Lecture 1: Evolution and Genes
Y-chromosomal Adam
Mitochondrial Eve: mitochondria come from mom
All humans are 99.9% identical
Human Genome Project: 20000 genes, 3 billion nucleotides, <2% of DNA codes for proteins
Each cell has 5 cm of DNA, we have 10 trillion cells
Traits becoming more common based on:
- Variation
- Heritability
- Struggle for existence
- Survival and reproductive rates
Genome: the whole of the genetic information of an organism
Chromosome: a long strand of DNA wound around histones
Telomere: region at the end of the chromosome, protects the DNA during cell division
Gene: part of DNA with instructions to make proteins
Allele: 2 alternative forms of a gene at the same place on a chromosome
Homozygous: same alleles
Heterozygous: different alleles, code for opposite thing
Calico cats: 2 X chromosomes, each for different color - females with stripes
Transcription - nucleus: a piece of DNA is copied into mRNA
- RNA has U instead of T, is shorter and can leave the nucleus
Splicing: introns exit the nucleus, exons are glued together
Translation - cytoplasm: mRNA is then translated into a protein at the ribosome
- Each mRNA codon merges with tRNA (transfer) anticodon
- Each mRNA codon sticks to tRNA anticodon: each tRNA molecule has an amino acid on
one end and an anticodon on the other
- Codon combinations meet at the ribosome, determining the order of amino acids in the
growing protein
Each new amino acid combines with the previous one and forms a chain - the protein
Large proteins can be cut into smaller ones, creating multiple proteins from one gene
1
,Proteins:
- Building blocks
- Receptors in cell membrane - receive communication
- Part of cell structure and function (cytoskeleton)
- Transport oxygen - hemoglobin
- Form ribosomes to create new proteins
- Immune system
- Hormones and neurotransmitters - communicators
- Fuel and heat production
- Enzymes - molecular glue / scissors
Serotonin is not a protein from your DNA, but the enzymes which make it are
DNA control of transcription can produce more or less serotonin
- DNA via enzymes controls serotonin production
Mutations:
- SNP: single nucleotide polymorphism
- Crossover
- Tandem repeat / satellite DNA: repeated duplications of a DNA sequence, short
repeated base-pair sequences
- Lengths vary
- Can affect transcription of certain genes
- Insertions and deletions: addition or loss of one or more nucleotides or sections of
chromosomes
- Inversion, translocation and duplication: change in part of chromosomes
Epigenetics: the study of heritable phenotype changes that do not involve alterations in DNA, in
response to environment (stress, food, smoking)
2
,Lecture 2: Communication and Endocrine System
Ionotropic receptor: ligand-gated ion channels (direct)
Metabotropic receptor: G-protein-coupled (indirect, 2 steps)
Cytoskeleton: cell form / shape, connection with other cells, within cell transport (elements:
intermediate filaments, microfilaments, microtubules and centrioles)
- Protein filaments function in movement (muscles) and support
Cell-cell connections:
- Desmosomes: flexible, some fluids can enter and exit (skin tissue)
- Tight junctions: very tight, nothing can pass inside, goes through cells (gut lining)
- Gap junctions: contract together, very fast (cardiac cells)
Endoplasmic reticulum: layer of membranes formed into stacks, where new proteins are made
- Rough ER: ribosomes attached to it, protein synthesis
- Smooth ER: no ribosomes, calcium storage, synthesis of fatty acids and steroids
Golgi apparatus: layer of membrane structures, produce vesicles for storage
Mitochondrion: has its own DNA, from mother, ATP production
- Energy is released when a phosphate group is released from ATP
- Energy is stored when ADP + phosphates
Cellular communication:
Electrical: action potentials, synapses
- Neurotransmitter communication at the synapse
- Released when an action potential arrives at presynaptic terminal
- Vesicles with neurotransmitters
- Exocytosis of neurotransmitter release
Neurotransmitters bind to their receptor
The receptor becomes activated and has a cellular response
- Can be opening of ion channel
- Can be intracellular mechanism
3
, Hormones: long distance communicators, mostly outside CNS
3 chemical classes:
1. Monoamines: derived from single amino acids
- Thyroid hormone
- Epinephrine
- Norepinephrine
- Dopamine
Example: catecholamines
Role in acute stress response
Derived from amino acid tyrosine
- Dopamine
- Noradrenaline (=norepinephrine)
- Adrenaline (adrenal medulla)
Proteins from DNA transform tyrosine -> dihydroxyphenylalanine -> dopamine -> norepinephrine
-> epinephrine
Adrenal gland: on top of kidneys
Medulla (inside) secretes amine hormones epinephrine and norepinephrine in response to
sympathetic activation (message from the brain)
Dopamine is secreted by the hypothalamus and the adrenal medulla
Different regions of the adrenal gland produce different things
Medulla (inside): adrenaline and noradrenaline, very fast nerve signal
Cortex (outer): steroid hormones, including cortisol, signal from another hormone, slower
Thyroid hormone pathway:
3 hormones needed to create thyroid + negative feedback
Hypothalamus: releases TRH
Anterior pituitary gland: releases TSH in response
Thyroid gland (in throat): releases thyroid hormones T3 and T4 in response
Needs iodine for production
Thyroid hormone T3 and T4:
4
Y-chromosomal Adam
Mitochondrial Eve: mitochondria come from mom
All humans are 99.9% identical
Human Genome Project: 20000 genes, 3 billion nucleotides, <2% of DNA codes for proteins
Each cell has 5 cm of DNA, we have 10 trillion cells
Traits becoming more common based on:
- Variation
- Heritability
- Struggle for existence
- Survival and reproductive rates
Genome: the whole of the genetic information of an organism
Chromosome: a long strand of DNA wound around histones
Telomere: region at the end of the chromosome, protects the DNA during cell division
Gene: part of DNA with instructions to make proteins
Allele: 2 alternative forms of a gene at the same place on a chromosome
Homozygous: same alleles
Heterozygous: different alleles, code for opposite thing
Calico cats: 2 X chromosomes, each for different color - females with stripes
Transcription - nucleus: a piece of DNA is copied into mRNA
- RNA has U instead of T, is shorter and can leave the nucleus
Splicing: introns exit the nucleus, exons are glued together
Translation - cytoplasm: mRNA is then translated into a protein at the ribosome
- Each mRNA codon merges with tRNA (transfer) anticodon
- Each mRNA codon sticks to tRNA anticodon: each tRNA molecule has an amino acid on
one end and an anticodon on the other
- Codon combinations meet at the ribosome, determining the order of amino acids in the
growing protein
Each new amino acid combines with the previous one and forms a chain - the protein
Large proteins can be cut into smaller ones, creating multiple proteins from one gene
1
,Proteins:
- Building blocks
- Receptors in cell membrane - receive communication
- Part of cell structure and function (cytoskeleton)
- Transport oxygen - hemoglobin
- Form ribosomes to create new proteins
- Immune system
- Hormones and neurotransmitters - communicators
- Fuel and heat production
- Enzymes - molecular glue / scissors
Serotonin is not a protein from your DNA, but the enzymes which make it are
DNA control of transcription can produce more or less serotonin
- DNA via enzymes controls serotonin production
Mutations:
- SNP: single nucleotide polymorphism
- Crossover
- Tandem repeat / satellite DNA: repeated duplications of a DNA sequence, short
repeated base-pair sequences
- Lengths vary
- Can affect transcription of certain genes
- Insertions and deletions: addition or loss of one or more nucleotides or sections of
chromosomes
- Inversion, translocation and duplication: change in part of chromosomes
Epigenetics: the study of heritable phenotype changes that do not involve alterations in DNA, in
response to environment (stress, food, smoking)
2
,Lecture 2: Communication and Endocrine System
Ionotropic receptor: ligand-gated ion channels (direct)
Metabotropic receptor: G-protein-coupled (indirect, 2 steps)
Cytoskeleton: cell form / shape, connection with other cells, within cell transport (elements:
intermediate filaments, microfilaments, microtubules and centrioles)
- Protein filaments function in movement (muscles) and support
Cell-cell connections:
- Desmosomes: flexible, some fluids can enter and exit (skin tissue)
- Tight junctions: very tight, nothing can pass inside, goes through cells (gut lining)
- Gap junctions: contract together, very fast (cardiac cells)
Endoplasmic reticulum: layer of membranes formed into stacks, where new proteins are made
- Rough ER: ribosomes attached to it, protein synthesis
- Smooth ER: no ribosomes, calcium storage, synthesis of fatty acids and steroids
Golgi apparatus: layer of membrane structures, produce vesicles for storage
Mitochondrion: has its own DNA, from mother, ATP production
- Energy is released when a phosphate group is released from ATP
- Energy is stored when ADP + phosphates
Cellular communication:
Electrical: action potentials, synapses
- Neurotransmitter communication at the synapse
- Released when an action potential arrives at presynaptic terminal
- Vesicles with neurotransmitters
- Exocytosis of neurotransmitter release
Neurotransmitters bind to their receptor
The receptor becomes activated and has a cellular response
- Can be opening of ion channel
- Can be intracellular mechanism
3
, Hormones: long distance communicators, mostly outside CNS
3 chemical classes:
1. Monoamines: derived from single amino acids
- Thyroid hormone
- Epinephrine
- Norepinephrine
- Dopamine
Example: catecholamines
Role in acute stress response
Derived from amino acid tyrosine
- Dopamine
- Noradrenaline (=norepinephrine)
- Adrenaline (adrenal medulla)
Proteins from DNA transform tyrosine -> dihydroxyphenylalanine -> dopamine -> norepinephrine
-> epinephrine
Adrenal gland: on top of kidneys
Medulla (inside) secretes amine hormones epinephrine and norepinephrine in response to
sympathetic activation (message from the brain)
Dopamine is secreted by the hypothalamus and the adrenal medulla
Different regions of the adrenal gland produce different things
Medulla (inside): adrenaline and noradrenaline, very fast nerve signal
Cortex (outer): steroid hormones, including cortisol, signal from another hormone, slower
Thyroid hormone pathway:
3 hormones needed to create thyroid + negative feedback
Hypothalamus: releases TRH
Anterior pituitary gland: releases TSH in response
Thyroid gland (in throat): releases thyroid hormones T3 and T4 in response
Needs iodine for production
Thyroid hormone T3 and T4:
4
