DNA, RNA, and Protein Synthesis Notes
Biology 5.0
Name:
Date:
Activating Prior Knowledge:
1. List the eight characteristics of living things.
2. List the five elements found in nucleic acids.
3. Name the monomer of nucleic acids.
4. Identify the three parts of the monomer mentioned in question three.
5. Name two examples of nucleic acids.
6. Identify two differences between prokaryotic and eukaryotic cells.
7. Which organelle serves as the site of protein synthesis?
8. Name the monomers of proteins.
9. Which organelle modifies, sorts, and packages proteins?
10. Which organelle serves as an intracellular highway?
Period:
The Structure of DNA
___________________________________ is a polymer formed from units called ________________
 Each nucleotide monomer is made of three parts:
a)
b)
c)
 There are four nitrogenous bases found in DNA:
A. Purines (2 ring nitrogen base)
a)
b)
B. Pyrimidines (single ring base)
a)
b)
 The DNA polymer looks like a twisted ladder, with the _____________________ and
__________________________________ making up the sides of the ladder and the
_______________________________ are the steps/rungs.
 Nitrogen bases pair according to certain rules:
a)
b)
 The nitrogen bases are held together by ___________________ bonds.
DNA Replication

Because each of the two strands of the DNA double helix has all of the information to reconstruct the other
half, the strands are said to be ___________________________.

Each strand of the double helix of DNA serves as a ________________ to make the other strand.

For example, if one side of the DNA had the base sequence
A T C C G A T G A T T
The complementary strand would read as follows:
__________________________
 DNA replication is carried out by a series of ____________________
a) they separate ( ______________ ) the two strands of the double helix
b) __________________________ adds new nucleotide
 Illustrate the process of semi-conservative replication below:
RNA
____________________________________________________
 Consists of a long chain of macromolecules made up of _______________________
a)
b)
c)
 3 differences between DNA and RNA:
1)
2)
3)
 3 main types of RNA:
1)
2)
3)
__________________
__________________
__________________
RNA Synthesis: Transcription
__________________________________________________________________________________________

All 3 types of RNA are synthesized from DNA in the _________________ and then used to synthesize
proteins in the ________________________.

Protein synthesis is a two step process:
1)
2)

___________ must bring the genetic information from DNA in the nucleus to the ribosome in the
cytoplasm.

An enzyme, _______________________________ , attaches to the DNA molecule and separates the double
helix.

The enzyme moves along the DNA molecule and synthesizes a ___________________ mRNA strand.
 Transcribe the given DNA sequence into a complementary mRNA:
ATGCAAGTCATTCCAGCT
__________________________________
 The process of transcription takes place in the ______________________.
 The mRNA must be processed before leaving the nucleus.
1)
2)
3)
 Introns:
 Exons:
Ribosomes and Protein Synthesis
 The information that DNA transfers to mRNA is in the form of a code, which is
determined by the way in which the four nitrogenous bases are arranged in DNA.
 DNA directs the formation of _____________________.
 The monomers of proteins are _________________________.
 There are ______ different amino acids.
 A _________________ bond holds two amino acids together.
 The mRNA produced in the _______________ during ___________________
travels to the __________________ to begin the process of _____________________.
 Once at the ribosome, the mRNA is read ______ nucleotides at a time.
 A __________ is a combination of three sequential nucleotides on _________
 There are ________ different codons.
 Each codon specifies a particular ____________________ that is to be placed
in the polypeptide chain.
 ______ is the “initiator” codon.
 There are ______ “stop” codons.
 Translation involves __________, __________, and _________.
 ______________________ carries the amino acids to the ribosome.
(different tRNA for each amino acid)
 ______________________ makes up the major part of the ribosome.
 Three sequential nucleotides on a tRNA molecule are called an
___________________.
 The anticodon on the ___________ is complementary to the codon
of ___________.
UAG CUG AAU CGC
AUC GAC UUA GCG AAU CAG GAU
 Each codon & anticodon bind together, and a __________________ forms between the
two amino acids.
 The polypeptide chain continues to grow until the ribosome reaches a
_________________________.
 A stop codon is a codon for which no __________ molecule exists.
 The ____________________ releases the newly formed polypeptide.
DNA, RNA, and Protein Synthesis Review Questions
Day One
Day Three
Day Two
Day Four
Biology Keystone Exam Preparation
DNA, RNA, and Protein Synthesis
1. Four different segments of a DNA molecule are represented below.
This is an error in the DNA molecule in
a. Segment 1 only
c. Segments 2 and 3
b. Segment 3 only
d. Segments 2 and 4
2. The diagram below represents a portion of a DNA molecule
The letters represent different types of
a. sugar molecules
b. molecular bases
c. enzymes
d. proteins
3. Part of a molecule found in cells is represented below
Which process is most directly affected by the arrangements of components 1 through 4?
a. diffusion through cell membranes
b. fertilization of a sex cell
c. sequencing of amino acids in cells
d. increasing the number of cells in an organism
4. The weakest bonds in a double-stranded deoxyribonucleic acid molecule exists
between
a. deoxyribose sugars
c. nitrogenous bases
b. phosphate groups
d. 5-carbon sugars
5. One similarity between DNA and messenger RNA molecules is that they both contain
a. the same sugar
b. genetic codes based on sequences of bases
c. a nitrogenous base known as uracil
d. double-stranded polymers
6. If 15% of a DNA sample is made up of thymine, T, what percentage of the sample is
made up of cytosine, C?
a. 15%
b. 70%
c. 35%
d. 85%
7. The diagram below represents levels of organization within a cell of a multicellular
organism.
The level represented by X is composed of
a. 4 types of base subunits
b. folded chains of glucose molecules
c. 20 different kinds of amino acids
d. complex, energy-rich inorganic molecules
8. Which sequence best represents the relationship between DNA and the traits in an
organism?
(a)
(b)
(c)
(d)
Base your answers to questions 9 through 10 on the information below and on your knowledge of biology.
DNA samples were taken from three different species and used to determine the amino acid sequence for a
portion of a particular protein. The amino acids were then compared in order to determine which species were
most closely related. Some of the information is shown in the table below.
9. Using the information given, fill in the missing mRNA base sequences in the table for
species B and species C.

Species B
_______________________

Species C
_______________________
10. Using the Genetic Code Chart on the following page, fill in the missing amino acid
sequences in the table for species A and species B.

Species A
______________________

Species B
______________________
11. State one specific effect on the protein produced if an mRNA code is changed from AGU to AGA.
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________