Question

procedure
part a. the chemical structure of adenosine triphosphate (atp)
atp is made up of smaller molecules of subunits - ribose, adenine, and phosphoric acid (or phosphate groups).
i. ribose molecule
examine the structural formula of ribose. ribose is a carbohydrate, or a sugar. it is different from glucose in one very important way. glucose has six atoms of carbon in each molecule, and has the chemical formula ( c_6h_{12}o_6 ). keep this in mind when answering the following questions.
based on its name, how do we know that ribose is a carbohydrate, or sugar?
the molecular formula of glucose is ( c_6h_{12}o_6 ). notice that the number of atoms of each element present is written as a subscript. now you try it! looking at the ribose molecule above, what is the molecular formula of ribose? (hint: count the # of atoms of each!).
ribose: ( c_5h_{10}o_5 )
how does the number of hydrogen atoms compare to the number of oxygen atoms in ribose?
in observing the molecular formulas of both glucose & ribose, what difference do you observe about the two molecules?

Explanation:

Step1: Determine the molecular formula of ribose

Count the number of carbon (C), hydrogen (H), and oxygen (O) atoms in the ribose molecule.

• Carbon atoms: 5
• Hydrogen atoms: 10
• Oxygen atoms: 5

So the molecular formula is \(C_{5}H_{10}O_{5}\).

Step2: Compare hydrogen and oxygen atoms in ribose

In \(C_{5}H_{10}O_{5}\), the number of hydrogen atoms (\(H = 10\)) is twice the number of oxygen atoms (\(O=5\)), i.e., \(H = 2\times O\).

Step3: Compare glucose (\(C_{6}H_{12}O_{6}\)) and ribose (\(C_{5}H_{10}O_{5}\))

• Glucose has 6 carbon atoms, while ribose has 5 carbon atoms.
• The general ratio of \(C:H:O\) is \(1:2:1\) for both (e.g., glucose \(6:12:6 = 1:2:1\), ribose \(5:10:5=1:2:1\)), but the total number of each atom is different.

Answer:

• Molecular formula of ribose: \(C_{5}H_{10}O_{5}\)
• Hydrogen - oxygen comparison: The number of hydrogen atoms is twice the number of oxygen atoms.
• Difference between glucose and ribose: Glucose has 6 carbon atoms, ribose has 5 carbon atoms (also, total number of \(C\), \(H\), \(O\) atoms is different while maintaining \(C:H:O = 1:2:1\) ratio).