Biological molecules 1

(Protein) Peptide

Short chains of amino acids (e.g., oxytocin)

(Protein) Polypeptide

Long chains of amino acids; has at least tertiary structure (e.g., human amylase)

(Carbohydrate) Monosaccaride

Simple sugars (including glucose and fructose)

Often are building blocks of larger molecules

(Carbohydrate) Disaccaride 

Composed of 2 simple sugar molecules attached to form a larger one

Examples = lactose, sucrose

(Carbohydrate) Polysaccaride 

Large molecules composed of simple sugar subunits (often glucose)

*Examples = starch, cellulose, glycogen, chitin

(Lipid) Unsaturated fat

• Non-polar

• Composed of 3 fatty acids bonded to glycerol

• *Fatty acid tails do not contain as many

  hydrogen atoms bonded to carbon as they

  potentially could (meaning some carbon

  atoms are double-bonded to others, making

  kinks in the tails)

• *Kinks in fatty acid tails mean the molecules

  cannot pack closely together --- substance

  remains liquid at room temperature

(Lipid) Wax

• Variable number of fatty acid tails bonded to an alcohol group

• *Fatty acid tails contain as many hydrogen

  atoms bonded to carbon as they potentially

  could (meaning that carbon atoms are all

  single-bonded to others, making their tails

  straight)

• *Straight fatty acid tails mean the molecules

  can pack closely together --- substance is thus

  solid at room temperature *Present in cuticle of plants, bee hives

(Lipid) Steroid

Non-polar Composed of 4 fused carbon rings and

different functional groups attached

(depending on type of molecule)

*Examples = cholesterol, estrogen,

testosterone

(Lipid) Saturated fat

• Non-polar Composed of 3 fatty acids bonded to glycerol

• Fatty acid tails contain as many hydrogen

atoms bonded to carbon as they potentially

could (meaning that carbon atoms are all

single-bonded to others, making their tails

straight)

• Straight fatty acid tails mean the molecules

can pack closely together --- substance is thus

solid at room temperature

(Lipids) Phospholipids

• Main component of cell membranes Contain a “head” region that is water-soluble

(contains a phosphate group with a negative

charge and a functional group that often has a

positive charge) and 2 fatty acid “tails” that

are non-polar and water-insoluble --- leads to

arrangement that helps give cell some control over what enters and leaves

(Nucleotides & nucleic acid) Ribonucleic acid

• Polynucleotide of ribose nucleotides

• Several types of this molecule work together

to bring about protein synthesis (i.e.,

translation)

(Nucleotides & nucleic acid) Nucleotide 

• Consist of 3 main components: a 5-carbon sugar (either ribose or deoxyribose) bonded to both a phosphate group (with variable number of phosphates)

• and 1 of 5 possible nitrogen-containing bases

Some function on their own (e.g., ATP) Some are monomers of larger molecules

(Nucleotides & nucleic acid) Deoxyribonucleic acid

• Polynucleotide of deoxyribose nucleotides Stores genetic information for how to make

and maintain an organism