Macromolecules
DNA Replication
Transcription
Translation
Miscellaneous
100
Hydrates of Carbon vs Hydrocarbons... describe each and which family they fall in.
Hydrates of Carbon - for every C there's a water... Cn(H2o)n (carboHYDRATES)
Hydrocarbons - a bunch of C's and H's (every C has as many H's as it wants) (Lipids)
100
Which direction does DNA Polymerase III read and add? Where is a new nucleotide added? (Which end and what group?)
Reads 3' -> 5'
Adds 5' -> 3' on the 3' OH group
100
What is a gene?
Genes are a region of DNA that encode for RNA molecules and provide the instructions for making proteins.
100
Which strand of DNA is the same as RNA (except the T's in DNA become U's in RNA)? What is the other DNA strand for?
Coding Stand
Template strand is what RNA Pol II transcribes
100
Translation sometimes gets paused to go to the surface of the ______. Once resumed, it ends up inside which is where posttranslational ___________ occur to complete the protein (often necessary so protein can fold properly).
RER
modifications
200
Describe the structure of amino acids and nucleotides.
Amino Acid:
Nucleotide:
200
What is the origin of replication? What is special about the starting point?
The initial weak point rich in A's and T's
200
What is transcription?
DNA -> RNA
200
What is RNA Processing? Give 3 examples and their functions.
RNA Processing is modifying the pre-mRNA
5' Cap - Protects mRNA from degradation and aids in entry to ribosome
Poly(A) Tail - Protects RNA and aids in transportation
Splicing - Provides diversity of proteins
200
What is chromatin? Euchromatin vs Heterochromatin and chemical modifications associated with each?
DNA wrapped around nucleosomes (made up of histone proteins)
Euchromatin; accessible/looses = acetylation
Heterochromatin; inaccessible/tightens = methylation
300
What are the main macromolecules? What do they do? What kind of bond links them? Polymers are made via what kind of rxn? Which is not a polymer?
Polysaccharides - energy storage and structural support (glycosidic bonds)
Lipids - long-term energy storage and membrane structure (not polymer)
Proteins - They do everything (enzymes, transport, motility, storage, etc) (Peptide bond C-N)
Nucleic Acids - Genetic info (phosphodiester bonds when adding nucleotides to same strand... hydrogen bonds for complementary strand)
Condensation rxn
300
In which direction do the leading and lagging strand go in terms of the replication fork? How are the nucleotides added?
Leading - towards; continuously
Lagging - away; Okazaki fragments
300
In eukaryotes, do transcription and translation happen at the same place of the cell? Where?
No
Transcription occurs in nucleus
Translation - in cytoplasm to encounter ribosomes
300
Why do we have many more proteins than we do genes?
Splicing - allows many different proteins to arise from the same gene/pre-mRNA molecule
Introns are cut out from the primary transcript while exons are kept and spliced together to make the final mRNA molecule that gets transcribed to proteins. There is a variation in which regions are exons and introns which is how we get the diversity of proteins
300
What is one of the most important things about a molecule that allows it to interact with other molecules? What happens when a molecule is chemically modified?
It's shape... which changes once it is chemically modified so these modifications can alter the overall shape and reveal new pockets
Could act as on/off switch
400
Name these structures. Macromolecule family? How many ______ bonds are they involved in and what is their base pair? What molecule are these nucleotides involved in?
Nucleic acids
Hydrogen
Guanine; 3 hydrogen bonds with cystine
Uracil; 2 hydrogen bonds with Adenine
RNA
400
These are the proteins involved in DNA Replication. What is each proteins job? (Only answer for proteins discussed in class)
Helicase opens towards the replication fork
Primase creates small RNA primers
DNA Pol III uses the RNA primer as a starting point to start copying DNA *both leading and lagging strand need the primer)
DNA Pol I removes the RNA primer
DNA Ligase links the Okazaki fragments to make a continuous strand
400
List the benefits of using RNA as an intermediate molecule.
-Protects DNA in the nucleus (ruined = lost genes)
-Many copies of mRNA to be translated at once waiting to be made into proteins
-Ability to edit the mRNA copy to make alternate proteins (splicing)
400
Describe the function of the 3 types of RNA. Which has the codon and anticodon?
mRNA - Carries the info for making proteins (has codons)
tRNA - brings amino acids to growing polypeptide chain (has anticodons)
rRNA - Main component to structurally make ribosomes
400
There are 3 types of transmembrane proteins discussed in class (Type I, Type II, and multi-pass). What is their general function?
TransMEMBRANE proteins are proteins that are meant to be a part of the membrane. Many function as receptors or channels.
500
Name these structures. Macromolecule family? 3 letter and 1 letter abbreviation? Properties?
Proteins
Glycine - Gly, G, hydrophobic
Asparagine - Asn, N, hydrophilic
500
Why can't cell division and gene expression happen at the same time?
They serve different functions/purposes with different proteins that come into play to access the DNA differently. Both need access to the DNA as a template and if they are trying to work on the same region, it is a means of implication.
500
How is RNA Polymerase II recruited? Where is it recruited?
Transcription Factor Proteins (TF's) piling up and binding to DNA at promoter region which make the right shape for RNA Pol II to bind and start transcribing
500
Name the 3 steps of translation and what they do. What kind of proteins bring tRNA's to the ribosome?
BONUS: What is the ribosomes function? Name the sites and what occurs at each.
1. Initiation - 40S subunit of ribosome and tRNA with Methionine (start) binds to codon on mRNA in P site then 60S subunit is recruited and the ribosome is complete
2. Elongation - Elongation proteins bring tRNA's to the ribosome to add amino acids to the growing polypeptide chain
3. Termination - Stop Codon in mRNA recruits release factor proteins that stops translation, causes the ribosome to fall apart and releases the polypeptide chain
Ribosome is the site for protein synthesis - translates RNA into proteins
A-Site (aminoacyl) - Where correct tRNA carrying amino acid is brought in
P-Site (peptidyl) - Where growing polypeptide chain is
E-Site (exit) - Where used tRNA exits
500
What's the difference between cotranslational import and postranslational import?
Cotranslational Import:
-Proteins finish being translated directly into the Endoplasmic Reticulum (ER)
-In ER proteins are folded, modified, and packed in vesicles to be sent to different parts of the cell
-Membrane-bound proteins are readied by ER
Postranslational Import:
-Proteins finish being translated in cytosol (not RER)
-Import into nucleus and other organelles