Molecules of Life Note Taking Guide

  1. Define polymer and monomer.
  1. Draw a model that illustrates how monomers are joined together to form polymers. What is this process called?
  1. Draw a model that illustrates how polymers are broken down to form monomers. What is this process called?
  1. Complete the following table:

Molecules of Life

Molecule / Monomers / Elements Present / Biological Function / Common Examples

CARBOHYDRATES

  1. What is the common name for carbohydrates? What suffix is a clue that you are dealing with a carbohydrate?
  1. What is the ratio of carbon to hydrogen to oxygen?
  1. What is the main function of carbohydrates for cells?
  1. Compare and contrast monosaccharides, disaccharides, and polysaccharides

Four VITALLY IMPORTANT monosaccharides are:

A. glucose – product of photosynthesis; reactant of respiration

B. fructose – fruit sugar; sweetest of all sugars; sugar of honey

C. galactose – component of milk sugar

D. ribose – component of DNA and RNA nucleotides

  1. Draw the linear form of the glucose molecule. Now redraw the glucose molecule in ring form.
  1. Draw galactose and fructose. Explain why they are isomers of each other and of glucose, and name what type of isomers they are. Highlight and label a carbonyl group. Highlight and label a hydroxyl group. Which of the two is a ketone? Which of the two is an aldehyde?
  1. Monosaccharides, especially ______, are the source of ______for cellular work. In addition, the carbon skeletons of monosaccharides provide the ______for building other organic molecules like amino acids and fatty acids.
  1. Name three common disaccharides and describe where they are commonly found.

A.

B.

C.

  1. Draw the ring form of glucose and fructose. Illustrate how they are joined to form sucrose.
  1. Polysaccharides perform two major functions for cells. They are:

A.

B.

  1. In what ways do polysaccharides differ from the smaller carbohydrates?
  1. Using a potato plant as an example, explain how starch is formed.
  1. Draw the ring structure of 4  glucose molecules. Illustrate how they are bonded to form starch. Identify the type of reaction that occurred to create starch.
  1. While plants store their excess glucose in the form of starch, animals store it in a different form. What is it?

Where is it generally found in humans?

  1. The most abundant organic compound on earth is a structural polysaccharide produced by plants. Name it.
  1. Draw the ring structure of 4  glucose molecules. Illustrate how they are bonded to form cellulose.
  1. Explain how the structure of cellulose makes it such a strong building material.
  1. Even though starch and cellulose and chemically similar, humans can digest starch but not cellulose. Explain why this is true.
  1. Where is the polysaccharide, chitin, commonly found?
  1. What is the most significant molecular difference between the monomers of chitin and the monomers of starch, glycogen, and cellulose?

Lipids

  1. Lipids vary greatly in structure & function. What trait unites all lipids and what structural characteristic accounts for this property?

The three most biologically important families of lipids are...

A. fats

B. phospholipids

C. steroids

  1. Fats are known as triglycerides or triacylglycerols. Describe the chemical composition of a fat.
  1. Use the chart below to compare and contrast (include a diagram!) of saturated and unsaturated fats.

Saturated FatsUnsaturated Fats

  1. A diet rich in saturated fats can lead to cardiovascular disease. Why do we need fats at all?
  1. How is the structure of a phospholipid molecule different from that of a triglyceride molecule?
  1. Describe how phospholipids behave when they are in contact with water. Why is this such a great adaptation for the structural molecules of plasma membranes?
  1. Draw the characteristic structure of a steroid.
  1. Cholesterol is a vital steroid. Explain its critical importance to vertebrates.

NUCLEIC ACIDS

  1. Name the two nucleic acids.
  1. What critical life role is accomplished by nucleic acids?
  1. The monomers of nucleic acids are called ______. The 3 parts of the monomers are

A.

B.

C.

  1. What role do hydrogen bonds play in the DNA molecule?