for you; have many double
and triple bonds
Like polysaccharides, Lipids are made through the same process, Dehydration Synthesis. In this instance it
happens 3 times to attach each of the fatty acids.
The reverse process
is also true. Lipids
are broken down by
the process of
_______________.
It is just the same
formula but turn
the arrow around.
If you really wanted to, you could count the number and type of atoms before and after the reaction. What will
be true about those numbers?
Lipids chiefly function in _________________ (9 kcal/gram), protection, and insulation. They contain carbon,
hydrogen, and oxygen but the H:O is not in a 2:1 ratio (Like Carbohydrates). Lipids tend to be large molecules.
fats  found chiefly in animals
oils and waxes  found chiefly in plants - oils are liquid at room temperature, waxes are solids
lipids along with proteins are key components of _________ _________________
steroids are special lipids used to build many reproductive hormones and cholesterol
Proteins
Make up the structure, enzymes, and characteristics of organisms
________________ = are the building blocks of all proteins. There are 20 different essential amino acids. All
the proteins in your body
Alanine
Arginine
Asparagine
Aspartic Acid
(billions of them) are
Carnitine
Citrulline
Cysteine
Cystine
made from different
Gaba
Glutamic
Acid
Glutamine
Glutathione
combinations of these
Glycine
Histidine
Isoleucine
Leucine
essential amino acids.
Lysine
Methionine
Ornithine
Phenylalanine
ProlineSerine
Taurine
Threonine
Tryptophan
All amino acids have the
Tyrosine
Valine
same basic structure, an
amino group, an acid
group, and a variable chain (R) in the middle.
*Notice the CH3. That
variable group makes
this amino acid Alanine.
For each of the 20
essential amino acids
the variable group is
composed of different
atoms.
Peptides
Peptides are chains of amino acids. The amino acids are held together by peptide bonds, a bond between the
nitrogen atom in the amino group to the carbon atom in the carboxyl group. They are created by the process of
D
S
and broken down by H
The order of amino acids determines the shape of the peptide. When peptides come together proteins are
formed. The shape of the protein determines the proteins function.
Proteins are used for structure and function (bones and muscles), enzymes, antibodies, hormones, buffers
(stabilize pH), and pigments. The proteins in your body make up your characteristics
Enzymes
Enzymes are __________________________ that are organic catalysts.
Organic Catalysts are molecules that __________________ the rates of reactions.
Most enzyme names end in –ase.
Enzymes lower the energy needed to start a chemical reaction. (activation energy)
It is thought that, in order for an enzyme to affect the rate of a reaction, the following events must take place.
1. The enzyme must form a temporary association with the substance or substances whose reaction rate it
affects. These substances are known as substrates.
2. The association between enzyme and substrate is thought to form a close physical association between
the molecules and is called the enzyme-substrate complex.
3. While the enzyme-substrate complex is formed, enzyme action takes place.
4. Upon completion of the reaction, the enzyme and product(s) separate. The enzyme molecule is now
available to form additional complexes.
** Although enzymes may be reused in cells, they eventually are destroyed and new ones must be
synthesized.
________________________:
A substrate is the molecule(s) that the enzyme acts on. Enzymes can build up or break down molecules. In the
end of the reaction the substrate becomes the product.
________________________:
The active site is the specialized area on
the enzyme that comes in contact with the
substrate.
________________________:
Coenzymes are molecules that attach to
enzymes to make them work better.
Usually coenzymes are vitamins and
minerals.
Enzyme Action
1. Lock and Key Model - each
enzyme is specific for one and ONLY one substrate (one lock one key). In this theory the enzyme and substrate fit exactly
together. It is the easier way to think of the situation.
2. Induced Fit Model – enzymes have the ability to
change shape to fit around the substrate. This theory allows
enzymes to work on multiple substrates.
Factors that Affect Enzyme Action
1. ______ - the optimum (best) in most living things is close to 7 (neutral). High or low pH levels
usually slow enzyme
1. At what pH level does the enzyme
activity.
pepsin (a protein enzyme) seem to work
best?
2. At what pH level does the liver enzyme
seem to work best?
3. What would happen if you took a lot of
Pepto-Bismol to help reduce your stomach
acid?
4. One of the many things that our liver
enzymes do is to break down toxins.
Toxins are poisons in our bodies. What
would happen if your liver pH increased?
Would your health be affected?
5. So...what does this tell you about
enzyme activity and pH?
2. ___________________ - strongly influences enzyme activity.
Optimum temperature for maximum enzyme function is usually about 3540 C. Reactions proceed slowly below optimal temperatures. Above optimal temperatures, around 45 C in
humans, most enzymes are _____________ (change in their shape so the enzyme active site no longer fits with
the substrate and the enzyme can't function).
1. What happens to the
enzyme catalase when it is
exposed to high temperatures?
2. What happens to the
enzyme lactase when it is
exposed to high temperatures?
3. So...what does this tell you
about enzyme activity and
temperature?
3. ____________________________________ - When there is a fixed amount of enzyme and an excess
of substrate molecules -- the rate of reaction will increase to a point and then level off. This leveling off occurs
because all of the enzymes are used up and the excess substrate has nothing to combine with. If more enzyme is
available than substrate, a similar reaction rate increase and leveling off will occur. The excess enzyme will
eventually run out of substrate molecules to react with.
Nucleic Acids
DNA and RNA
Nucleic acids are the instructions to make peptides.
________________________ : are the
subunits of nucleic acids.
_____________________: are long
chains of nucleotides.
1. ______: Ribonucleic Acid
RNA is a single strand of
nucleotides. It is found in the
nucleus, ribosomes, and the
cytoplasm of cells. The
nucleotides sometimes bind with
complimentary pairs, C-G and AU. The primary role of RNA is to
carry the genetic message from
the nucleus to the ribosome for
the production of peptides (protein
synthesis).
2. _____: Deoxyribonucleic Acid
DNA is a double strand of
nucleotides (double helix). The
nucleotides bond together in
complimentary pairs, A-T, and CG. It is found inside the nucleus of
cells. It can also be found inside
chloroplasts and mitochondria. It
carries the genetic information and
controls the cell’s activities.
Every nucleotide is made up of three different parts.
1. _____________ group = PO4
2. ____________
in DNA the sugar = ________________
in RNA the sugar = ________________
3. ________________ = Nitrogen contain molecule, makes
each nucleotide different
1. ____________ (G)
2. ____________ (C)
3. ____________ (A)
4. ____________ (T)  only found in DNA
5. ____________ (U)  only found in RNA
Organic
Compound
Carbohydrates
Lipids
Proteins
Nucleic Acids
Elements
Subunit
Structure
Function
Example
Understand the Concepts
1. Distinguish between a solute and a solvent.
2. Balance the following equation: ___ CO2 + ___ H2O  ___ C6H12O6 + ___ O2
3. Distinguish between a structural formula and a molecular formula.
4. What might be the result of mixing two solutions of equal volume, one of which has a pH of 9 and
the other, a pH of 5?
5. Why do atoms share electrons?
6. Name the three types of atomic particles and describe where each is found in the atom.
7. What do you think a "double" covalent bond is?
8. Why are a hydrogen and hydroxyl(OH) removed during a dehydration synthesis reaction?
9. Why are a hydrogen and hydroxyl necessary for hydrolysis?
10. Why can organic molecules get so large?
11. How is a peptide bond formed?
12. How are the two chains of a double helix held together?
13. Why are small amounts of enzymes sufficient to catalyze a large number of chemical reactions?
14. Explain how glucose, fructose, and galactose can be different molecules even though they all
have the same molecular formula (C6H12O6).
Covalent bonding between Oxygen and Hydrogen
1. In a covalent bond atoms share
pairs of __________.
2. How many electron vacancies does
an atom of hydrogen have?___
3. How many bonds can hydrogen
make?___
4. How many electron vacancies does
oxygen have?___
5. How many bonds can oxygen
make?___
6. How many atoms of hydrogen
bond to oxygen to form water?___
7. What is the chemical formula of
water?__________
Dehydration Synthesis of a Lipid
Dehydration Synthesis of a Peptide
Know the Terms
Select the most appropriate words from the list to complete the following paragraphs.
nucleic acids
hydrolysis
polysaccharide
fatty acids
enzymes
organic compounds
monosaccharides
thymine
hydrogen
lipids
deoxyribose
carbohydrates
adenine
disaccharide
DNA
dehydration synthesis
cytosine
peptide bond
oxygen
glycerol
carbon
ribose
amino acids
proteins
saturated
guanine
RNA
unsaturated
Living organisms are composed of a special category of molecules called _______________(1). Molecules must
have both _______________(2) and _______________(3) atoms in them to be in this category. In addition they usually
contain _______________(4) as well.
Sugars and starches are _______________(5), which always have a hydrogen to oxygen ratio of 2:1. They are
composed of building blocks called _______________(6). Two of these units can be attached to each other through a
process called _______________(7), which results in a _______________(8). If more subunits are hooked on, we get a
_______________(9). This type of molecule can be broken into its building blocks again through the reverse reaction,
called _______________(10).
_______________(11) have a hydrogen to oxygen ratio greater than 2:1 and include fats, oils, and waxes. If the
carbon-to-carbon bonds in these molecules are all single bonds, they are said to be _______________(12). lf there are
any double bonded carbons, the molecule is said to be _______________(13).The building blocks of these molecules are
_______________(14) and _______________(15).
The group of organic molecules that contain nitrogen are called _______________(16). They have
_______________(17) as their building blocks. The bond connecting two of these together is called a _______________
(18). Some of these molecules function as _______________(19), which catalyze chemical reactions within cells.
The group of organic molecules that were first discovered in the nucleus of the cell are called _______________
(20). There are two kinds of these molecules. They are _______________(21) and _______________(22). One of these
is described as a double helix. Its subunits are composed of a five-carbon sugar, called _______________(23), and one
of four bases.
MATCHTNG QUESTIONS
From the list below, select the term that best fits each of the following descriptions. Each term may be used more than once, but there
is only one correct answer for each question.
a. radioactivity
b. suspension
c. acid
d. neutralization
e. solvent
f. indicator
g. fatty acid
h. hydrolysis
i. saturated
j. nucleic acid
k. enzyme
l. peptide bond
m. starch
n. ribose
o. substrate
p. coenzyme
q. denaturation
r. amino group
___ 1. the reaction between an acid and a base
___ 9. splitting apart molecules by reacting with water
___ 2. having no carbon-carbon double bonds
___ 10. a component of RNA
___ 3. formed between two amino acids
___ 11. the bulk component of a solution
___4. mixture that separates on standing
___ 12. a part of a lipid molecule
___ 5. an organic catalyst
___ 13. produces H ions in solutions
___ 6. RNA and DNA
___ 14. that upon which an enzyme acts
___ 7. changes color with change in pH
___ 15. change in structure that can be caused by heating
___ 8. a polymer of glucose
MODIFIED TRUE FALSE
Indicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the sentence or
statement true.
____
1. The basic unit of matter is the molecule. _________________________
____
2. A substance made up of only one kind of atom is a(an) element. _________________________
____
3. Scientists show the composition of compounds by a kind of shorthand known as a chemical formula.
____________________
____
4. The compound produced by a reaction between an acid and a base is an alkaline solution.
_________________________
____
5. Lipids are important parts of biological membranes and waterproof coverings. _________________________
____
6. Polysaccharides are formed through the process known as polymerization. _________________________
____
7. The substances that are present when a chemical reaction begins are the products. _________________________
____
8. Proteins that speed up the rate of chemical reactions in the cell without requiring high temperatures are antibodies.
_________________________
MULTIPLE CHOICE QUESTIONS
Choose the best answer and write it on the answer blank.
___ 1. A covalent bond is formed as the result of
a.) transfer of electrons
b.) transfer of protons
c.) sharing of an electron pair
d.) sharing of a proton pair
___ 12. The main function of glucose is
a.) to function as an enzyme
b.) to assist in protein synthesis
c.) to be part of nucleic acids
d.) as a source of energy
___ 2. In chemical reactions, atoms are
a.) created
b.) rearranged
c.) destroyed
d.) neutralized
___ 13. Which of the following organic compounds is the main
source of energy for living things?
a.) carbohydrates
b.) lipids
c.) nucleic acids
d.) proteins
___ 3. lf the pH of an acid solution and a basic solution were
checked
a.) both would be below 7
b.) both would be above 7
c.) the acid solution would be above 7; the basic solution would
be below 7
d.) the acid solution would be below 7; the basic solution would
be above 7
___ 4. The total number of carbon atoms in the compound
2C6H12O6is
a.) 2
b.) 6
c.) 12 d.) 24
___ 5. When hydrogen and oxygen combine to form water,
hydrogen would be a(n)
a.) product
c.) ionic bond
b.) reactant
d.) radioisotope
___ 6. Which of the following is an inorganic compound?
a.) carbohydrate
c.) water
b.) amino acid
d.) enzyme
___ 7. All the following statements about enzymes are true
EXCEPT
a.) Enzymes work best at a specified pH.
b.) All enzymes work inside cells.
c.) Enzymes are proteins.
d.) Enzymes are organic catalysts.
___ 8. RNA and DNA differ from each other in that
a.) RNA has guanine but DNA does not
b.) DNA is single stranded but RNA is not
c.) DNA has ribose but RNA has deoxyribose
d.) RNA has uracil but DNA does not
___ 9. Amino acid is to protein as
a.) fat is to lipid
b.) DNA is to RNA
c.) sugar is to fat
d.) sugar is to starch
___ 10. A monosaccharide is a
a.) carbohydrate
c.) nucleic acid
b.) lipid
d.) protein
___ 11. Which is NOT a lipid?
a.) fats
c.) waxes
b.) oils
d.) enzymes
___ 14. Which of the following is NOT a function of proteins?
a.) store and transmit heredity
b.) help to fight disease
c.) control the rate of reactions and regulate cell process
d.) build tissues such as bone and muscle
___ 15. Which statement is true?
a.) Simple sugars are made of polysaccharides
b.) Glycerol is made of fatty acids
c.) Glycogen is made of starch
d.) Amino acids are made of proteins
___ 16. Identify the reactant(s) in the chemical reaction,
CO2 + H2O  H2CO3.
a.) CO2, H2O and H2CO3
b.) CO2 and H20
c.) H2CO3
d.) CO2
___ 17. Which statement about organic compounds is
CORRECT?
a.) All contain carbon.
b.) All can be produced in chemistry laboratories'
c.) All contain hydrogen'
d.) They contain most of the 90 elements.
___ 18. Which statement is TRUE?
a.) Sugars are made of polysaccharides.
b.) Glycerol is made of fatty acids.
c.) RNA molecules are made of nucleotides
d.) Amino acids are made of proteins.
___19. Which group of organic compounds includes the
enzymes?
a.) carbohydrates
b.) lipids
c.) proteins
d.) nucleic acids
___20. Which characteristic allows enzymes to function in a
specific way?
a.) Each enzyme has a characteristic shape.
b.) Enzymes are long, complex compounds composed of starch.
c.) Enzymes are long, complex fats.
d.) Each enzyme is made up of sugar, phosphate and base.
___ 21. Which represents an amino acid?
CONSTRUCTED RESPONSE
Answer each of the following questions.
1. What are the structural differences between the two types of nucleic acids?
2. Where are the bases located on a molecule of DNA?
3. Compare what happens to a water molecule during hydrolysis and dehydration synthesis.
4. Compare the lock and key model with the induced-fit model.
5. When your stomach produces excess HCl, you feel a burning sensation.
a. What kind of substance can you use to relieve the stress caused by excess acid?
b. What is the term for the type of reaction that will bring relief?
c. Why does this reaction bring relief?
d. What are the products of this reaction?