Old Exam Practice Questions Flashcards
1
Q
Draw Hydrogen bond of adenine and thymine without sugar phosphate backbone.
A
2
Q
At which two spots can ATP and glycolysis be generated? (weird wording, probably a translation error)
A
ATP can be generated in:
1) the cytoplasm by glycolysis
2) the mitochondrion by the citric acid cycle and oxidative phosphorylation
3
Q
What is a palindrome? Draw a sequence of 6 bases as a double strand.
A
A palindrom is a sequence of DNA where the bases at the beginning of the sequence are complementary to those in the other half of the sequence.
Example:
CCGCGG
GGCGCC
4
Q
Name 3 second messengers by their full names:
A
1) cyclic AMP (cAMP)
2) cyclic GMP (cGMP)
3) Calcium Ion (Ca2+)
4) inositol 1,4,5-trisphosphate (IP3)
5) Diacylglycerol (DAG)
5
Q
How many genetic codes exist and how many of them are stop codons? How many are start codons?
A
3 base codons, 4 bases total = 4^3 codons = 64 codons
3 stop codons
1 start codon
6
Q
Describe the wobble position
A
The base on the anticodon of tRNA that corresponds to the 3’ codon on the mRNA can sometimes be a flexible I (inosine) base that can match with more than one base.
7
Q
Name 4 RNAs and their functions
A
1) mRNA - is translated by the ribosome to make protein
2) rRNA - makes up the structure of the ribosome and catalyzes some reactions having to do with translation
3) tRNA - transfer RNA that brings the amino acids to the ribosome to be assembled into polypeptides.
4) snRNA - small nuclear RNA. Makes up the spliceosome
8
Q
Draw and label a lineweaver burk diagram
A
9
Q
Name 3 Epitope tags that can be used in affinity chromatography.
A
- His tag - a string of histidine residues
- MBP
- GlutathionS
10
Q
Name 3 small molecule electron carriers as they can be found in oxidative phosphorylation.
A
1) NADH
2) FADH2
3) QH2
11
Q
Why does SDS-PAGE contain SDS and Beta-mercaptoethanol?
A
Contains SDS (sodium dodecyl sulfate) to disrupt all non-covalent interactions
Contains beta-mercaptoethanol to reduce disulfide bonds
12
Q
What are northern, western, southern blot and what molecules can be identified with it?
A
Electrophoresis and then transfer to a membrane and stained or tagged to see where specific molecules are and how far they have travelled - which corresponds to size.
1) Southern - DNA
2) Northern - RNA
3) Western - Protein
13
Q
What is an Operon and ORF and what are the differences?
A
1) an operon is a sequence on DNA that is transcribed depending on if certain conditions are met. It will have a promotor site, a operator site, and then structural genes which code for the mRNA to be translated. They are mostly associated with prokaryotes, but they will sometimes show up in eukaryotes. They can be turned on or off, meaning allow transcription of the structural genes up on the release or binding of a represor to the oporator site.
2) ORF, or open reading frame, is a stretch of bases starting at a start codon and ending at a stop codon that has the potential to be translated.
3) the difference between an operon and an ORF is that the operon can be within an ORF potentially, but is regulated by repressor proteins to stop or allow transcription. An ORF is just a potentially translatable region due to the presence of bases between a start and stop codon.
14
Q
What is a ribozyme? Name 2 examples.
A
A ribozyme is RNA that demonstrated catalytic acitivity.
1) the rRNA in the ribosome
2) the snRNA in the spliceosome
15
Q
Name 3 organic coenzymes and the most important cosubstrates
A
1) Coenzyme A
2) Coenzyme Q
3) SAM
Cosubstrates:
ATP
GTP
NAD+
H2O
16
Q
What are okizaki fragments?
A
The lagging strand during DNA replication still has to be assembled by adding to the 3’ end, but cannot simply start from the 3’ end of the template strand since it has not been unzipped by helicase yet.
It is assembled in small pieces called Okizaki fragments , with an RNA primer being placed in a point on the template strand that has been opened up.
Small pieces of DNA (the okizaki fragments) are created by DNA polymerase and ligated together by DNA ligase. This is how the lagging strand is assmebled.
17
Q
Name and describe 3 methods to detect protein-protein interaction.
A
- Co-immunoprecipitation
- yeast 2 hybrid assay
- tandem affinity chromatography
18
Q
Which 3 amino acids can become phosphates?
A
1) Tyrosine
2) Serine
3) Threonine
basically the 3 with hydroxyl groups.
19
Q
Which 2 alpha-keto acids from the citric acid cycle can be transformed into which amino acids?
A
1) Oxaloacetate - can be used as a precurser for:
- Aspartate, which is used as a precurser for:
- Asparagine, Methionine, Threonine, Lysine, Isoleucine
2) Alpha-ketoglutarate - Can be used as a precurser for:
- Glutamate, which is used as a precurser for:
- Glutamine, Proline, Arginine
20
Q
Describe cooperative binding and allostery
A
1) Cooperative binding - as one substrate binds to the enzyme, more active sites open up allowing more substrates to bind.
2) Allostery - the binding of a molecule to a site other than the active site regulates the enzyme, either enhancing or limiting its activity.
Allosterically regulated enzymes will exhibit non-Michaelis Menton kinetics.
21
Q
Describe the structure of 5-methyl-cytosine. Where can it be found in a mammal?
A
Is basically a standard Cytosine base, but it has a methyl group at the 5’ carbon (where it would be found in Thymine).
It is found that the CpG junctions in mammals.
22
Q
Describe and draw the structure of ATP
A
Adenosine Triphosphate.
Is 3 phosphoryl groups attached to a ribose sugar attached to an adenine.
23
Q
Process steps of pre-mRNA in Eukaryotes.
A
1) capping the 5’ end
2) addition of the polya(A) tail to the 3’ end
3) splicing out introns and connecting exons
24
Q
Main differences between prokaryotes and eukaryotes in cell division.
A
- Eukaryotes: Mitosis and cytokinesis
- Prokaryotes: Binary fission
25
Name 3 prokaryotic proteins that are important for homologous recombination. Describe also their function.
1. RecA
1. Promotes strand invasion
2. Cre-Recombinase
1. Works through Holliday junction intermediates
3. Helicase
4. RuvA
26
How do you divide proteins according to size, charge, weight?
1) Size - gel filtration chromatography (or molecular exclusion chromatography)
2) Charge - ion exchange chromatography
3) Weight - SDS-PAGE (electrophoresis)
27
Name 2 methods for identifying protein 3D structure.
1) X-ray crystallography
2) NMR spectroscopy
28
What do U1 and U2 snRNA do at splicing?
U1 recognizes 5’ splice site by base- pairing with 5’ region of intron; U2 recognizes branch point and loops out adenosine for nucleophilic attack of 5’ splice site
29
Describe the RNA hydrolysis mechanism. Why is RNA more sensitive than DNA?
The OH group that is present at the 2' carbon on the ribose sugar in RNA (not present in DNA) does a nucleophilic attack on the phosphate group in the backbone, breaking it. The fact that DNA does not have this hydroxyl group is why it is more stable than RNA.
30
What is apoptosis? What do caspases do?
Apoptosis is programmed cell death.
Caspases are protease enzymes that play key roles in apoptosis, including initiation, execution and inflamation.
(I should probably get a better answer for this one)
31
What is the restriction point?
Point in the cell cycle after which the cell cycle will go ahead without external stimulus. Is in later G1 phase.
32
What is the karyotype, autosome, genome?
1) Karyotype - number and appearance of chromsomes in a eukaryotic cell nucleus.
2) Autosome - chromosome that is not a sex chromosome
3) Genome - the complete genetic information in a cell or organism. Including DNA and RNA.
33
Which RNA polymerase for which RNA?
1) RNA polymerase I - 18S, 5.8S, 28S rRNA
2) RNA polymerase II - mRNA precursors and snRNA
3) RNA polymerase III - tRNA and 5S rRNA
34
Molecular machine for ATP-synthesis, mRNA processing and protein synthesis
1) ATP Synthesis - ATP synthase
2) mRNA processing - spliceosome
3) Protein synthesis - ribosome
35
What is a methyl donar and what are its pre-stages?
S-adenosylmethionine is formed from the transfer of an adenosyl group from ATP to the sulfur atom of methionine.
36
What are the different types of reversible enzyme inhibitors and what do they do?
(A) Enzyme–substrate complex;
(B) a competitive inhibitor binds at the active site and thus prevents the substrate from binding;
(C) an uncompetitive inhibitor binds only to the enzyme–substrate complex;
(D) a noncompetitive inhibitor does not prevent the substrate from binding.
37
What are the effects of the different inhibitors types on Michaelis-Menton diagrams?
Competative: As the concentration of a competitive inhibitor increases, higher concentrations of substrate are required to attain a particular reaction velocity.
Uncompetative: The reaction pathway shows that the inhibitor binds only to the enzyme–substrate complex. Consequently, Vmax cannot be attained, even at high substrate concentrations. The apparent value for KM is lowered, becoming smaller as more inhibitor is added.
Noncompetative: The reaction pathway shows that the inhibitor binds both to free enzyme and to an enzyme–substrate complex. Consequently, as with uncompetitive competition, Vmax cannot be attained. In pure noncompetitive inhibition, KM remains unchanged, and so the reaction rate increases more slowly at low substrate concentrations than is the case for uncompetitive competition.
38
What are the effects of the different inhibitors types on Lineweaver-Burke diagrams?
Competative: A double-reciprocal plot of enzyme kinetics in the presence and absence of a competitive inhibitor illustrates that the inhibitor has no effect on Vmaxbut increases KM.
Uncompetative: An uncompetitive inhibitor does not affect the slope of the double-reciprocal plot. Vmax and KM are reduced by equivalent amounts.
Noncompetative: A double-reciprocal plot of enzyme kinetics in the presence and absence of a pure noncompetitive inhibitor shows that KM is unaltered and Vmax is decreased.
39
Describe the Key-Lock model
The active site of an enzyme can only fit substrates that specifically fit the exact shape of the active site.
40
Catalytic triad in chymostrypsin and specifications, what bonds does it break?
The Ser-His-Asp catalytic triad in chymotrypsin hydrolyzes the peptide bonds on the carboxyl side of aromatic or large hydrophobic amino acids.
41
UV damage and repair
UV light covalently links adjacent pyrimidine residues.
DNA photolyase uses light energy to break this covalent bond, an example of a direct repair system.
42
DNA replication adn RNA translation, proof reading and repair.
DNA polymerase proof reads as it creates new strands, if there are mismatched bases, they are excised into the exonuclease site of the polymerase.
During RNA translation, the aminoacyl-tRNA synthetases actual do a certain amount of proof reading. If a tRNA is linked to the wrong amino acid, it will be excised by the aminoacyle-tRNA synthetase immedietly.
Fidelity is basically the accuracy of this stuff. How well it is replicated or translated etc. High fidelity is very very important in replication. Less important in translation.
43
Degenerated code: Start and stop genetic codes, how to get from 5' to 3'
The genetic code is degenerate. This means that some amino acids can be encoded by more than one codon.
Start codon is the one that codes for methionine.
3 stop codons
44
What methods of DNA mending and modification?
DNA repair mechanisms:
1) Proofreading
2) Mismatch repair
3) Direct repair (photolyase is an example of this)
4) nonhomologous end joining - repairs breaks on both strands that separate DNA into 2 separate strands.
DNA can be methylated to prevent restriction enzymes from cleaving it.
45
With what method do you unlock bacteria cells in order to isolate plasmid?
1. Lysis method – alkaline lysis
1. Use an alkaline buffer with NaOH and SDS
1. Denatures plasmid and genomic DNA
2. SDS solubilizes cell membrane
3. NaOH helps break down cell wall.
2. Neutralize solution, bringing plasmid DNA back into the solution
3. Small plasmids easily re-anneal, genomic DNA still tangled and denatured.
4. Centrifuge, plasmids will be in solution (supernatant)
Genomic DNA will be in pellet
46
Relate: catalytic enzyme, enzyme prestage, catalytic RNA, cofactor, nucleotide, amino acid.
An zymogen (enzyme before it is activated) needs a cofactor to become a functional enzyme. Catalytic RNA is similar to a catalytic enzyme, except that it is made of RNA nucleotides rather than amino acids. An example of catalytic RNA would be snRNA in the spliceosome.
47
What is apoptosis? What catlysis creates caspases?
1. Apoptosis is programmed cell death
2. Caspases are proteolytic enzymes which break down cell
3. Caspase creation catalyzed by apoptotic-peptidase-activating-factor-1 (APAPF-1)
48
What is catabolism, anabolism, metabolism
Anabolism: The processes in a system that require energy to build larger molecules from smaller ones.
Catabolism: The processes in a system that break down larger structures into smaller ones. Often generate energy.
Metabolism: All the catabolic and anabolic reactions in a system together.
49
NAme 3 protein modifications. In which compartments? What are the donor molecules?
1) Phosphorylation - ATP
2) Acetylation - mitochondria (citric acid cycle) - acetyl CoA
3) Myristoylation - myristoyl CoA
4) ADP ribosylation - NAD+
5) Farnesylation - Farnesyl pyrophosphate
6) gamma-carboxylation
7) sulfation - 3'-phosphoadenosine-5'-phosphosulfate
8) Ubiquination - ubiquitin
50
Name 3 physical/chemical characteristic of proteins and one chromatography method each.
1) Having a lot of Arginine residues, giving it a positive charge - cation exchange chromatography.
2) having a long string of histidine residues at the end of it (His tag) - affinity chromatography
3) The size of the protein - size exclusion chromatography
51
Name the amino acids with sulfur, hydroxyl groups, and aliphatic
Sulfur containing: Cysteine, methionine
Hydroxyl group containing: Tyrosine, Serine, Threonine
Aliphatic: Alanine, glycine, isoleucine, leucine, proline, valine
52
What do the sigma and rho factor do in bacteria?
1) sigma factor: is a part of the RNA polymerase for transcription. Identifies the initiation site for the RNA polymerase and then separates after a few bases have been transcribed.
2) rho factor: terminates transcription. Attaches to the nascent RNA and stops transcription upon reaching the rermination site.
53
In what phase of the cell cycle are the sister chromatids divided? What happens in the telophase?
1. Sister chromatids are divided in anaphase
2. In telophase the chromosomes begin to decondense, the contractile ring begins to form, the nucelear envelope begins to reform.
54
What are centromeres and telomeres?
Centromere: center region of a chromosome that links sister chromatids.
Telomere: long, non-codong regions at the end of a chromosome that protect the coding ends from being degraded. Are created by telomerase.
55
What interactions stabilize the double helix in DNA?
Hydrogen bonds hold double helix together with watson crick base pairs.
Van der waals forces keep adjacent nucleotide bases together, this is known as base stacking.
56
What reactions are being created by enzymes with cobalamines, what dietary (trace) mineral is contributing to that process?
Methylations. Trace mineral is probably cobalt, ingested through vitamin B12
57
What 3 basic enzyme activities are needed for replication?
1. Helicase unzips DNA strand to make replication fork
2. DNA Primase primes DNA for replications
3. DNA Polymerase copies
4. DNA Ligase joins 3’ and 5’ ends together of new strand
58
Name 3 options to regulate enzyme activity.
1) allosteric regulation
2) environmental regulation (pH etc)
3) reverisible inhibitor regulation
59
Describe 3 methods of protein protein interaction
1) non-covalent bonding (hydrogen bonds, van der waals interactions)
2) hydrophobic interactions
3) Covalent
60
Name 3 DNA-binding motifs that can be found in proteins.
1) Basic leucine zipper
2) helix-turn-helix
3) zinc-finger domain
61
2 functions of chromatin in eukaryotic cells
1) keeps DNA compact and organized
2) can be modified to either allow or restrict transcription
62
What are 3 differences between DNA and RNA
1) DNA has a deoxyribose sugar without a hydroxyl group on the 2' carbon
2) DNA is double stranded
3) DNA has thymine nucleotide, RNA has Uracil nucleotide
63
What 3 metabolic pathways are taking place in mitochondria?
1) Beta oxidation of fatty acids
2) citric acid cycles
3) oxidative phosphorylation
64
Name 3 protein modifications that are being used for anchorage in membranes and AS modification.
1) Palmitoyl group
2) a farnesyl group
3) a GPI anchor
4) Prenylation
65
Examples for mono, di, polysaccharide compounds
Monosaccharide: Glucose
Disaccharide: Maltose
Polysaccharide: Glycogen
66
For which protein is Laci code and where is it binding at the Lac Operon
Lac i codes for the Lac repressor. It binds to the O operator site
67
How does chain length and C-C doulbe bonding influence the melting temperature of aliphatic acids?
1) Chain length: Longer chains stack better, so are more stable. They will have a higher melting temperature
2) Double bonds cause kinks in the structure, making the stacking less stable, lowering melting temperature
68
Name 3 motor protein classes, what structures do they attach to?
1) Myosins - bind to actin
2) kinesins - bind to microtubules
3) dyneins - bind to microtubules
4) rotary motor that drives bacterial motion
69
picture of polypeptide chain with names of amino acids: which amino acids can be phosphorylated?
Serine, threonine, or tyrosine residues may be phosphorylated.
70
name 3 different DNA binding transcription factor
1) TATA box binding protein
2) sigma factor
3) heat shock binding factor
4) lac repressor
71
to what 3 reactions is cobalamin contributing. Which dietary minerals are present in cobalamines?
1) intramolecular rearrangements
2) methylations (as in the synthesis of methionine)
3) the reduction of ribonucleotides to deoxyribonucleotides
vitamin B12 (also known as cobalamin) contains a central cobalt atom
72
name 3 co-enzymes and their function
1) Coenzyme A - is acetylated to form acetyl CoA, a key part of various pathways
2) Coenzyme Q - is a key part of the electron transport chain in oxidative phosphorylation
3) NADH: used by electron transport chain
4) FADH2: used by electron transport chain
73
Name the necessary steps of glycolysis to create ATP
1) the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate by phosphoglycerate kinase. Uses 1 ADP to create 1 ATP.
2) The creation of pyruvate from phosphoenolpyruvate by pyruvate kinase. Uses 1 ADP to create 1 ATP
74
Describe 2 reactions that are catalyzed by aminoacyl tRNA synthetase
1) the activation of the amino acid via the creation of aminoacyl-AMP
2) the attachement of the aminoacyle part to tRNA to create aminoacyle-tRNA
75
draw tripept Met-Pro-His and its formylation reaction
look at curve thing to it.
76
3 differences between active transport and diffusion
1) active transport requires an input of energy while diffusion does not
2) diffusion can happen through membranes while active transport requires proteins (such as transporters and channels)
3) active transport can go against the concentration gradient, diffusion must go with it.
77
plasmid vector characteristics
1) circular double stranded DNA
2) self replicating
3) selectable marker genes
4) origin of replication
5) Signal sequences
6) extrachromosomal
78
Describe principles of affinity chromatography, size exclusion chromatography, hydrophobic interaction chromatography
1) Affinity chromatography: marker sequences/tags on target are known. They are targeted by the matrix in the column
2) size exclusion: small porous beads are in the column, smaller proteins fit in pores and do not go through column as quickly.
3) hydrophobic interaction: beads also have nonpolar groups that attract the target protein depending on its hydrophobicity.
79
calculate the isotonic NaCl concentration
this is the NaCl concentration that is the same as the ionic concentration of blood.
80
Explain: transcriptomics, proteomics, genomics
1) transcriptomics: the study of the genes in an organism, or the mRNA that may be transcribed from the DNA
2) proteomics: the study of the protein that may be expressed in an organism. Or the protein which may be synthesized via translation.
3) genomics: the study of the complete genetic material present in an organism
81
Difference between biological membrane and triacylglyceride. Draw phosphatidylserine
1) Membrane lipids: are amphipathic molecules (meaning they contain both a hydrophilic and a hydrophobic moiety.) With 2 hydrophobic fatty acid chains parallel to each other.
2) Triacylglyceride: Highly concentrated energy storage. 3 fatty acid tails and a glycerol.
82
Describe the machanisms of DNA repair and when they occur (as in what damage do they repair)
1) proofreading - non watson crick base pair in the polymerase
2) mismatch repair - also for non-watson crick base pair. uses 2 proteins, 1 for detecting the mismatch and the other for recruiting an endonuclease that cleaves the newly synthesized DNA strand close to the lesion to facilitate repair.
3) direct repair: an example of which is photlyase catalyzed cleavage of a UV induced dimer.
4) base excision repair - excision of a modified base. binding of an enzyme to damaged DNA flips the affected base out of the DNA and into the active site of the enzyme.
5) Nonhomologous end-joining - repairs breaks in double helix strand that are close enough to each other to create 2 separate strands of DNA.
83
Describe cysteine biosynthesis
1) 3-Glyceraldehyde is the precursor to serine
2) serine is the precursor to cysteine (and glycine)
3) homocysteine is created through the activated methyl cycle (using s-adenosyl methionine)
4) Homocysteine + serine \<---\> cysteine + alpha-ketobutyrate + NH4
84
name types of base pairs
1) watson crick
2) reverse watson crick - different connecting atoms
3) Hoogsteen - paarung = seems to be 3 connecting molecules. Not necessarily with nucleic acids.
4) reverse hoogsteen paarung - different connecting atoms
5) wobble position
85
Spliceosome with units and functions
Spliceosome: excises introns and connects exons in pre-mRNA in eukaryotes. Made up of 5 snRNPs (small nuclear ribonucleoproteins). Each serves a different function in the spliceosome.
1) U1: binds the 5' splice site
2) U2: Binds the branch site and forms part of the catalytic center
3) U5: Binds the 5' splice site and then the 3' splice site
4) U4: Masks the catalytic activity of U6
5) U6: Catalyzes splicing
86
Types of splicing
1) Spliceosome catalyzed splicing
2) Self-splicing (group 1 and 2)
87
Describe the function of centromeres, telomeres, origin of replication.
1) Centromeres:
2) Telomeres: non-coding DNA regions at the ends of DNA strands that are created by telomerase after replication. The protect the DNA from degredation after replication.
3) Origin of replication: the start site of replication. In E.Coli, there is one site. in Eukaryotes, there are multiple sites defined by AT rich sequences. It is around these sites that the origin of replication complexes (ORCs) are assembled.
88
Draw an Amino acid
Seriously? you know what to do.
89
How do enzymes accelerate speed?
Enzymes accelerate the reactions by lowering the activation energy of the reaction.
90
Give an example: which protein modification is important for signal transduction?
Phosphorylation/dephosphorylation: example is activation of G-proteins in epinephrine signaling pathway by phosphorylation. Ends with activated protein kinase A.
91
Give an example of post translational modification
1) phosphorylation. For example the activation of a G protein in the epinephrine signaling pathway.
92
what cofactor is the main donor for methyl groups? What are the pre-stages?
Main donor is S-adenosylmethionine (SAM)
prestages are methionine and ATP.
93
Give the definition of semi-conservative, semi-continuous
1) Semi-conservative: refers to the fact that in DNA replication, each new DNA molecule is made of one strand from the parent molecule and one newly synthesized strand.
2) semi continuous: refers to the nature of DNA replication. The leading strand is synthesized continuously, but the lagging strand is synthesized in fragments called okizaki fragments.
94
Give a definition of karyotype, sister chromatids, autosomes
1) Karyotype: the number and type of chromosomes in an organism.
2) sister chromatids: the copies of the chromosome that are created during mitosis.
3) Autosomes: non sexual chromosomes.
95
In what way are metabolic pathway enzymes encoded (+ regulation elements) in bacteria?
1) Phosphorylations
2) acetylaction
3) methylation
4) basically, reversible covalent modification, could also use allosteric regulation.
5) might actually be referring to operons. in which case the answer would be with the standard operon configuration in prokaryotes in which the binding of a repressor to the O site stops the structural genes from being transcribed into mRNA.
96
Describe the spcific import to the core of replication
might be referring to the origin of replication, in which case it is the site at which replication is intitiated.
97
What cytoskeleton elements can be used to separate sister chromatids? what organelle and what metabolite is used?
Need a better answer for this
98
How do you destroy cells, what enzymes and activities are being used?
1) Apoptosis is programmed cell death. Caspases are the proteolytic enzymes used.
99
Give the definition for frameshift mutations, point mutations, loss of genetic variation.
1) frameshift mutations: the reading frame for codons is 3 at a time. Mutations that throw off this reading frame (deletions or insertions of 1 or 2 bases)
2) point mutations: when a single base is inserted, deleted, or mutated.
3) loss of genetic variation: when a population is no longer big enough to sustain itself. Genes that are potentially harmful will become more likely to be expressed in a smaller population since homozygous genes will become more likely to be expressed.
100
Describe induced fit with catalytic characteristics
Induced fit model of enzyme function is where the enzyme will change the shape of its active site to accomidate a substrate.
101
Describe the cell cycle phases. Where is the cell cycle checkpoint and where is Cyclin concentration being regulated?
Need to research this better
102
What adaptor molecule connects genetic code with amino acids and what is the mechanism?
Aminoacyle tRNA synthetase connects amino acids to tRNA corresponding to the 3 base codon on the mRNA. Aminoacyle tRNA synthetase activates the amino acids, creating aminoacyl-AMP. Aminoacyl tRNA synthetase then catalyzes the transfer of the aminoacyl group to the tRNA. The tRNA brings the amino acid to the ribosome, where it is added to the growing amino acid chain.
103
How is cell import and export regulated?
Receptor mediated endocyctosis and exocytosis?
I need to research this better.
104
What amino acids contain sulfur? what amino acid is the most basic one? What amino acid is never in an alpha helix?
1) Cysteine and methionine contain sulfur.
2) Arginine is the most basic
3) Proline is never in alpha helixes because it is cyclized
105
Name 2 functions of the ER
need to research this better
106
Explain histone code and give examples
Chromatin is a protein around which DNA is wrapped. The overall charge of the chromatin determins how tightly the DNA is wrapped. Tightly wrapped DNA is harder to transcribe to mRNA. Histone tails are attached to the chromatin. Modifications of these tails can change the overall charge of the chromatin and thus how tightly the DNA is wrapped around the chromatin.
1) H4 K8 acetylation - activation
2) H3 K14 acetylation - activation
107
Name 4 examples of energy transformation that are supported by enzymes
Need to research this better
108
Draw oxaloacetate. Into what amino acid can it get transaminated?
It can be transaminated into Aspartic Acid/Aspartate
109
How can you change the melting point of a triglyceride?
Shorten the fatty acid chains, change them for different ones, add double bonds.
110
Give the definition of the 5'UTR
The 5'Untranslated region is the part on the 5' end of the mRNA that is not translated since it is before the start codon. In prokaryotes this is where the Shine-Dalgarno sequence is located. It will often form complex secondary structures to facilitate translation.
