Table of Contents
Genetics
Three branches:
- Molecular Genetics - molecules of gene, DNA, RNA, protein
- Mendelian Genetics aka Transmission Genetics - how traits are passed to offspring
- Population Genetics - how variation of trains in a population can lead to evolution
These three branches can be studied in three contexts:
- Bacteria
- Archaea
- Eukaryotes
Likewise, in the context of
- Evolution
- Deisease and health
- Society
Course concept:
- Flipped Classroom
- Team Based Learning
Terms
gene
chromosome
DNA
RNA
Central Dogma: DNA is transcribed into mRNA. mRNA is translated into protein (trait). The protein can be thought of as a trait. This is a general guideline. There are variations in different cases.
DNA → RNA → protein
Transcription Translation
$$ \text{DNA} \rightarrow \text{mRNA} \rightarrow \text{protein} $$
$$ \ce{DNA -> mRNA -> protein} $$
DNA is drawn as a double helix.
Gene is a piece of the DNA chain.
Gene Glut2 → protein Glut2
Glut2 protein is a receptor on the outside of a cell that brings glucose into the cell.
genetic variation = differences in inherited traits found in individuals in a population
example: Glut2 mutation where glucose enters the cell less efficiently. This mutation is associated with Diabetes Type II.
Genotype → → Phenotype
gene expression
transcription
- DNA in a gene is copied to produce an RNA transcript called messenger RNA (mRNA). This is carred out by an enzyme called RNA polymerase which uses available bases from the nucleus of the cell to form the mRNA.
translation
Gene Transfer
Gene transfer - the transfer of genetic information between organisms. Can be vertical or horizontal.
Vertical gene transfer is better known as sexual reproduction, from parent to offspring.
Horizontal gene transfer is directly from one organism to another.
Sexual Reproduction
vertical gene transfer
translation
Horizontal Gene Transfer (HGT)
aka Lateral Gene Transfer (LGT)
mechanisms
- transformation
- transduction
- conjugation
Genetic Engineering
Gene delivery = artificial HGT
Notes
The cell nucleus contains 46 chromosomes, 23 pairs, 22 non-sexual, 21 sexual. One chromosome is a long strand of DNA. DNA is a protein. A section of DNA is named a gene. A gene defines a trait.
The human body is made of proteins. Types of proteins: Membrane DNA
One DNA molecule IE 1 chromosome contains billions of atoms arranged in pairs.one DNA molecule contains hundreds or thousands of genes. New line Gene expression The gene causes a protein molecule to be created.
We want to understand intelligence. Intelligence is related to thought. our best guess is that intelligence and thought are functions of the brain. To understand the brain we study neurology and psychology. Neurology requires an understanding of neurotransmitters and hormones which are proteins. To understand proteins we must and understand basic chemistry, how atoms combine to molecules. A protein is a molecule.
Furthermore one aspect of AI is named genetic algorithms. to understand these algorithms we need and understanding of genetics.
Crispr, Casp competition every two years, AlphaFold from deep mind wins the competition,
CRISPR, gene editing animation https://youtu.be/4YKFw2KZA5o
DNA, the blueprint of life, how does it work
https://www.youtube.com/watch?v=zwibgNGe4aY
Sapolsky Molecular Genetics I https://www.youtube.com/watch?v=_dRXA1_e30o&list=PL150326949691B199&index=6
Biological Molecules
Macromolecules
carbohydrates, lipids, proteins, and nucleic acids
Biological macromolecules are organic, meaning that they contain carbon. In addition, they may contain hydrogen, oxygen, nitrogen, phosphorus, sulfur, and additional minor elements.
Carbon
$$\require{mhchem}$$
$\ce{CH4}$ = methane, the simplest organic carbon molecule
Figure 2.13 These examples show three molecules (found in living organisms) that contain carbon atoms bonded in various ways to other carbon atoms and the atoms of other elements.
(a) This molecule of stearic acid has a long chain of carbon atoms.
$$\ce{C17H35CO2H}$$
(b) Glycine, a component of proteins, contains carbon, nitrogen, oxygen, and hydrogen atoms.
© Glucose, a sugar, has a ring of carbon atoms and one oxygen atom.
Proteins
Protein Functions
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Functions:
- structural, hold the shape of cells together
- messengers, hormones, neurotransmitters, fit into other things, lock and key
- enzymes - catalyze reactions
- shape, changing to effect function, as in channel
Protein Structure
made up of amino acids, approximately 20 different amino acids
Protein Synthesis
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genes specify proteins
made up of amino acids, approximately 20 different amino acids, each amino acid coded for with a different DNA sequence
DNA sequence
three letters, three nucleotides
DNA codes for amino acids
a string of DNA coding for a sequence of amino acids, which get plugged together to create a protein
RNA, an intermediary step (between DNA and protein)
if you know the sequence of DNA:
- you will know the sequence of RNA
- you will know the amino acid sequence
- you will know the protein that thus is made
- you will know the shape of the protein
- you will know the function of the protein
everything about protein function is built around shape
every effector protein fits into another effector protein like a “lock and key”, hormones, neurotransmitters
amino acids, attracted to or repelled from, water hydrophillic, hydrophobic amino acids are mostly swimming in water the sequence of amino acids determines the shape, based on the way amino acids fit together
(all enzymes are proteins)
enzymes, catalyze a reaction, pulling something apart, or putting two things together
this is done with a change in shape by the protein
channel
four examples of a protein that changes shape to accomplish it's function
- enzyme to break apart two things
- enzyme to put two things together
- channel, open or close to allow an ion through the cell wall
- motor
Central Dogma
13:00
DNA → RNA → Protein
“DNA is running everything”. no. DNA knows everything.
1970's Central Dogma denied
discovery of RNA-based viruses
17:00
micromutations
one letter is changed, miscopied, changed by radiation, etc.
three base pairs
Resources
What is gene expression? https://www.yourgenome.org/facts/what-is-gene-expression#:~:text=Gene%20expression%20is%20the%20process,it%20is%20called%20gene%20expression%3F.
Robert Sapolsky: Human Behavioral Biology, lectures 4-9, https://www.youtube.com/watch?v=_dRXA1_e30o&index=4&list=PL150326949691B199
Eric Lander: DNA Replication, MIT Fundamentals of Biology https://www.youtube.com/watch?v=DRBREvFL19g
Steven Gorsich, Central Michigan University: Introduction to Genetics, https://youtu.be/5Ez_NVQ5BY4
