BIOS 2150 Microbiology Tuesday 10/9/18
Review Questions
Leading and lagging strands are always referring to the new DNA on the inside
If this is a nucleotide that wants to join a new strand of DNA, which part joins
the new strand? 5’ end (phosphate)
Which part of the nucleotide is going to dock into the parent strand? 3’
nitrogen base
Protein Synthesis – terminology
Recall that proteins are made of amino acids
Triplet - a series of 3 DNA nucleotides that code for 1 amino acid
o If you stack a bunch of triplets together you create a gene
Gene – a long series of nucleotides in a chromosome that codes for 1 protein
The DNA molecule contains hundreds of genes
There is not room within the nucleic acid to create protein
RNA (Section 10.3)
RNA’s job is to help DNA with protein synthesis
A molecule that assists DNA in protein synthesis
RNA = Ribonucleic acid
Contains the sugar ribose, and a phosphate group
The four bases are adenine, uracil, cytosine, and guanine
If RNA bonds to DNA
o RNA – DNA
o A–T
o U–A
o G–C
o C–G
If RNA bonds to another RNA
o A–U
o U–A
o G–C
o C–G
Check your understanding
How do DNA and RNA differ structurally? In cells, RNA is single stranded (*right
now); Uracil instead of thymine; sugar is different
Messenger RNA (mRNA) Section 11.3
Copies a DNA gene
This process is called DNA transcription
Each group of 3 mRNA bases is called a codon
RNA polymerase is the enzyme that builds mRNA
1
Review Questions
Leading and lagging strands are always referring to the new DNA on the inside
If this is a nucleotide that wants to join a new strand of DNA, which part joins
the new strand? 5’ end (phosphate)
Which part of the nucleotide is going to dock into the parent strand? 3’
nitrogen base
Protein Synthesis – terminology
Recall that proteins are made of amino acids
Triplet - a series of 3 DNA nucleotides that code for 1 amino acid
o If you stack a bunch of triplets together you create a gene
Gene – a long series of nucleotides in a chromosome that codes for 1 protein
The DNA molecule contains hundreds of genes
There is not room within the nucleic acid to create protein
RNA (Section 10.3)
RNA’s job is to help DNA with protein synthesis
A molecule that assists DNA in protein synthesis
RNA = Ribonucleic acid
Contains the sugar ribose, and a phosphate group
The four bases are adenine, uracil, cytosine, and guanine
If RNA bonds to DNA
o RNA – DNA
o A–T
o U–A
o G–C
o C–G
If RNA bonds to another RNA
o A–U
o U–A
o G–C
o C–G
Check your understanding
How do DNA and RNA differ structurally? In cells, RNA is single stranded (*right
now); Uracil instead of thymine; sugar is different
Messenger RNA (mRNA) Section 11.3
Copies a DNA gene
This process is called DNA transcription
Each group of 3 mRNA bases is called a codon
RNA polymerase is the enzyme that builds mRNA
1
