Tutorial - Week 2 - nucleotides and nucleic acids Flashcards
Structure = ?
function
label each category
Identify the structure of nucleotides (list the three key structures, their parts, and the roles of nucleotides)
How do nucleotides join to form nucleic acid?
Polymerisation
How does the structure of nucleic acids relate to their function?
Describe the biological function of nucleic acids
Nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), carry genetic information which is read in cells to make the RNA and proteins by which living things function. The well-known structure of the DNA double helix allows this information to be copied and passed on to the next generation
Identify higher-order structures of DNA and RNA
Chromatin is the higher-order structure that encompasses each cell’s genetic blueprint, its DNA. Within chromatin, the DNA is tightly wrapped around histone proteins, which are capable of efficiently fitting the lengthy DNA strands into a relatively small space.
How is DNA transcribed into mRNA and how mRNA is translated into proteins
During transcription, the enzyme RNA polymerase (green) uses DNA as a template to produce a pre-mRNA transcript (pink). The pre-mRNA is processed to form a mature mRNA molecule that can be translated to build the protein molecule (polypeptide) encoded by the original gene.
What is the naming convention for pyrimidines and purines?
Add -idine to the name of a pyrimidine (e.g: cytidine) and -osine to the root name of a purine (e.g: adenosine)
T/F: nucleotides can have more than one phosphate group attached?
What are the naming conventions for those?
Explain the DNA replication process, the mechanism that unwinds the helix, the thing that synthesises short RNA primers, and the one that forms the new strand
Describe the following:
- Chromosome
- Gene
- Nucleic acid
- Genotype
- Phenotype
- Genome
- Transcriptome
Proteome
What is this group of a nucleotide called?
Base
What is this group of a nucleotide called?
Phosphate group
What is this group of a nucleotide called?
Deoxyribose or ribose sugar
What are the roles of the following elements of a nucleotide? Explain
- Nitrogenous base
- Pentose (five-carbon) sugar:
- Phosphate group
Nucleotides have several roles in cellular metabolism, such as…? (3 points)
- energy currency in metabolism (e.g. ATP),
- structural components in enzyme cofactors (e.g. NADPH)
- constituents of nucleic acid
Label
The ______________ are important components of nucleotides, they contain carbon and nitrogen and are
bases because they contain an amino group
nitrogenous bases
Label the type of nitrogenous base these are and name them
Label the type of nitrogenous base these are and name them - include which is present only in RNA and which in DNA
Each nucleotide in DNA contains one of four possible nitrogenous bases: ____________
Each nucleotide in RNA contains one of four nitrogenous bases: _____________
C, T, A and G.
C, U, A and G.
What is pentose considered in lay terms?
The sugar coating
Label these as Deoxyribose and Ribose, what does the orange circle mean?
How many members does the ring have?
What does the carbon numbering determine? determine?
Which one is more stable?
Which group is responsible for the negativity of nucleic acids?
The phosphate group
Name and label the groups and explain their components
T/F: Nucleotides can only have one phosphate group?
What does this look like and how does it change their nomenclature?
False - they can have more than one attached to them
Name this nucleotide
ATP
Name this nucleotide
cAMP
- Nucleotides are acidic or basic?
- Can be cyclic when…?
- NTPs (such as ATP) carry…?
- cAMP and cGMP are important regulators of …?
- acidic
- phosphoric acid is esterified to one of the other available OH groups (e.g. cAMP
and cGMP) - chemical energy
- cellular metabolism
NTP stands for?
nucleoside triphosphate
- Nucleic acids are polymers of __________
- Nucleotides are linked __________ by ________?
- Polynucleotide chains have…?
- Nucleotide chains are read from…?
- nucleotides
- 3’ to 5’ - phosphodiester bonds
(the 5’ phosphate group is joined to the 3’ OH of the
preceding nucleotide). - a phosphate group at one end
(5’ end) and a OH group attached to the sugar (3’ end) - 5’ to 3’
What are the levels of DNA structure?
In Primary structure: the order is so important. Why?
- Specifies the genetic code: sequence is information
- 3 letters (bases) = 1 amino acid
ase pairing is very specific and follows…? Explain
Chargaff’s rule:
[purines] = [pyrimidines]
[A]=[T]
[G]=[C]
T/F: Base pairing and H-bonds are very important to hold the complimentary strands
T/F: G-C Pairing is stronger than A-T
True
True
Name all these bases and give the number of bonds between each
Describe secondary structure (7 points)
Describe tertiary structure. 1 main point and imagine the shapes of the result
Describe quarternary structure:
- In Eukaryotes DNA is complexed with
_______________ to form _________ - Histones are…?
- What is the nucleosome?
- positively-charged proteins. chromatin
- (positive proteins)
- DNA (negative) wrapped around
8 histones (positive)
* 150 base pairs are in contact with the proteins
* Packaged into chromosomes and safely
located inside the nucleus
Why is DNA structure so important?
Describe the process (4 steps) of DNA replication
- DNA helix is denatured to allow replication
- Each strand of DNA helix acts as a template for new
complementary strand - Semiconservative replication (i.e. each daughter molecule
has one old strand & one new strand) - Dependent on complementary base pairing
DNA Replication:
List and describe the enzymes that allow for the process to occur and what each of them do. Show where on a DNA strand they are located and include the leading and lagging strands
Label
Complete the table
How does the DNA sequence becomes a functioning protein?
What happens during transcription?
The information encoded in DNA is transcribed
into a mRNA molecule in the nucleous
What happens during translation?
- Mature mRNA moves to the cytoplasm
- mRNA is translated into an amino acid
sequence in the ribosomes
List and describe the 3 steps of transcription
What are the three steps of processing pre-mRNA to obtain mature mRNA? Describe
Label
Describe ribosomes (2 points)
- 2 submits, in the cytoplasm
- Subunits join at the initiation of protein synthesis
Ribosomal RNA (rRNA) is part of the ribosomal structure:
- Structural component of _________
- rRNA combines with __________ to form ribosomes
- Helps align ________ and _________
- Helps _________ the mRNA
- Catalyses ___________ formation
- ribosomes
- special proteins
- ribosome and mRNA
- reading
- peptide bond
- tRNA is ___________ with the corresponding
amino acid (AA): - AA is covalently attached via an ____________ at the
3’ end of _______ - _____________ of AA is activated to facilitate
formation of __________ - Link between AA and information in the mRNA is…?
- Codons =
- tRNA with the correct anticodon binds to…?
- aminoacylated
- ester bond. tRNA
- Carboxyl group. peptide bond
- tRNA
- sequences of 3 bases that code for 1 AA
- the mRNA in the ribosome
Protein synthesis:
- Occurs where?
- Peptides are formed by…?
- In the cytoplasm
- linked amino acids with a covalent bond (peptide bond)
_________________ use an inactivated virus/bacterium to induce the
immune system in producing antibodies
Traditional vaccines
______________ use an mRNA transcript from a part of the spike protein at the surface of the virus.
mRNA vaccines
mRNA injected in the patient is translated into a…?
Harmless portion of the spike protein and will trigger the immune system to produce
antibodies that recognise the spike protein
T/F: In mRNA vaccines, when infected with the virus, the antibodies target the virus to be
destroyed by our immune system
True
Key concept: Nucleotide structure (3 points)
- Nitrogenous base
- Pentose
- Phosphate
Key concept: DNA function (3 points)
- Replication
- Transcription
- Storage of genome
Key concept:
DNA vs RNA (4 points)
- Structure
- Function
- Location
- Stability
Key concept: mRNA synthesis, structure & function (2 points)
1.Transcription: DNA is transcribed into a
mRNA molecule
2. Translation: mRNA is translated into a
Protein
Key concept: Protein synthesis: (2 points)
- ribosomes, tRNA, rRNA, mRNA
- codons and amino acids
Key concept: DNA structure (4 points)
- Primary structure: the sequence of N bases (specifies genetic code)
- Secondary structure: 3D conformation (double helix)
- Tertiary structure: supercoiling (in prokaryotes)
- Quaternary structure: wrapping of DNA around histones
Key concept: Nucleic acid: polymers of nucleotides (3 points)
- Nucleotides are linked 3’ to 5’ by phosphodiester bonds
- Polynucleotide chains have a phosphate group at one end
(5’ end) and a -OH group attached to the sugar (3’ end) - In DNA: complementary strands are connected via H-bonds
