Nucleic Acids
What are the three components of a nucleic acid? Draw it out and label carbons.
Phosphate group, sugar, nitrogenous base
What is the central dogma? What is the reactant and product?
Central dogma is the flow of genetic information.
DNA to RNA to Protein
How many nucleotides are in a codon? What does a codon do?
3 nucleotides; 1 codon codes for an amino acid
What is the basic structure of an amino acid?
Central carbon with a hydrogen, carboxyl group (COO-), amino group(NH3+), and r group.
Which grouping determines the shape and function of the protein?
What is complementary base pairing?
1:1 ratio between purines and pyrimidines
Adenine - Thymine/Uracil
Guanine - Cytosine
What is the difference between RNA and DNA?
RNA: Ribonucleotides, contains oxygen, free hydroxyl group, single stranded, Uracil
DNA: Deoxyribonucleotides, no oxygen, free H atom, double stranded, Thymine
What stages are the promoter and terminator used? What do they do?
Promoter: Initiation
-Begins transcription, signals for the sigma factor to bring the RNA polymerase to the DNA strands
Terminator: Termination
-Begins termination and ends transcription, takes the RNA polymerase out of strands, closes the strands back up, ends coding onto the mRNA strand
What is a ribosome made of?
Protein and RNA
What distinguishes a polypeptide from a functional protein?
A polypeptide is the sequence of amino acids, whereas a functional protein is folded into a specific 3D shape
What is a gene?
A sequence of DNA that encodes for a protein
What bases are purines and which are pyrimidines? What is the difference between these two?
Purines: 9 atoms on 2 rings - Adenine and Guanine
Pyrimidines: 6 atoms on 1 ring - Thymine, Cytosine, Uracil
In a replication bubble, which strand is the template and which is the coding? How can you tell this? Which strand has the same code as the mRNA? What is the exception?
Template is next to mRNA, coding is opposite. Coding has same sequence as mRNA except for Uracil/Thymine.
Which end of the tRNA molecule binds to an amino acid? What is this tRNA molecule called?
The 3' end' Aminoacyl tRNA (charged)
What distinguishes polar from nonpolar amino acids?
Polar amino acids have side chains with partially charged groups, whereas nonpolar amino acids have hydrophobic side chains
What bonding creates a sugar-phosphate backbone? What bonding is between nitrogenous bases?
Phosphodiester bonds
Hydrogen bonds
What is polymerization? What structure does it create?
The process of joining together two nucleotides by dehydration synthesis. This creates the sugar phosphate backbone.
What carbons does the sugar-phosphate backbone run along?
What are the modifications found in transcription and functions? Where are they (if applicable)?
Capping: On the phosphate group/5'. Binding and protection.
Tailing: On the hydroxyl group/3'. Stabilization and motility
Splicing: Removes introns and keeps exons
What are the characteristics of the genetic code? Explain each characteristic.
Universal: All living things share the same genetic code
Unambiguous: Codons only code for 1 amino acid (1 codon exclusive to 1 amino acid)
Conservative: Codons share the first two nucleotides and only the third varies when they code for the same amino acid.
Redundant: Multiple codons code for an amino acid (3 different options for an end codon)
What bonding joins amino acids together to form a polypeptide and through what process? What direction are chains written in?
Peptide bonds; Dehydration synthesis; N-terminus to C-terminus
What is the difference between prokaryotic and eukaryotic transcription?
Eukaryotic RNA undergoes modifications (splicing, capping, tailing), prokaryotic RNA does not
What are the levels of complexity for DNA and RNA? Explain how you get from one level to the next.
DNA: Nucleotide, single-strand, double-stranded helix, chromosome, genome
RNA: Nucleotide, single strand, hair pin, tertiary/3D structure
What are the stages of transcription? Be specific on what starts it, what enzymes are used on what strands, and what ends it.
Initiation, elongation, and termination
Begins with promotor sequence, signals for the sigma factor to bring the RNA polymerase to the template strand, codes the mRNA strand by adding nucleotides till it reaches the terminator sequence, then releases RNA polymerase and mRNA and closes back up
What are the stages of translation?
Initiation: When start codon reaches the tRNA anticodon in the A site of the large ribosomal subunit. mRNA, ribosome, and tRNA come together.
Elongation: Polypeptide is formed in the p-site of the large ribosomal subunit as it catalyzes peptide bonds between amino acids to form a chain
Termination: The stop codon reaches the anticodon on the tRNA in the A site. The release factor is enabled and the ribosomes disassociates, tRNA and mRNA are released, and we are left with just the newly formed polypeptide chain.
What stabilizes a primary structure of protein? Secondary structure of protein? Tertiary structure of protein? Quaternary structure of protein?
Primary: Peptide bonds
Secondary: Hydrogen bonds
Tertiary: Hydrogen bonds, hydrophobic interactions/Van Der Waals interactions, disulfide bonds/bridges, ionic bonds
Quaternary: Hydrogen bonds, hydrophobic interactions/Van Der Waals interactions, disulfide bonds/bridges, ionic bonds
What is denaturing? What are factors that cause this?
When a protein unfolds and loses its function/structure. Due to heat, pH change, exposure to chemicals.