Biology Key Points Unit 2 Biological Molecules For Entry Test

Biology key points Unit 2 Biological Molecules for MDCAT entry test preparation. part 1 unit 2 important key points notes. Biological molecules are the chemical parts that makeup living things. They are very important to the way the human body works. All living things, from cells to organs, are made of biochemical compounds.

Just like every other living thing on Earth, we need them to live, work, and grow. This article goes over some important facts about biological molecules that will help you do well on the 11th-grade FSC Biology test.

Aromatic compounds:

What’s so great about them? Aromatic compounds aren’t just about smell and taste; we can find them everywhere. They are very important for plants, animals, and even people (look at our mood ring!).

They can also be good for our health, but only in small amounts. On the other hand, many aromatic compounds are dangerous in high doses, so enzymes must break them down before our bodies can use them. Let’s take a look at a few of these cool chemicals.

Biology Key Points Unit 2 Notes


  1. Biochemistry is the study of biological molecules.
  2. Carbohydrates
  3. Lipids
  4. Proteins
  5. Nucleic acid
ContentsBacterial cell           Mammalian cell
DNA 10.25
  • Approximate chemical percent composition of a bacterial and a Mammalian cell
  • Water is a polar molecule due to which it dissolves almost all types of polar substances and is therefore regarded as the universal solvent.
  • Specific heat is the amount of heat energy required to raise the temperature of one gram of water by one degree Celsius.
  • Water has high specific heat.
  • Water also has a high heat of vaporization.
  • The heat of vaporization of water is the heat required to convert one gram of liquid water into vapors to Get its boiling point.
  • The high heat of vaporization helps animals and plants to get rid of excess body heat during sweating and transpiration respectively.
  • The presence of hydrogen bonds among the water molecules causes water to remain liquid
  • Without hydrogen bonds, water would boil at -80 “C and would freeze at
  • -100 C.
  • Carbohydrates are polyhydroxy aldehydes or ketones.
  • Monosaccharides are the simplest carbohydrates that cannot be broken down into simpler ones. So they are a unit of carbohydrates.
  • They contain 3 to 7 carbon atoms
  • They are the sweetest carbohydrate.
  • They are easily soluble in water
  • They are commonly called sugar
  • The human body can only digest D- sugars (right-handed sugar).

Biology Important Points 11th Class:

Penultimate carbon is a carbon that is adjacent to the last carbon. For example in glucose, it is carbon no S but in ribose, it is carbon no 4.
22.0ligosaccharide: Carbohydrate which contains 2-10 monosaccharide are called oligosaccharide.

Disaccharides are the most common oligosaccharides.

The most common disaccharides are;
” Sucrose = glucose + fructose
” Maltose = glucose + glucose
” Lactose = glucose + galactose

  • Proteins are the most important biological molecules composed of C, H, and N, and sometimes sulfur (cysteine) and selenium (selenocysteine)
  • lt is the most abundant organic biological molecule present inside the cell (18% in the mammalian cell)

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