BSC 108 University of Alabama
Study Guide for Exam 3
Modules 9, 10, 11, 12
Module 9: Essential Biology chapter 10
1. Understand the structure of a strand of DNA
(deoxyribonucleic acid): how it is composed nucleotide
subunits. Know that it has a sugar-phosphate backbone
(made of a sugar called deoxyribose and a phosphate group)
covalently bonded to nitrogen-containing bases.
Both DNA and RNA are nucleic acids consisting of long
chains (polymers) of chemical units (monomers) called
nucleotides. Nucleotide polymer- polynucleotide- can be
very long and have any sequence of the 4 diff types of
nucleotides (abbreviated A, C,T,G). A molecule of DNA
contains 2 polynucleotides, each a chain of nucleotides.
Each nucleotide consists of a nitrogenous base, a sugar
(blue) and a phosphate group (gold)
2. Understand that a DNA molecule contains two strands of
DNA; understand how these two strands form a double helix;
understand how the strands are complementary.
Each base has protruding chem. Groups that best form
hydrogen bonds with only one appropriate partner.
Adenine- thymine; guanine-cytosine (complementary_
3. Know that the nitrogen-containing bases (adenine,
guanine, thymine, and cytosine) of the two strands are held to
each other by hydrogen bonds.
Nitrogenous bases are basic (high pH opposite of acidic).
It has a ring of nitrogen and carbon atoms with various
chemical groups attached.
4. Know that adenine always pairs with thymine and cytosine
always pairs with guanine (A=T and G≡C).
Thymine and Cytosine are single-ring structures. Adenine
and Guanine are larger, double ring structures. Instead of
,thymine, RNA has a base called uracil. Has different
sugar than DNA (ribose instead of deoxyribose). But they
have same chemical structure/
5. Understand how a molecule of DNA replicates; how one
parent molecule that has two complementary strands
separates; how each strand is used as a template to make a
new strand; how each of the two daughter molecules will be
composed of one “old” (parent) strand and one “new” strand.
Two strands of parental DNA separate and becomes a
template for the assembly of a complementary strand
from supply of free nucleotides. Nucleotides line up one
at a time based on pairing. Enzymes link nucleotides to
form new DNA strands. New molecules are Daughter DNA
molecules
6. Know how the two parent strands separate at the origin of
replication; how synthesis of two new complementary strands
occurs in the replication bubble using the parent strands as
templates; how the replication bubbles merge as DNA
replication progresses in both directions at the replication
forks.
Replication results in 2 daughter DNA molecules
consisting of one old and one new strand.
DNA polymerases are the enzymes that make covalent
bonds between the nucleotides of a new DNA strand.
Replication begins on a double helix at specific sites
(origins of replication). Replication proceeds in both
directions called bubbles. Parental DNA strand opens up
as daughter strands elongate on both sides. All bubbles
merge and yield 2 completed double stranded daughter
DNA.
7. Understand how an organism’s DNA leads to specific traits
by dictating the synthesis of proteins.
, DNA specifies the synthesis of proteins. DNA dispatches
instructions in form of RNA which programs protein
synthesis. “Transcription”- transfer of genetic info from
DNA into RNA, “translation”- transfer of info from RNA
into polypeptide (protein strand). The relationship bt
genes and proteins is information flow. Function of DNA
is to dictate production of a peptide.
8. Know the structure of RNA and understand that RNA is a
single-stranded nucleic acid; know that RNA contains uracil
instead of thymine; know that RNA contains the sugar ribose
instead of deoxyribose.
9. Know the functions of the three types of RNA (mRNA,
tRNA, and rRNA); Ribosomes are organelles in cytoplasm
to coordinate functioning of mRNA and tRNA to make
polypeptides. (rRNA)
mRNA (messenger)- prokaryote cells (lack nuclei), RNA
transcribed from a gene functions as this. This is
translated into a protein (not in eukaryotic cells)
introns- internal noncoding regions
exons- coding regions (parts of gene that are
expressed)
RNA splicing- cutting and passing process (before
RNA leaves nucleus, introns are removed, exons are
joined to produce mRNA molecule w continuous coding
sequence)
tRNA- to convert codons of nucleic acids to amino acid
words of proteins, cell uses molecule interpreter (tRNA).
Matches amino acids to appropriate codons to form new
polypeptide. They 1. Pick up appropriate amino acids and
2. Recognize appropriate codons in mRNA. Their unique
structure enables them to perform both functions.
Made up of single strand of RNA (1 polypeptide chain
w 80 nucleotides) @ 1 end of folded molecule is special
Study Guide for Exam 3
Modules 9, 10, 11, 12
Module 9: Essential Biology chapter 10
1. Understand the structure of a strand of DNA
(deoxyribonucleic acid): how it is composed nucleotide
subunits. Know that it has a sugar-phosphate backbone
(made of a sugar called deoxyribose and a phosphate group)
covalently bonded to nitrogen-containing bases.
Both DNA and RNA are nucleic acids consisting of long
chains (polymers) of chemical units (monomers) called
nucleotides. Nucleotide polymer- polynucleotide- can be
very long and have any sequence of the 4 diff types of
nucleotides (abbreviated A, C,T,G). A molecule of DNA
contains 2 polynucleotides, each a chain of nucleotides.
Each nucleotide consists of a nitrogenous base, a sugar
(blue) and a phosphate group (gold)
2. Understand that a DNA molecule contains two strands of
DNA; understand how these two strands form a double helix;
understand how the strands are complementary.
Each base has protruding chem. Groups that best form
hydrogen bonds with only one appropriate partner.
Adenine- thymine; guanine-cytosine (complementary_
3. Know that the nitrogen-containing bases (adenine,
guanine, thymine, and cytosine) of the two strands are held to
each other by hydrogen bonds.
Nitrogenous bases are basic (high pH opposite of acidic).
It has a ring of nitrogen and carbon atoms with various
chemical groups attached.
4. Know that adenine always pairs with thymine and cytosine
always pairs with guanine (A=T and G≡C).
Thymine and Cytosine are single-ring structures. Adenine
and Guanine are larger, double ring structures. Instead of
,thymine, RNA has a base called uracil. Has different
sugar than DNA (ribose instead of deoxyribose). But they
have same chemical structure/
5. Understand how a molecule of DNA replicates; how one
parent molecule that has two complementary strands
separates; how each strand is used as a template to make a
new strand; how each of the two daughter molecules will be
composed of one “old” (parent) strand and one “new” strand.
Two strands of parental DNA separate and becomes a
template for the assembly of a complementary strand
from supply of free nucleotides. Nucleotides line up one
at a time based on pairing. Enzymes link nucleotides to
form new DNA strands. New molecules are Daughter DNA
molecules
6. Know how the two parent strands separate at the origin of
replication; how synthesis of two new complementary strands
occurs in the replication bubble using the parent strands as
templates; how the replication bubbles merge as DNA
replication progresses in both directions at the replication
forks.
Replication results in 2 daughter DNA molecules
consisting of one old and one new strand.
DNA polymerases are the enzymes that make covalent
bonds between the nucleotides of a new DNA strand.
Replication begins on a double helix at specific sites
(origins of replication). Replication proceeds in both
directions called bubbles. Parental DNA strand opens up
as daughter strands elongate on both sides. All bubbles
merge and yield 2 completed double stranded daughter
DNA.
7. Understand how an organism’s DNA leads to specific traits
by dictating the synthesis of proteins.
, DNA specifies the synthesis of proteins. DNA dispatches
instructions in form of RNA which programs protein
synthesis. “Transcription”- transfer of genetic info from
DNA into RNA, “translation”- transfer of info from RNA
into polypeptide (protein strand). The relationship bt
genes and proteins is information flow. Function of DNA
is to dictate production of a peptide.
8. Know the structure of RNA and understand that RNA is a
single-stranded nucleic acid; know that RNA contains uracil
instead of thymine; know that RNA contains the sugar ribose
instead of deoxyribose.
9. Know the functions of the three types of RNA (mRNA,
tRNA, and rRNA); Ribosomes are organelles in cytoplasm
to coordinate functioning of mRNA and tRNA to make
polypeptides. (rRNA)
mRNA (messenger)- prokaryote cells (lack nuclei), RNA
transcribed from a gene functions as this. This is
translated into a protein (not in eukaryotic cells)
introns- internal noncoding regions
exons- coding regions (parts of gene that are
expressed)
RNA splicing- cutting and passing process (before
RNA leaves nucleus, introns are removed, exons are
joined to produce mRNA molecule w continuous coding
sequence)
tRNA- to convert codons of nucleic acids to amino acid
words of proteins, cell uses molecule interpreter (tRNA).
Matches amino acids to appropriate codons to form new
polypeptide. They 1. Pick up appropriate amino acids and
2. Recognize appropriate codons in mRNA. Their unique
structure enables them to perform both functions.
Made up of single strand of RNA (1 polypeptide chain
w 80 nucleotides) @ 1 end of folded molecule is special
