Lab Handout – Record your answers to the ATP lab using these papers
Name _________________________
Cell Energy: Using Models to Understand ATP
Part A – The Chemical Structure of Adenosine Triphosphate
ATP is made of smaller molecules or subunits – ribose, adenine and phosphate groups.
Section I: Ribose Molecule
1) What is the molecular formula of ribose? Fill in the appropriate subscripts by counting the number of
each type of atom:
C ____ H ____ O ____
2) How does the number of hydrogen atoms compare to the number of oxygen atoms in one molecule of
ribose? __________________________________________________________________________
3) How many carbon atoms are in a molecule of ribose? ______________________________________
Section II: Adenine Molecule
4) What is the molecular formula of adenine? Fill in the appropriate subscripts:
C ____ H ____ N ____
5) What element is in adenine that is not in carbohydrates (ribose)? ______________________________
6) What element is in carbohydrates that is not in adenine? ____________________________________
Section III: Phosphoric acid (Phosphate group)
7) What is the molecular formula of phosphate? Fill in the appropriate subscripts:
H ____ P ____ O ____
Section IV: Constructing an ATP Molecule
8) What does the prefix “tri” in triphosphate mean? __________________________________________
9) Where do the letters “aden” and “ine” come from? ________________________________________
10) What end parts did you remove from the adenine and ribose in order to fit them together? __________
11) Look at the end parts you removed; what molecule is formed when you combine these parts? _______
12) What end pieces must you first remove before you can combine these pieces? ____________________
13) What did you remove to make these connections? _________________________________________
14) How many of the molecules stated in Question 15 did you have to remove in order to create one
molecule of ATP? __________________________________________________________________
15) List the “building blocks” that are needed to form one ATP molecule in the table below. Indicate how
many of each you used to make one molecule of ATP.
Building Block
# Needed in ATP
16) Look back at the introduction; what substance is needed in order for these parts to combine? ________
Part B – Releasing Energy from ATP as it Changes to ADP
17) How many phosphate groups are still attached to the original molecule? ________________________
18) Look at this molecule to determine what the prefix “di” means. _______________________________
19) List the “building blocks” that are needed to form one ADP molecule. Indicate how many of each you
used to make your one molecule of ADP.
Building Block
# Needed in ADP
20) Explain how one ATP molecule is changed into one ADP molecule. ___________________________
21) Look back at the introduction; what substance is released when ADP is formed? __________________
For example, this change may be written as follows:
becomes
ATP
ADP + Phosphate group + E
22) What might the letter “E” be an abbreviation for in the above equation? ________________________
Part C – Changing ADP to ATP
ADP + Phosphate group + E
becomes
ATP
23) What might the letter “E” be an abbreviation for in the above equation? ________________________
Part D – An Energy Source for Converting ADP to ATP
24) Count and record the number of bonds in:
a. one molecule of glucose __________________________________________________________
b. two molecules of pyruvic acid _____________________________________________________
NOTE: Be sure to count double lines as two bonds and all other lines as one bond.
25) Is the total number of bonds in one glucose molecule the same as the total number of bonds in two
pyruvic acid molecules? _____________________________________________________________
26) Is the amount of energy in one glucose molecule the same as the energy in two pyruvic
acid molecules? _______________________________________________________________________
27) Look back at the introduction. How is some of this extra energy used by a cell? __________________
___________________________________________________________________________________
Data Analysis/Conclusion
28) List the name and number of each building block used in ATP and ADP. Fill in the table to the right.
Building Block
# Needed in ATP
# Needed in ADP
29) Compared to ADP, does ATP have:
a.
b.
c.
d.
a greater, fewer or equal number of phosphates? _______________________________________
a greater, fewer or equal number of ribose molecules? ___________________________________
a greater, fewer or equal number of adenine molecules? __________________________________
more, less or equal amount of energy stored in its bonds? ________________________________
30) Your muscles require energy to move your body. What food directly supplies your muscles with this
energy? __________________________________________________________________________
31) What process directly supplies your body with the energy it needs to change ADP back to ATP?
________________________________________________________________________________
32) What does the energy released from ATP get used for in a cell? ______________________
___________________________________________________________________________________
___________________________________________________________________________________
33) Changes from ATP to ADP and back again are often said to occur in a cycle as shown below. Energy is
both given off and used for work. Energy is also stored during cellular respiration. Complete the
diagram below by writing the phrases “energy given off” and “energy stored from respiration” in the
correct spaces.
ATP
ADP
+
Phosphate Group