bio1: Water, Proteins, Carbs, Fats, Vitamins and Minerals (v1.0)

This is the first in a series of essays on Biochemistry, Molecular Biology, and Cell Biology (Cytology). I will not really though dwell into the details of the chemical structure of any molecule in this series. A key reference for this series is Professor Kevin Ahern of Oregon State University. I will start off by drilling down on the four key ingredients of humans and their foods – Water, Amino Acids and Peptides and Proteins, Fats and Lipids, and Sugars and Carbohydrates. I will also touch on Vitamins and Minerals. I will also briefly mention hormones and enzymes. In this essay I won't talk much about the roles these chemicals play in our body or the composition of foods.  

Biochemistry is the branch of science concerned with the chemical and physicochemical processes and substances that occur within living organisms. It is a fascinating field that delves into the intricate molecular workings of living organisms. Biochemists aim to unravel the chemical basis underlying biological processes within cells. Biochemistry extends its reach to tissues and organs. Investigating energy production, storage, and utilization is another objective. Biochemistry also plays a crucial role in understanding diseases. Molecular biology is a branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. Cell biology (also cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells.

The body of a healthy lean man is composed of roughly 62% water, 16% fat, 16% protein, 6% minerals and less than 1% Carbohydrates.  It also has very small amounts of Vitamins and other miscellaneous substances. I will focus on these in this essay.

I will briefly touch on Minerals. The major minerals stored and used in the body in larger amounts are Calcium, Chloride, Magnesium, Phosphorous, Potassium, Sodium, and Sulfur. These major minerals are essential. Other trace minerals are just as vital to our health as the major minerals and mainly consists of Iron, Zinc, Iodine, Chromium, Copper, Cobalt (as part of vitamin B-12 only), Fluoride, Molybdenum, Manganese, and Selenium. I won’t dwell further on minerals. You can do further research on what the role of each of these minerals is in the body.

I will briefly touch on Vitamins. Vitamins are organic molecules (or a set of closely related molecules called vitamers) that are essential to an organism in small quantities for proper metabolic function. Vitamins A, D, E and K are fat soluble. The body stores them in fatty tissue and the liver. Vitamin C and all the B vitamins are water soluble and are not stored and pass out in the urine. Since it is not stored, people need a regular supply of water-soluble vitamins more than fat soluble vitamins. I won’t dwell further on Vitamins. You can do further research on what the role of each of these Vitamins is in the body. 

Water is an essential and irreplaceable part of all life. It is in the cells inside of us and in bodily fluids. All cellular processes involve water!!  Its key role in life is because of its unique properties in conditions like on earth.

  • ·        A liquid normally that expands on freezing.
  • ·        Is a polar molecule with a clear positive and negative charge side. 
  • ·        Forms hydrogen bonds across molecules and with other dissimilar molecules.
  • ·        An effective solvent for most hydrophilic compounds. 
  • ·        Slight ionization occurs so acts slightly both acidic and alkaline equally. 
  • ·        It affects the behavior of all other biological molecules. 

It is no accident that life first emerged in water! Blood is a fluid that supplies essential substances, such as sugars, oxygen, and hormones, to every cell and organ, and removes waste from the cells. It also fights sickness and does other crucial functions. So, it is vital. Blood is slightly alkaline and always has an acidity/alkaline measure called PH factor between 7.35 and 7.45 (7.0 is water – acidic and alkaline in equal balance). If it goes above 7.45 it is called alkalosis with corresponding symptoms. If it goes below 7.35 it is called acidosis with corresponding symptoms. PH below 6.8 or above 7.8 can result in death. Water plays a key role in stabilizing and preserving blood PH level through an effect called buffering. A buffer is a solution that can resist pH change upon the addition of acidic or basic components (you might have seen this in a chemistry lab in school during titration!). There are no evidence diet affects blood PH so don’t worry!! But keeping your body always hydrated is very important.  

The building blocks of proteins and peptides are amino acids. There are over 700 amino acids known but there are only 20 key amino acids your body needs to function properly. Part of the chemical structure of an amino acid is common to all. The varying part is called the radical or side chain. The common part consists of:

  • ·        A carbon atom
  • ·        A hydrogen atom
  • ·        A carboxyl group (COOH)
  • ·        An amino group (NH2)

If the radical contains only carbon and hydrogen atoms, then the amino acid is called aliphatic. If the radical contains an aromatic ring structure, it is called aromatic (you might have studied aromatic compounds like benzene in introductory organic chemistry in college). Some side chains have Sulphur. Half the amino acids are hydrophobic (repelled by water. Have side chains that are non-polar) and others are hydrophilic (love water. Have side chains that are polar).  Neutral amino acids are neither acidic nor alkaline but may be polar or non-polar. Nine of the amino acids are called essential. Essential amino acids must be consumed through the food you eat because the body does not produce at all or produce enough. Conditional essential amino acids are ones that must be consumed by diet when the body does not produce enough under certain physical or medical conditions. The 20 amino acids our body needs are:

  1. Alanine, (nonpolar, aliphatic)
  2. Arginine, (conditional essential, alkaline-polar)
  3. Asparagine, (polar, neutral)
  4. Aspartic Acid, (acidic-polar)
  5. Cysteine, (polar, conditional essential, contains Sulphur)
  6. Glutamine, (polar, conditional essential, neutral)
  7.  Glutamic Acid, (acidic-polar)
  8.  Glycine, (nonpolar, conditional essential, aliphatic)
  9. Histidine, (essential, aromatic, alkaline-polar)
  10. Isoleucine, (nonpolar, essential, aliphatic)
  11. Leucine, (nonpolar, essential, aliphatic)
  12. Lysine, (essential, alkaline-polar)
  13. Methionine, (nonpolar, essential, aliphatic, contains Sulphur)
  14. Phenylalanine, (nonpolar, essential, aromatic)
  15. Proline, (nonpolar, conditional essential, aliphatic)
  16. Serine, (polar, neutral)
  17. Threonine, (polar, essential, neutral)
  18. Tryptophan, (nonpolar, essential, aromatic)
  19. Tyrosine, (polar, aromatic)
  20. Valine. (nonpolar, essential, aliphatic)

 Amino acids are imperative for sustaining the health of a human body. If amino acids are deficient the protein synthesis would stop. Amino acids largely promote the:

  1. Hormones production
  2. muscle's structure
  3. Nervous system
  4. Vital organs working
  5. Cellular functioning.

Amino acids form bonds with other amino acids called peptide bonds which are covalent bonds. Polypeptide chains are chains of amino acids linked by peptide bonds and these chains fold into proteins. One end of a poly peptide chain is called the amino group and has nitrogen and two hydrogens (NH2). The other end is called the carboxyl group and contains a carbon atom with two oxygen atoms and also a hydrogen atom attached to one of the oxygen atoms (COOH).  The first amino acid seen at the start of all proteins is methionine. Cysteine Amino acids with Sulphur next to each other in protein folding also form disulfide bonds. You can do further research on what the role of proteins and peptides is in the body.  They have a gigantic role in the body!! I will drill down more into protein structure, and folding in a later essay. (URL: https://jaykasi.blogspot.com/2023/11/bio4-protein-synthesis-structure-and.html) The amino acids are like alphabets. With these alphabets you can form words, sentences, and paragraphs. This is similar to amino acids and poly peptides and proteins. Titin is the largest protein and has about 30,000 amino acids. It acts as a molecular spring that is responsible for the passive elasticity of muscle.

I will briefly touch on two extremely important chemicals called hormones and enzymes. Hormones are chemical messengers that coordinate different functions in your body. Several glands, organs and tissues make and release hormones, many of which make up your endocrine system. Hormones are typically proteins or steroids. Hormones are not enzymes. Enzymes are proteins that act as a catalyst in living organisms, regulating the rate at which chemical reactions proceed without itself being altered in the process. Biological processes that occur are chemical reactions and are mostly regulated by enzymes. I won’t dwell further on Hormones and Enzymes. You can do further research on what the role of each of them is in the body. Hormones are critical and I will talk about them more in a later essay. (URL: https://jaykasi.blogspot.com/2023/11/bio5-hormones.html)

As much as we worry about living with sugar, we cannot live without it. Sugars are a group of molecules with a particular chemical makeup. Sugars are one carbon atom for every water molecule multiplied by N (>=3) where N varies (CH2O) * N. The simplest sugars are also called monosaccharides and are the building blocks for higher carbohydrates. Examples of simple monosaccharides are glucose (N=6), fructose (N=6), Mannose (N=6) and galactose (N=6). Two monosaccharides combined is a disaccharide. Glucose + Galactose = Lactose. Glucose + Fructose = Sucrose. 3 to 10 simple sugars combined are called oligosaccharides. Combinations with more than 10 are called polysaccharides. Polysaccharides are also called complex carbohydrates and include important ones like fiber, starch and glycogen. Glycogen is a very important polysaccharide in animals as is starch and cellulose in plants. Sugars are an energy source for the body, but fats are an even higher energy source (twice as much). But sugar is a source for ready quick energy while fats are not. Sugars also are water soluble and can easily be transported to every cell while fats are not.

Every cell uses a crucial process called metabolism to release energy from sugars. Catabolism is the set of metabolic processes that break down complex molecules into smaller units. Example is complex carbohydrates to sugars, fatty acids to sugars or proteins to sugars. Protein breakdown is the theory behind high protein low sugar diets. A polysaccharide called Glycogen is made and stored by the liver and muscle. We only have enough energy stored in this Glycogen for just about 24 hours, so we need to get nourishment periodically. I will dwell more into metabolism in a later essay. (URL: https://jaykasi.blogspot.com/2023/11/bio3-metabolism.html)

Our main preoccupation with fat is losing it. But fats are part of a broader group called lipids that are essential to life. Two thirds of the brain is lipids!! Lipids include fats, oils, waxes, steroids, some hormones, and even some vitamins. Many have the same elements as carbohydrates. Others include nitrogen. Lipids have one part that is hydrophobic and overall are not hydrophilic but may be amphiphilic (comfortable with both water and oils). They don’t play in the same watery neighborhoods that other bio molecules do. Fats and cholesterol are very phobic about water. Lipids are not polymers like Proteins, Carbohydrates, and Nucleic acids. Their molecules are small.

Fatty acids are the smallest simplest lipids, and they are amphiphilic. In the body they are typically attached to a sugar molecule called glycerol. A glycerol with a bundle of three fatty acids attached is called a triglyceride. Triglycerides are completely hydrophobic and water insoluble. Fatty acids have a long hydrophobic carbon tail while the head is hydrophilic. Examples are stearic acid (18 carbon atoms in tail) and oleic acid (18 carbon atoms in tail). Fatty acids are saturated (no double bonds in carbon tail) or unsaturated. Unsaturated can be monounsaturated (one double bond only in carbon tail like oleic acid) or polyunsaturated (multiple double bonds in carbon tail like linoleic acid). If the double bond causes a kink in the tail, it is a cis fatty acid. Otherwise it is a trans fatty acid. Trans fatty acids occur in many industrially processed foods due to a process called partial hydrogenation. Trans fats can be bad for your cardiovascular health. Our body cannot make omega-3 and omega-6 polyunsaturated fatty acids so they must be obtained from the diet. Lipoproteins have an outer shell of protein and an inner shell of fat. HDL and LDL are lipoproteins (also called cholesterol). Elevated levels of cholesterol in the blood, especially when bound to LDL, may increase the risk of heart disease.  

Saturated fatty acids with straight tails can be packed and are solids at room temperature like butter. Most plant derived oils cannot be easily packed because they predominantly pack unsaturated fatty acids with kinks in their tails and are liquids at room temperature like olive oil. Coconut oil, while plant based, is predominantly made of saturated fatty acids and is solid at room temperature. All plant-based oils are a mix of fatty acid types.  

This essay describes the key chemicals that constitute our bodies or are created or consumed or used by it. Many of them are in our food. Nucleic acids are one more component in our bodies I did not cover. I will touch on it later.

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