Biochemistry of respiration
Teacher Resource 1 – Answers
1. What is the general formula of a carbohydrate?
Cx(H2O)y
2. Carbohydrates are classified into three groups. Name these and give brief descriptions
of the features of each group.
Monosaccharides, disaccharides and polysaccharides.
See http://thebiologyprimer.com/carbohydrates/ for more detail.
3. How are the largest carbohydrates made from the smallest? Show this process
diagrammatically.
For diagram see http://thebiologyprimer.com/carbohydrates/
4. Draw the α ring form of glucose.
For diagram see http://encyclopedia2.thefreedictionary.com/D-glucose
5. Show how a triglyceride lipid forms from its constituents. Name the bonds involved.
Glycerol plus three fatty acids joined by ester bonds. A suitable diagram can be
found at http://www.ib.bioninja.com.au/standard-level/topic-3-chemicals-of-life/32carbohydrates-lipids-and.html
6. Compare carbohydrates, fats and proteins in terms of their energy content.
This gives details of the energy content of each nutrient and highlights the
differences in the types of nutrients and how quick the energy is supplied from
each food type. http://www.msdmanuals.com/en-gb/home/disorders-ofnutrition/overview-of-nutrition/carbohydrates-proteins-and-fats
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7. In what units is the energy content of food measured? How is the energy value of a
food measured?
A standard table showing energy values in kilojoules and explaining the link to the
terms kilocalorie and Calorie can be found here:
http://www.ecoculturevillage.org/healthhappinesslongevity/calories-kilocalories-orkcals .The energy value of foods is measured in a bomb calorimeter.
8. How are the molecules NAD and FAD classified?
As dinucleotides. See colour-coded diagram of NAD in reduced and oxidised
forms at http://cnx.org/contents/185cbf87-c72e-48f5-b51ef14f21b5eabd@9.66:34/Biology
9. What is meant by the term co-enzyme?
A non-protein molecule that is necessary for an enzyme to catalyse its reaction.
E.g. NAD, FAD, coenzyme A and most important of all, ATP, without which
endothermic enzyme-catalysed reactions would not occur. See
http://sandwalk.blogspot.ie/2008/09/atp-is-coenzyme.html
10. Define the terms oxidation and reduction. What three chemical events can be called
oxidation?
See http://www.chemguide.co.uk/inorganic/redox/definitions.html for a simple
guide to the three ways of understanding oxidation: gain of oxygen, loss of
hydrogen and loss of electrons, and the converse for reduction.
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