Chemistry of Life

Keegan Hart

Macromolecules and Water


Water Molecule

why is water so important? It is so important that scientist look for it on other planets to see if there could be life

The Water Molecule

  • covalently bonded
  • dihydrogen monoxide H2O
  • unequally shared electrons cause the molecule to have slight charges on the ends

Hydrogen Bonding

since the ends of the molecule are slightly charged, weak bonds can form between the positive end of one molecule and the negative end of another

other molecules do this too. In water, the hydrogen bond leads to other characteristics.

Adhesion-attraction of H2O molecules to other substances.

Wicking- water will move up substances due to capillary action (water and pants leg.)

Cohesion- attraction of water molecules to each other. This is called surface tension. (droplets, water striders.)

Heat Storage:

  • water can hold a lot of energy in it. It takes a long time to warm up and cool down
  • how does this help us? ex: sweating, cool sea breeze)

Density as a solid:

water is the only substance that is less dense as a solid then as a liquid, so it floats

pH scale: water can cause separation in solutions leaving H+ and OH. ions causing solutions to be more acidic or basic.

Nucleic Acids (Dna/Rna)

-they carry our genetic information

-theyre code for amino acids (proteins)

-molecular currency of energy transfer in cells

-phosphate bonds contain a lot of potential energy


Whats a carbohydrate

-organic compounds made of hydrogen (H), carbon (c) and oxygen

-ratio of C to H to O is 2:1

-key source in most foods

biological importance of carbohydrates

-energy stores (4 calories/gram)

-structural (ie. cellulose in plants.)

-regulation of protein cell interactions.

-defense against invading viruses and bacteria

types of carbohydrates


  • basic source of energy for cells
  • mono=1 sacch=sweet and sugar (ex: glucose, fructose [fruit sugar])


  • a chain of 2 monosaccharides linked together by a covalent bond
  • di=2 sacch= sweet sugar
  • needs tobe digested by the human body to be used in cells
  • ex:sucrose (table sugar) lactase.


  • carbohydrates structures that contain more than 2 but less than 20 manosaccharide units.
  • monnose oligosaccharides cover the head of HIV. the monnose then shields


  • a chain of 3 or more monosaccharides
  • poly=many sacch=sweet, sugar
  • can be very large; a macromolecule
  • stores plant energy; needs to be digested by the human body
  • ex: starches, cellulose, chitin



  • make up cell membranes
  • long term energy

Saturated fat:

  • long chain or chain with all bonds filled by hydrogen
  • solid at room temperature
  • unsaturated fats have one double bond mono which cause a kink in the chain that does not allow the fat to solidify


-needed for function of organs

-made of amino acids

-enzymes are proteins who help carry out chemical reactions to take place

-enzymes help carry out the formation of new molecules by reading the genetic information carried out in DNA.



Macromolecules are molecules found in most foods and include Carbohydrates, Proteins, Nucleic Acids, and Lipids.

polymers monomers


Lipids------------------------------ fatty acids

proteins---------------------------amino acids

nucleic acid (rna/dna)-------- nucleotides