Biochemistry WebQuest

In Biology we study the biochemical structure of living things. In this webquest you will learn some basic chemistry and then you will learn about the four macromolecules all living things are made of: carbohydrates, proteins, lipids, and nucleic acids!

PART I Basic Chemical Concepts

To review atomic structure go to:

  • ______- the smallest unit of an element that can combine chemically with other elements.
  • Structure
  • Proton: ______charged
  • Neutron: ______charged
  • Electron: ______charged
  • Electrons exist in distinct ______clouds
  • Protons and neutrons are the same ______and make up the nucleus
  • Identification
  • ______: the number of protons
  • Atomic mass number: number of ______+ neutrons
  • Atoms are organized into ______in the periodic table

Now go to to fill in the blanks

  • What are the six most common elements in living things?
  • What is the acronym to help us remember these elements?

Isotopes

Google the term Isotope and fill in the blanks:

  • Two atoms with the same ______number but different atomic mass numbers. Differ only in the number of ______. Some are ______(radioisotopes).
  • E.g. isotopes of hydrogen:
  • H-1 has a mass number of 1 and no neutrons
  • H-2 has a mass number of 2 and only one neutron
  • H-3 has a mass number of 3 and two neutrons
  • Go to and identify the following isotopes. How many neutrons are found in each isotope?
  • C-12
  • C-14

Compounds

Go to to learn about Lewis Dot Diagrams and bonding. Fill in the blanks:

  • Lewis dot structures are used to show how the atoms of a compound ______together.
  • Bonding occurs between ______electrons, electrons in the ______level of an atom.
  • Draw the Lewis dot structure for sodium (Na)
  • Draw the Lewis dot structure for selenium (Se)
  • Summarize the octet rule:

Use your bonding video notes to fill in the following:

  • Compound – a combination of two or more ______that are joined chemically
  • Ionic bond: when an atom will either give or take an ______from another atom
  • ______: a positive ion
  • Anion: a ______ion
  • ______forces hold the atoms together

Go back to

  • Draw the ionic bond between Na and Cl (table salt)
  • Covalent bond: when atoms ______electrons
  • Form single, ______, or triple bonds
  • Sharing of ______holds the atoms together
  • Draw the Lewis dot diagram for water, carbon dioxide, and nitrogen gas (you might have to google them!)
  • Polar and non-polar covalent bonds: Go to
  • Some covalently bonded molecules like hydrogen fluoride gas (HF) do not share electrons equally. One of the atoms pulls harder on the shared electrons. Covalent molecules with this type of uneven charge distribution are called ______bonds.
  • Molecules with polar covalent bonds have a positive and a ______side.
  • Click on the dog analogies to watch the three types of bonds!

PART II Macromolecules

Carbohydrates Tutorial

Click on the link provided and read the tutorial about carbohydrates. You may need to scroll up and down on the small screen at the top of the tutorial for more information. When you finish go to Step 2 Lipids.

Internet Links: Carbohydrates

  1. Carbohydrates provide the raw fuel for ______.
  2. Give 3 examples of monosaccharides.

a.

b.

c.

  1. ______is the 6 carbon sugar found in blood.
  2. ______is the sugar that sweetens fruit.
  3. ______is the sugar found in milk.
  4. Glucose can have a straight line of carbon atoms or form a ______structure.
  5. The 5 carbon sugars called pentose are used in nucleic acid synthesis are ______and ______.
  6. Give 3 examples of disaccharides.

a.

b.

c.

9. Polysaccharides include ______, ______, and

______.

10. ______is the storage molecule made from glucose by plants.

11. ______is made by plants for cell wall construction.

12. Glycogen is the carbohydrate storage molecule found in ______and______.

Lipids Tutorial

Click on the link below and answer the questions on your sheet about lipids. When you finish the lipid portion on your worksheet go to Step 3 to view Protein tutorial. Answer the questions on your sheet about Proteins.

Internet Links: Lipid

Lipid Tutorial

  1. Lipids are organic molecules that are ______in water.
  2. Give 3 examples of lipids.

a.

b.

c

3. Neutral fats are also called ______because they have 3

fatty acids.

4. Neutral fats 3 functions:

a.

b.

c

5. The building blocks of neutral fat molecules are ______and ______.

6. ______fatty acids originate form animal sources and are ______at room temperature.

7. ______fats originate from plants and are ______atroom temperature.

8. ______are the chief components of all cell membranes.

  1. ______helps to stabilize cell membranes and is used by thebody to break down steroids.

Protein Synthesis

Click on the Protein link below to view the Protein tutorial. Answer the questions on your Biochemistry worksheet while viewing tutorial. After you have finished go to the Step 4 link on Nucleic Acids (DNA).

Internet Links:

Protein Tutorial

1.Proteins make up ______% to ______% of cell mass.

2.Examples of proteins in an organism.

a.

b.

c.

d.

3. Proteins are built from ______common building blocks called ______.

4. The primary structure of protein is determined by the sequence of ______connected by ______bonds.

Nucleic Acids

DNA Tutorial

Internet Links:

Intro

  1. DNA comes with a complete set of ______to make an entire organism.
  2. Using only _____ letters the DNA molecule builds everything from a bug to a human.

Role of DNA

  1. While you are growing you need DNA to produce more ______.
  2. As an adult you also need DNA to :

a.

b.

c.

The Cell

  1. DNA directs the entire operation by issuing instructions to make things you need such as______.
  2. DNA allows organisms to make ______of themselves which is a requisite of life.

Chromosomes

  1. Inside the nucleus you find DNA packaged into ______.

8. You get 1 set of chromosomes from your ______and 1 set of chromosomes from your ______.

9. Each cell has ______chromosomes arranged into ______pairs.

Watson and Crick

  1. What are the 4 nitrogen bases found in DNA?

a.

b.

c.

d.

11. What is the shape of DNA? ______

  1. Now use Google to find three differences between DNA and RNA:

Summary

Go to

Draw the structure of the following molecules:

  • Carbohydrate
  • Lipid
  • Protein
  • Nucleic acid (DNA)