PHAR 737 Midterm 1 Flashcards

1
Q

Describe the ENCODE project

A

ENCyclopedia Of DNA Elements

International collaboration of research groups funded by the National Human Genome Research Institute.

Goal is to build a list of functional elements in human genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many base pairs, genes and chromosomes comprise the human genome.

A

3x10^9 base pairs
20,000 genes
23 chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define Genome

A

All the genetic material (DNA) of an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define Genetics

A

Study of single genes and its effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define Genomics

A

Study of all genes in the genome, including their interactions with environmental factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define Pharmacogenetics?

A

The study of genetic influences on an individual’s response to drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define Pharmacogenomics

A

The study of all genes collectively that influence drug responses, and how genome-wide analysis may be used to identify such genes in the search for novel drug targets or as key determinants for drug reactions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Of the 3 billion base pairs in the human genome, how many are variable, how many capture the full human variation, and how many are pharmaceutically relevant?

A

3 million base pairs are variable

100,000 capture the full human variation.

Less than 10,000 may be relevant to pharmaceutical development.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are drugs approved?

A

By trial and error

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do pharmaceutical companies need to specify when it comes to drug action?

A

A specific population, or else the drug will be abandoned (most likely)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How much does it cost to develop a new drug? How long will it take to launch the drug from patent and when will the patent expire?

A

Drugs development usually ranges in price from 500 million to 700 million dollars.

Patent to launch is usually around 12 years, and will last 7.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define efficacy

A

Patients cured at a given dose .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define therapeutic Index

A

Dose range at which drug shows highest efficacy and low toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How prevalent is genetics when looking at US death rates?

A

9 of 10 deaths in the US have a genetic component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What factors influence drug response?

A
Gender
Age 
Body mass
Diet 
Presence of other drugs 
Disease 
Exposure to certain chemicals or toxins (alcohol, tobacco)
Genetic factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Most diseases are caused by this type of interaction

A

gene-environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What main interventions are used for groups that are at high risk of gene-environment interactions caused disease(s)?

A

Diet
Physical activity
Smoking cessation
Alcohol avoidance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is an SNP?

A

Single Nucleotide Polymorphism (or substitution) of one base for another every 1000 nucleotides. SNPs are evolutionarily stable (not changing much between generations)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the significance of Mendelian Inherited Diseases?

A

1200 genes that are currently identified as causing human diseases/traits exhibit inherited phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a Transcriptome?

A

The full range of RNA molecules expressed by an organism or present in a cell at a given time.

Changes in transcriptional activity contributes to a disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a Proteome?

A

The entire set of proteins expressed by a genome, organism, cell or tissue at a certain time.

Constantly changing since proteins are continually being synthesized, modified and degraded. Also species and cell-state dependent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the Epigenome?

A

The epigenome is a series of chemical compounds that can tell the genome what to do.

Epigenomics is the study of changes in the regulation of gene activity and expression that ARE NOT dependent on gene sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the purpose of Systems Biology?

A

To connect the molecular characteristics of a disease with pharmacogenomics to deliver a personalized therapy option to a patient.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the importance of Simple Viral and Bacterial Genomes?

A

This is an untapped resource of raw genomic material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the importance of Ancestral Genomics?

A

Can be used to track the evolution of genomes, duplication events and similarities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the importance of the interpretation of shared characteristics?

A

Determining traits that mammals have gained and lost through evolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the five stages that drugs undergo in the body?

A
Absorption 
Distribution
Target Interaction 
Metabolic Processing 
Excretion from the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How prevalent are genetic factors when it comes to variation in drug response between individuals?

A

20-95 percent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What genes are important for pharmacokinetic properties of drugs? Pharmacodynamics?

A

Those for drug metbolizing enzymes and drug transporters.

Those for enzymes, receptors, and ion channels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How common are SNPs?

A

Occur in at least 1 percent of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Define Haplotype

A

A group of alleles that are rarely separated by recombination (generally inherited together)

Human haplotypes are 60,000 base pairs in size and contain 60 SNPs that travel as a group

Haplotypes are better predictors of drug responsiveness than single, isolated SNPs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe a “Missence” SNP

A

Characterized by changes of amino acids, with about half of such changes occurring in coding sequences.

Can result in the alteration of protein function and is the cause of most monogenetic disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe “Nonsense” SNPs

A

Introduce a stop codon with the same consequences as Missence SNPs (alteration in protein function, cause of monogenetic disease)

34
Q

How many SNPs does the human genome have? Which are most prevalent, where do they occur, and how do they effect us?

A

3 million, distributed randomly

Occur in both coding and non-coding regions, with 2 out of every 3 involving the replacement of cytosine (C) with thymine (T). Some have no effect on cell function but may predispose people to a disease or impact how they respond to certain drugs.

35
Q

What is TSC and what do they do?

A

The SNP Consortium (HapMap Project)

A partnership of scientists from Canada, China, Japan, Nigeria, UK and US that seeks to determine the frequency of certain SNPs in three major world populations.

Goal is to make a public resource that researchers can use to find genes associated with disease and pharmaceutical response in humans.

36
Q

How is pharmacogenetic testing prior to drug therapy limited?

A

Largely to specialized drugs such as chemotherapy agents

37
Q

Explain GWAS

A

Genome Wide Associated Study is a study of many common genetic variants in individuals to determine if any variant is associated with a trait.

38
Q

What are nucleotide subunits composed of?

A

Sugar-phosphate molecule with a nitrogen containing side group, or base, attached to it

39
Q

What are the activated precursors in RNA synthesis?

A

Ribonucleotide triphosphates

40
Q

What direction does the chain grow in RNA synthesis?

A

5’ to 3’

41
Q

What are the stop and start sites in transcription?

A
Start = AUG
Stop = TAA
42
Q

List 4 important transcriptional co-regulators

A
  1. Mediator complexes
  2. Histone chaperone complexes
  3. Histone modifying enzyme complexes
  4. ATP-dependent chromatin remodeling complexes
43
Q

Explain eu- and hetero-chromatin

A

Euchromatin is uncondensed and is considered “good” chromatin (ideal for replication) while heterochromatin is condensed and not favorable for replication (repressing or silencing)

44
Q

Describe how transcription is modulated

A

DNA bound activator protein upstream from enhancer sequence attracts proteins to promoter region that activate RNA polymerase. The DNA can loop around its self to facilitate the interaction of proteins that activate RNA polymerase.

Active repressors can bind to operator sequences near the promoter and interfere with RNA polymermase binding to the promoter.

45
Q

Describe the general process of Translation

A

Amino acids are transported to the ribosome by tRNA (20 different tRNA molecules total, one for each amino acid), tRNA anti-codons find their RNA complement and peptide bonds form between amino acids to form a peptide, with translation stopping once the stop codon has been reached.

46
Q

What is Chromatin?

A

A nucleoprotein complex that causes condensation and organization of DNA. Strings of nucleosomes compose the primary structural unit while nucleosome interactions provide a secondary level of compaction.

47
Q

Describe a histone octamer

A

The 8 protein coplex found at the center of a nucleosome, consisting of 2 copies of each core protein (H2A, H2B, H3, and H4)

48
Q

What is epigenomics?

A

The study of the complete set of epigentic modifications on the genetic material of a cell

49
Q

Describe CRMs and their impact on cells

A

Cis Regulatory modules are short sequences that regulate expression of nearby genes (on the same DNA strand) when transcriptional regulators bind to them.

As a results, only half of the 25,000 protein-coding genes of the mammalian genome are expressed in any given cell.

50
Q

Describe Epigenetics.

A

Heritable traits that aren’t linked to changes in the DNA sequence (changes caused by external or environmental factors)

51
Q

Describe DNA methylation of the human genome

A

Methyl groups added to DNA at CpG sites, with the pattern being determined during embryogenesis (and getting passed over to differentiating cells).

In humans, 3-5% of DNA cytosine is methylated, and this methylation occurs almost exclusively at cytosines that are followed by a Guanine-CpG dinucleotide (5’CpG3’). The process is performed by DNA methyltransferase, and is heritable, reversible, and often used as a therapeutic target. Methylation on the human genome is not uniform.

CpG is methylated in non-promoter regions and un-methylated in promoter region (methylation in promoter region correlates with silencing)

52
Q

In histone modification, acetylation and deacetylation are regulated by…

A

Histone acetyltransferases (HATs) and Histone Deacetylases (HDACs)

53
Q

How do HATs work?

A

HATs catalyze the transfer of the acetyl moiety from acetyl-CoA to the amino group of histone lysine residues, resulting in acetylated lysine and CoA.

Positively charged histones are neutralized and their interaction with the negatively charged DNA is decreased.
In general, this increases gene expression.

54
Q

What can acetlyation regulate in DNA?

A

DNA replication, histone deposition and DNA repair

55
Q

What is the result of lysine acetylation?

A

More opened euchromatin state which is more accessible to transcription factors

56
Q

What are two primary disease examples in humans resulting from histone modifications? Describe each disease.

A

Coffin-Lowry Syndrome:
>Genetic disorder characterized by mental retardation and head/facial abnormalities
>X-linked dominant genetic trait
>results from mutations in the RSK2 gene (histone phosphorylation)

Rubinstein-Taybi Syndrome:
>Short stature, intellectual disability, distinctive facial features, and broad thumbs and first toes
>results from mutations in CREB-binding protein (histone acetylation)

57
Q

What are the three main methods we use for DNA sequencing

A

Chain Termination, aka di-deoxy method (aka Sanger sequencing)

Shotgun Sequencing (fragments DNA into manageable chunks)

Pyrosequencing (fast and accurate)

58
Q

Explain RT-PCR

A

Reverse Transcriptase-Polymerase Chain Reaction is used to determine whether a particular type of mRNA is present.

The process starts with mRNA. cDNA is formed in a reverse transcription process

59
Q

Describe RNA-Seq

A

RNA-seq is simple, faster, and more reliable than other methods. Allows for a comprehensive view of the transcriptome (each transcript is sequenced)

60
Q

What is CHIP-seq

A

Chromatin Immunoprecipitation Sequencing

DNA-bound protein is immunoprecipitated using a specific antibiody, followed by purification of that DNA and then synthesis of sequencing of those purified strands. This method is used to indicate DNA-protein interactions.

61
Q

Explain why RNA expression odes not always reflect protein levels

A

Translational control, degradation and turnover

62
Q

What does Functional Proteomics Encompass?

A

Post-translational modifications
Protein-Protein and Protein- Ligand Interactions
Sequence structure-function relationships

63
Q

Describe Metabolomics

A

New field that uses systematic determination of metabolite levels in the metabolome and their changes over time as a consequence of stimuli

64
Q

Define Metabolome

A

The complete set of small-molecule metabolites found within a biological sample

65
Q

Define Metabolites

A

Intermediates and products of metabolism (antibiotics, pigments, carbs, fatty acids, amino acids, etc.)

66
Q

Describe transgenic mice

A

Mice with germ-line transformations that involve the insertion of genes into the reproductive cells of an organism, which permanently alters the individual and all offspring (transgenic)

Used to study the functions of specific genes in development or disease processes

67
Q

Define Allele

A

One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome

68
Q

Describe the structure/levels of DNA

A

DNA is wrapped around protein molecules called histones; the nucleosome is the combination of DNA and histone protein; the nucleosomes form a bead-like chain, called the chromatin; chromatin will form chromosomes when a cell is getting ready to divide

69
Q

What base pairs are present in DNA? RNA?

A

CG AT

CG AU (uracil substituted for thymine in the case of RNA)

70
Q

Define phenotype

A

The set of observable characteristics of an individual resulting from the interaction of the genotype with the environment

71
Q

Describe PCR

A

Polymerase Chain Reaction, causes DNA amplification

Uses heat to denature DNA, separating the strands, followed by addition of primers that allow polymerase to synthesize the strands in question

72
Q

Main applications of Metbolomics

A

Drug assessment, clinical toxicology, nutri-genomics, functional genomics

73
Q

Challenges with Metabolomics

A

Database is still new and lacks content, there is still a need for standardization, efficiency in identification and better interpretation of the data

Integration with other ‘omics’ fields is also a current challenge

74
Q

What methods are used to measure gene expression levels?

A

RT-qPCR
RNA Microarray Chips
RNA-seq

75
Q

Explain RNA Microarray Chips

A

Reverse transcription used to create cDNA strands (1 infected + 1 normal) which are then combined. Infected is labeled fluorescently. cDNA strands are then applied to the CHIP, which is scanned to determine which genes are expressed in the infected and uninfected samples.

76
Q

What are the 3 different stop codons?

A

UGA, UAA, UAG

77
Q

Methylation of K27 results in…

A

Repression

78
Q

Acetylation of K27 results in…

A

Activation

79
Q

Methylation of K4 results in…

A

Activation

80
Q

What are the steps that lead to protein quantification?

A

Sample extraction, protein fractionation, peptide fractionation, mass spectrometry, protein identification, and finally protein quantification.