amateurchemstudent
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Latest Posts by amateurchemstudent
#Thunderstorms are hitting the UK this week – here’s how thunder and lightning happen and some of the chemistry going on during a storm: https://ift.tt/2XUCKZc https://ift.tt/3gJ7ALD
Plenty of opportunities to wear sunglasses this week! 😎 Here’s the science behind how the protect your eyes from the sun’s UV radiation in C&EN: https://ift.tt/2XW7h8L https://ift.tt/3gT8PI6
Linus Pauling was born #OTD in 1901. He’s best known for his work on chemical bonding and the electronegativity scale that bears his name, for which he won a Nobel Prize. Just don’t mention the vitamin C years 😉 https://ift.tt/3uFpNkF https://ift.tt/3r4nm98
Around a year ago, scientists determined the structure of the SARS-CoV-2 spike protein. Here’s a look at how it was done and how it helped the fight against #COVID19 in the latest edition of #ChemVsCOVID with the Royal Society of Chemistry: https://ift.tt/3pZiZe9 https://ift.tt/3002NPh
#OTD a year ago, Moderna’s RNA vaccine became the first #COVID19 vaccine to enter phase 1 trials. The latest #ChemVsCOVID graphic with the Royal Society of Chemistry takes a brief look at how prior research helped COVID vaccines reach this point quickly: https://ift.tt/3cE5xHR https://ift.tt/3rV4v0F
Slice of Life
It’s World Sleep Day
Log off.
Go back to bed.
What comes to mind when you think of alcohol? Probably alcoholic drinks like beer or wine. But in organic chemistry alcohols are an important and versatile family of compounds. In this episode of Crash Course Organic Chemistry, we’ll use alcohols as a starting point to get other types of compounds like ethers, epoxides, and more!
Follow @productive-tips for more tips and content like this posted daily! Handpicked and curated with love :)
Follow @productive-tips for more tips and content like this posted daily! Handpicked and curated with love :)
🌻 little habits/things to do more of 🌻
dailies
make your bed. (no, really.)
set your top 3 to-dos for the day.
do your top 3 to-dos for the day. (heh)
stretch.
unpack your bag when you get home.
prepare your things for the next day before sleeping.
skincare. (your basic cleanse and moisturize)
sweep the floor of your bedroom.
talk to your plants. (if you have plants)
update your financial report/expense tracker.
take a good photo.
meditate.
hug at least three people. (seriously.)
weeklies
polish your school shoes.
mop your bedroom floor.
dare i say, laundry. (don’t put it off!)
exfoliate.
take a leisure walk.
review your past week and plan your next week accordingly. (a part of your routine may not be working–try something new)
make a piece of art. (a sketch, a collage, a quote in pretty lettering, a god-awful poem..)
sanitize your gadgets. (whip out the wet tissue and wipe away at your phone, your laptop, your mouse, your earphones–just don’t forget to IMMEDIATELY follow that up with a dry cloth to prevent fogging and short circuits)
watch a TED Talk.
make a new playlist.
monthlies
wash your bag.
wash your shoes.
change the sheets of your bed and your pillows.
clip your nails. (honestly)
wax/shave. (if you want. i just really like how fresh my skin feels after i torture it with razors and wax strips)
wipe your shelves/the tops of your furniture clean. (try to avoid dusting. it just scatters the dirt everywhere. use a damp cloth instead)
see if there’s anything in your storage that you don’t need/want anymore and give stuff away or sell them.
review your month and plan the next one accordingly. (just like your weeks. remember to refer to your Life Goal/Year’s Goals page)
finish reading at least one book. (and review it!)
discover new songs.
- 🍂
My friend sent this to her Professor today
Alkanes: Crash Course Organic Chemistry #6:
Alkanes are kind of the wallflowers of organic chemistry, but they still have important functions in the world around us. In this episode of Crash Course Organic Chemistry we’re building our knowledge of organic molecules by learning all about these so called couch potatoes from how they are separated from crude oil to how to use Newman projections to predict torsional strain and steric hinderance. We’ll also learn the names of some common conformers and get an introduction to cycloalkanes.
Good news! You CAN rewire your brain. Through the same mechanism as forming habits, you can change your automatic thought patterns. When you catch yourself with unhealthy thoughts, STOP, and make a conscious effort to replace that thought pattern with a more beneficial/healthy thought pattern. Keep doing that whenever those thoughts occur. Slowly but surely your mind’s default voice will match what you’re teaching it.
Follow @productive-tips for more tips and content like this posted daily! Handpicked and curated with love :)
The two kinds of water
Credit: University of Basel
Pre-sorted ortho-water and para-water molecules with differently oriented nuclear spins (blue or red arrows) react with diazenylium ions (centre left) at different speeds.
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Researchers from the University of Basel’s Department of Chemistry, Switzerland, has investigated how the two forms of water differ in terms of their chemical reactivity – the ability to undergo a chemical reaction. Both forms have almost identical physical properties, which makes their separation particularly challenging.
It is less well-known that water exists in two different forms (isomers) at the molecular level. The difference is in the relative orientation of the nuclear spins of the two hydrogen atoms. Depending on whether the spins are aligned in the same or opposite direction, one refers to ortho- or para-water.
The was made possible by a method based on electric fields. Using this, researchers were able to initiate controlled reactions between the pre-sorted water isomers and ultracold diazenylium ions (protonated nitrogen) held in a trap. During this process, a diazenylium ion transfers its proton to a water molecule. This reaction is also observed in the chemistry of interstellar space.
It was discovered that para-water reacts about 25% faster than ortho-water. This can be explained in terms of the nuclear spin also influencing the rotation of the water molecules. As a result, different attractive forces act between the reaction partners. Para-water is able to attract its reaction partner more strongly than the ortho-form, which leads to an increased chemical reactivity.
Biochemistry
Update: Pictures are working!
Atoms
There are a few basic chemistry concepts that are essential to understand. For starters, understanding what an atom is and its basic properties.
Atoms are the building block of all matter. They have a positive nucleus, with positive protons, and neutral neutrons. In a large area surrounding the nucleus, is the electron cloud, made of negatively charged electrons.
An atom in its elemental state is always neutral.
When an element has a charge, it is because it has an unequal number of protons an electrons, making it an ion. Sometimes an element’s nucleus has an unequal number of neutrons and protons, making it an isotope. Carbon-14, for example, has 8 neutrons, instead of the 6 that Carbon-12 has. Carbon-14 is also a radioisotope, meaning it emits particles and decays at a rate called a half-life, making it useful for fossil dating. Along with that, radioactive carbon can be used as a tracer. This means it is incorporated in CO2 molecules and used to track metabolic pathways.
The location of the electron affects how the atom will react with other elements. When electrons are in the lowest available energy level, they are in the ground state. When they absorb energy, they move to a higher energy level, entering the excited state. For instance, when chlorophyll absorbs light energy, electrons within it are boosted to higher energy levels. This provides the energy necessary to produce sugar when they return to their ground state level as they release the energy they absorbed.
Bonding
Elements bond when two nuclei are attracted to each other. Energy is released when a bond is formed. All atoms want to either get rid of all their electrons on their outer shell or fill their outer shell with 8 (or in hydrogen’s case, 2) electrons, which makes them stable. There are 3 kinds of bonds, but for biochemistry, Ionic and covalent bonds are what is relevant.
Ionic bonds form ions (hence the name.) They occur when electrons are transferred. The atom that gains electrons becomes a negatively charged anion. The atom that loses electrons becomes a positively charged cation.
Covalent bonds are made when electrons are shared. This occurs when the two atoms have electronegativities that are closer together than in an ionic bond. Electronegativity is the tendency of an atom to pull electrons towards it. These bonds can be polar if the electronegativity is high enough. A polar molecule is a molecule with a partial charge. For example, water is a polar molecule, as oxygen is extremely electronegative, and water is partially electronegative.
Hydrogen Bonding
Hydrogen bonding is a specific kind of intermolecular force that is essential to life. It is what keeps the 2 strands of DNA bonded together, and gives water its unique characteristics. Since oxygen has a partial negative charge, and hydrogen has a partial positive charge, they are naturally drawn to each other.
Hydrophobic vs Hydrophilic
Polar molecules are hydrophilic. This is because they are attracted to the partially charged ends of water. Hydrophilic means they are attracted to water. (Not in that way… sick) NaCl or table salt is hydrophilic. This is why salt dissolves in water.
Non-polar molecules are hydrophobic. This means they are repelled by water. (They’re filthy water haters.) Lipids are hydrophobic, which is why fats and oils do not dissolve in water.
The cell membrane is a phospholipid bilayer, only allowing nonpolar substances to dissolve through it. Large polar molecules have to use specific hydrophilic channels.
Characteristics of Water
Water is a unique molecule, and without its unique properties, life on earth would not exist as it does, or even at all.
Water has a high specific heat: Because hydrogen bonds are so strong, it requires a lot of heat energy to break them. This is why large bodies of water remain the same temperature, and why coastal cities have a consistent temperature because the water absorbs all the heat energy before it can warm up.
Water has a high heat of vaporisation: A large amount of energy is needed for water to vaporise, which is why sweating is such an effective cooling method.
Water has high adhesion properties: Adhesion is when one substance clings to another. Adhesion causes capillary action, which occurs in the xylem of plants, and is used to bring water up from the roots without expending energy.
Water is a universal solvent: Due to its high polarity, water makes an excellent solvent.
Water is extremely cohesive: Molecules of water tend to stick to each other. This is observed in surface tension and allows for small insects to run across the surface of the water. Cohesion is also necessary to bring water up from the roots, by transpirational-pull cohesion tension.
Ice is less dense than water: Instead of freezing all the way through, ice crystallises, leaving large amounts of space, causing ice to float. This is essential for the survival of marine life during the winter, as they can live beneath the ice.
pH
pH is calculated by taking the -log of the chance of finding hydronium (H30+) ions within a certain amount of water. Hydronium is made in rare circumstances, where a hydrogen ion breaks off from a water molecule. Normally, there is a 1 in 10 million chance of there being a hydronium ion. This is the equivalent of 1x10^-7. The -log of this number is 7, the neutral pH.
Any pH below 7 is acidic. Any pH above 7 is basic. Stomach acid has a pH of 2, while bleach has a pH of 11. Human blood has a pH of around 7.4
Most living cells need to have an internal environment with a pH of around 7. Buffers exist to regulate pH by either absorbing excess hydrogen ions or donating missing hydrogen ions. In human blood, the bicarbonate ion (HCO3) is essential.
Macromolecules
There are 4 types of macromolecules: carbohydrates, lipids, proteins, and nucleic acids.
Carbohydrates
Carbohydrates are made of carbon, hydrogen, and oxygen. They supply quick and easy energy. 1 gram of all carbohydrates will release 4 calories of energy. In our diet, they can be found almost everywhere in foods such as rice, pasta, bread, cookies, etc.
There are 3 kinds of carbohydrates: monosaccharides, disaccharides, and polysaccharides.
Monosaccharides
All monosaccharides have a chemical formula of C6H12O6. It is the placement of the carbon, oxygen, and hydrogen that determines its properties. Glucose, fructose, and galactose are all examples. They are isomers, meaning they have the same chemical formula, but a different structure.
Disaccharides
When 2 monosaccharides join together, they create disaccharides. They all have the chemical formula C12H22O11. Dehydration synthesis is the process that creates them. This process releases 1 molecule of water, hence the name. Lactose, maltose, and sucrose are all examples.
Hydrolysis is the exact opposite of dehydration synthesis. It is used during digestion. One molecule of water is used to breakdown polymers into monomers.
Polysaccharides Polysaccharides are long polymers of carbohydrates. Cellulose (plant cell wall), chitin (exoskeleton, fungi cell wall), glycogen (how animals store carbohydrates) and starch (how plants store carbohydrates) are all examples.
Lipids
Lipids include fats, oils, and waxes. Most contain 1 glycerol and 3 fatty acids. Glycerol is alcohol.
Fatty acids are the building blocks of lipids and are hydrocarbon chains with carboxyl groups at the end. There are 2 varieties; saturated and unsaturated. (3 if you count trans-fats when extra hydrogen is added to the fat to make the lipid solid)
Saturated fats are solid at room temperature, and are famously unhealthy as they are linked to heart disease.
Unsaturated fats are liquid at room temperature and are good dietary fats.
Lipids store much more energy than carbohydrates. 1 gram of any lipid will release 9 calories of heat per gram. They can be structural, as in the phospholipids of the cell membrane, or they can be hormones.
Proteins
Proteins are polymers of amino acids linked together by peptide bonds.
Amino acids are identifiable by their carboxyl group, amine group, and variable R, attached to a central carbon atom.
Proteins are complex and perform a vast array of duties, such as growth and repair, being enzymes, membrane channels, and hormones.
1 gram of protein releases 4 calories of heat.
Proteins contain the elements C H O N P S
There are only 20 amino acids coding for the thousands of proteins in the human body.
Protein Structure
There are 4 levels to the structure of a protein.
The primary structure results from the sequence of amino acids making up the polypeptide
The secondary structure results from hydrogen bonding within the molecule. This causes a helical structure
The tertiary structure is an intricate 3-dimensional shape or conformation of a protein and most directly decides the function of the protein. Enzymes denature in high temperatures or in the wrong pH because the tertiary structure is compromised.
The quaternary structure is only found in proteins that have more than 1 polypeptide chain, such as in haemoglobin.
Enzymes
Enzymes are large proteins
Enzymes lower the energy of activation, speeding up the reaction, as it lowers the amount of energy needed to start the reaction.
The chemical an enzyme works on is known as a substrate
Enzymes are specifically designed for specific substrates. For example, lactase only works on lactose. Notice the naming pattern for enzymes and their substrates.
The induced fit model is an explanation for how they work. When the substrate enters the active site, it induces the enzyme to change its shape to fit the substrate.
Enzymes can be reused as they do not degrade during a reaction
Enzymes are assisted by cofactors (minerals) or coenzymes (vitamins)
Prions
Prions are proteins that cause diseases. Mad cow disease is an example. It is a misformed protein able to influence other proteins to fold in the same way.
Nucleic Acids
There are 2 kinds of nucleic acids: RNA and DNA. They are necessary for carrying genetic information.
Nucleic acids are polymers of nucleotides
The nucleotides are the two purines: Adenine and Guanine, and the 3 pyrimidines, Thymine, Uracil, and Cytosine. Uracil is only found in RNA, and thymine is only found in DNA. Adenine connects with thymine/uracil, and guanine connects with cytosine.
Polarity, Resonance, and Electron Pushing: Crash Course Organic Chemistry #10:
We’ve all heard the phrase “opposites attract.” It may or may not be true for people, but it’s definitely true in organic chemistry. In this episode of Crash Course Organic Chemistry, we’re learning about electronegativity, polarity, resonance structures, and resonance hybrids. We’ll practice a very important skill for this course that will help us avoid a lot of memorization in the future: electron pushing. It’ll be a lot of trial and error at first, but we all start somewhere!