Week 2: Genes and pharmacology Flashcards
What does a neuron consist of?
Soma, dendrites and axon
What is the soma, what is it involved in and what are the structures inside it called?
- Central part of the neuron/cell body of the neuron
- Involved in the production of neurotransmitters
- Structures inside are called organelles
What is the fluid inside the cell called?
Cytosol
What is the difference between cytoplasm and cytosol?
Cytoplasm is the substance between a cell’s membrane (its outside layer) and its nucleus (its core).
Cytosol is the fluid part of cytoplasm.
Cytoplasm also consists of organelles and other parts, which float in the cytosol.
Which organelles is not part of the cytoplasm? (i.e. everything within the cell membrane)
Nucleus (the membrane-enclosed organelle within a cell that contains the chromosomes)
What does the nucleus contain?
DNA
What specific parts of DNA assembles the cell?
Genes
What does gene expression mean?
‘Reading’ a cell (the process by which the information encoded in a gene is turned into a function)
What is the final product of gene expression?
The synthesis of molecules (protein)
Where does protein synthesis take place?
Cytoplasm
What carries the genetic message to the sites of the protein syntesis?
mRNA
What is transcription?
The process of assembling a piece of mRNA that contains the information of the gene
What do we call the region where the RNA synthesizing enzyme, RNA polymerase, binds to?
The promoter
What do we call the stop sequence that the RNA polymerase recognizes as the end point of the transcription?
The terminator
What are the parts of DNA called that can not be used to code a protein?
Introns and exons
The process of assembling proteins from amino acids under direction of mRNA is called?
Translation
What do we call the entire lenght of DNA that comprises the genetic information in our chromosomes?
Genome
What does gene copy number variations mean?
Having duplicated genes (molecular phenomenon in which sequences of the genome are repeated, and the number of repeats varies between individuals of the same species)
Many of our genes have small mutations, how do we call that?
Single nucleotide polymorphisms
What is the process called in which drugs are absorbed, distributed, metabolized and excreted in the body?
Pharmocokinetics
What kind of injection is an intraperitoneal injection?
Drug gets injected into the space around the abdominal organs
A drugs margin of safety is determined by the … effect and the … effect, and the measure is called …
Analgesic/pain killing (relieve pain), depressant (reduce arousal and stimulation), therapeutic index (a ratio that compares the blood concentration at which a drug becomes toxic and the concentration at which the drug is effective)
The most optimal drug has (high/low) affinity for sites of action that produce therapeutic effects and will produce effects at a (high/low) concentration and a (high/low) affinity for sites that produce toxic side effects
High, low, low
What is a drug called when it blocks or inibits the postsynaptic effects (blocks the activation of certain receptors on cells, preventing a biological response)?
Antagonist
What is a drug called when it facillitates the postsynaptic effects?
Agonists
What is a drug called when it prevents the neurotransmitter from opening the ion channel?
Receptor blocker or direct antagonists
What does a indirect antagonist and indirect agonist do?
Antagonist: attaches to one of the alternative sites and prevents the ion channel from opening
Agonist: attaches to an alternative site and facillitates the opening of the ion channel
With which two neurotransmitters in the brain are the most synaptic communication accomplished?
Glutamate and GABA
With which neurotransmitter are all muscular movements accomplished?
Acetylcholine (Ach)
Which two types of Acetylcholine (Ach) receptors are there?
Ionotropic: nicotine receptors (convert extracellular chemical signals (neurotransmitters) into electrical information)
Metabotropic: muscarinic receptors (participate in the modulation of synaptic transmission and neuronal excitability throughout the central nervous system)
Which neurotransmitters belong to the subclass catecholamines (increase heart rate, blood pressure, breathing rate, muscle strength, and mental alertness)?
Dopamine, norepinephrine and epinephrine
In what functions is dopamine implicated (3)?
- Movement
- Attention
- Learning
How does the synthesis of dopamine go?
An enzyme turns the procursor, tyrosine, into L-DOPA and another enzyme turns this into dopamine
Name three major dopamine pathways
- Nigrostriatal system
- Mesolimbic system
- Mesocortical system
What are the behavioural effects of the nigrostriatal system, mesolimbic system and mesocortical system (4)?
- Cortical movement
- Reinforcement effect of drugs
- Short term memories/planning
- Cognition, reward, and addiction
What substance are people with Parkinson given and why not just dopamine?
L-DOPA, because dopamine can’t cross the blood brain barrier
Where are the cell bodies of norepinephrine located (3)?
- Pons
- Medulla
- One region of the thalamus
Where does serotonin play a role in (5)?
- Regulation of mood
- In control of sleep
- Eating
- Arousal
- Pain
What is the precursor of serotonin?
Tryptophan
Where does histamine play a role in (2)?
- Wakefullness
- Control of the digestive system and immune system
Which are the four major glutamine receptors?
- NMDA
- AMPA
- Kainate
- Metabotropic glutamate
Is GABA an excitatory or an inhibitory neurotransmitter?
Inhibitory (it functions to reduce neuronal excitability by inhibiting nerve transmission)
Is glumate an excitatory or an inhibitory neurotransmitter?
Excitatory (it increases the likelihood that the targeted postsynaptic neuron will fire an action potential, which will lead to more firing and communication throughout the nervous system)
The removal of which inhibitory neurotransmitter causes the effect of muscles to contract continously?
Glycine (the major inhibitory neurotransmitter in the brainstem and spinal cord, where it participates in a variety of motor and sensory functions)
There is no mechanism for reuptake and recycling of …, they are destroyed by enzymes
Peptides (neuropeptide can modulate (increase or decrease) a postsynaptic response to a neurotransmitter)
Substance derived from what can serve to transmit messages between cells?
Lipids (involved in developmental, maintenance and many other cellular processes of the brain)
Which theory suggests that variation in a trait is caused by many genes, each of which contribute to the phenotype?
Polygenic inheritance (for example hair color, height or skin color)
What refers to the structure and organisation of cognition?
Phenotypic architecture
Which phenomena is the process by which an individual’s genotype influences the environment that they inhabit?
Gene-environment correlation (for example: students with greater intellectual abilities may select classes that are more challenging, which further increases their knowledge)
Name three types of gene-environment correlations
- Active (preference for environment will be a reflection of genetic makeup)
- Evocative/reactive (the association between an individual’s genetically influenced behavior and others’ reactions to that behavior)
- Passive (a person’s environment as a child is influenced by the genetic makeup of the parents which influences their choices in life)
What is a genotype?
The genetic makeup of an organism; in other words, it describes an organism’s complete set of genes
The genotype is a set of genes in DNA responsible for unique traits or characteristics
What is a phenotype?
Observable characteristics or traits
Phenotype is the physical appearance or characteristic of an organism
What is an allele?
Different versions of a gene
Can Y-linked traits be dominant or recessive inherited?
No, Y-linked traits never occur in females, and occur in all male descendants of an affected male. The concepts of dominant and recessive do not apply to Y-linked traits, as only one allele (on the Y) is ever present in any one (male) individual
What does X-linked dominant inheritance mean?
X-linked dominant inheritance occurs when a gene responsible for a trait or disorder is located on the X chromosome. The gene acts in a dominant manner. This means that both males and females can display the trait or disorder when they have only one copy of the gene inherited from a parent
What does X-linked recessive inheritance mean?
X-linked recessive inheritance means that a gene responsible for a trait or disorder is located on the X chromosome
When a son receives the affected X-chromosome from his mother, he is affected (sons cannnot become carriers).
When a daughter receives the affected X-chromosome from her mother, she will become a carrier. Only when a daughter inherits an affected X-chromosome from both father and mother she will become affected
Daughters from an affected father automatically become carrier (or affected when they receive an affected X-chromosome from their mother)
X-linked recessive disorder often have affected males, less affected females
Explain homozygous and heterozygous
Homozygous describes a genotype consisting of two identical alleles at a given locus (eye colour: two blue alleles)
Heterozygous describes a genotype consisting of two different alleles at a locus (eye colour: one blue allele and one brown allele)
Is duchene muscular dystrophy a dominant or recessive X linked disorder?
Recessive X linked disorder (sons have a higher chance for this disorder, when they receive a X from their mother with the disease, they will be affected. Daughters can become carriers without being affected, sons don’t become carriers/only affected)
What are knock-out mice and knock-in mice?
Knock-out mice: gene is removed
Knock-in mice: original gene is replaced
What is the candidate gene approach?
Conducting genetic association studies focused on associations between genetic variation within pre-specified genes of interest, and phenotypes or disease states
What is the genome wide association study?
Examines alle genes comparing two groups (helps scientists identify genes associated with a particular disease or another trait)
Which gene converts dopamine into norepinephrine?
DBH gene (associated with ADHD)
What is the precursor of L-DOPA and into what does L-DOPA convert?
Tyrosine and dopamine
What is the difference between catecholamines and indolamines?
Catecholamines derive from phenylalanine and include dopamine, norepinephrine, and epinephrine -> increase heart rate, blood pressure, breathing rate, muscle strength, and mental alertness
Indolamines are synthesized from tryptophan and include serotonin -> inhibits metabolism
To which category do dopamine, noradrenaline (norepinephrine), and adrenaline (epinephrine) belong?
Catecholamines (neurotransmitters in the central and peripheral nervous systems as well as hormones in the endocrine system)
To which category does serotonin belong?
Indolamines
