Question

1. how many atoms of carbon are there in each molecule you now have (youll only have info for two) glucose? fructose? and galactose? 6. write the molecular formulas for your two molecules (c_h_o) glucose? fructose? and galactose? 7. compare the number of hydrogen atoms to the number of oxygen atoms in each sugar. what is the ratio of hydrogen to oxygen? (i.e., how many hydrogen atoms are there for each oxygen atom?) ____________ ; how do they compare to the ratio in water? 8. molecules of monosaccharides may have the same molecular formula but differ in three - dimensional structures. this makes these molecules isomers. using the three models and structural formulas, describe what it means to be an isomer in your own words. the structural arrangement of c, h, and o in glucose, fructose, and galactose differs. this helps explain why different model shapes are used for each monosaccharide.

Explanation:

Step1: Answer question 5

The molecular formula of glucose is $C_6H_{12}O_6$, fructose is $C_6H_{12}O_6$ and galactose is $C_6H_{12}O_6$. Each molecule has 6 carbon atoms.

Step2: Answer question 6

The molecular formulas for glucose, fructose and galactose are all $C_6H_{12}O_6$, so the ratio of C:H:O is 6:12:6 = 1:2:1 for all three.

Step3: Answer question 7

In water, the ratio of hydrogen to oxygen is 2:1. In glucose, fructose and galactose, the ratio of hydrogen to oxygen is also 2:1. Each sugar has 12 hydrogen atoms and 6 oxygen atoms.

Step4: Answer question 8

Isomers are molecules with the same molecular formula but different structural arrangements. Glucose, fructose and galactose have the same molecular formula ($C_6H_{12}O_6$) but different structural arrangements of carbon, hydrogen and oxygen atoms. Glucose has an aldehyde - group in its open - chain form and a six - membered ring in its cyclic form. Fructose has a ketone - group in its open - chain form and a five - membered ring in its cyclic form. Galactose has a different spatial arrangement of hydroxyl groups compared to glucose in its cyclic form.

Answer:

1. 6 carbon atoms in each molecule.
2. C:H:O ratio is 1:2:1 for glucose, fructose and galactose.
3. The ratio of hydrogen to oxygen in each sugar is 2:1, same as in water.
4. Isomers are molecules with same molecular formula but different structural arrangements. Glucose, fructose and galactose are isomers as they have $C_6H_{12}O_6$ but different structures.