SBI4U Biochemistry
The Chemical Basis of Life – A Biology Prerequisite
Chemistry is an important component of your understanding in SBI4U. The following questions
are a brief review of the chemical concepts covered in grade 11 biology and chemistry
courses. The most effective way to complete this diagnostic assessment is to try to answer the
questions that you know first, and then refer to your textbook/course notes for details or
understanding of those gaps. Good Luck!
1. Create a VENN DIAGRAM comparing:
a. atoms & molecules
b. elements and compounds
2. Give five examples of EACH - elements and compounds that are found in the human body.
3. Draw a representative (chemistry appropriate) diagram of a BIOLOGICAL atom showing
your placement of protons, neutrons, and electrons.
4. a) Carbon-14 is considered to be an isotope of carbon. What does this mean? Draw a Bohr
diagrams to represent it.
b) How is carbon-14 different than some other isotopes? What happens to it over time?
c) Define half-life.
d) What are three biological uses of isotopes?
SBI4U Biochemistry
5. Distinguish between an energy level and an orbital? What is an orbital’s maximum
capacity?
6. What are valence electrons? Why are they particularly of interest to scientists?
7. Show a biological element with a Lewis dot diagram.
8. a) What is meant when we say an atom is neutral?
b) What is an ion? Describe its electron arrangement.
c) Differentiate between a cation and anion.
d) Give 5 examples of ions found in the human body.
9. a) Create a small CONCEPT MAP on a separate piece of paper illustrating your current
understanding of chemical bonding. Start with the following terms in your parking lot and
then add additional ones as you deem fit.
ionic bonding
polar covalent
compounds
electron sharing
electronegativity
covalent bonding
attractive force
metal
electron transfer
valence electrons
pure covalent
elements
non-metal
ions
stable octet
For those with grade 12 chemistry in your back pocket, include the use of:
intermolecular force
intramolecular force
hydrogen bonding
London force
Dipole-dipole force
hydrophobic interaction
SBI4U Biochemistry
b) Why is chemical bonding an important term for biologists to understand?
10. State the type of bonding that is taking place (pure covalent, polar
covalent, ionic) in the following particles. Visually demonstrate the bonding by using
an appropriate bonding diagram. a) O2
c) NaCl
b) H2O d) CH4
11. What happens to orbitals of different atoms during bonding? Why is this significant with
respect to the molecule?
12. What does it mean if a molecule is polar?
13. How can a molecule have polar covalent bonds but be classified as non-polar?
14. Why would polarity be an important idea for biologists to understand?
15. Differentiate between an intermolecular and intramolecular force. Give an example
of each.
SBI4U Biochemistry
16. a) Differentiate between an acid and base.
b) What does pH mean?
c) Draw and label the pH scale demonstrating where the acids would be found, and
where the bases would be found.
d) What is the approximate pH of your stomach? blood? small intestine?
e) What is a hydronium ion? Why is it technically incorrect to call a hydronium ion a
hydrogen ion?
f) What is it called when an acid is added to a base in equal proportions? Provide a
sample equation. Identify the products.
g) What is the difference between a strong acid and a weak acid?