MCQs BIOCHEMISTRY: Carbohydrates, Proteins, Lipids and Nucleic Acids

1. What element forms the skeleton of organic molecules?
a. hydrogen atoms
b. phosphate atoms
c. carbon atoms
d. water molecules
2. How many bonds can carbon atoms form?
a. two
b. four
c. one
d. three
3. What happens in a dehydration reaction?
a. molecules are broken apart
b. monomers are bonded together and a water molecule is released
c. atoms are joined
d. it depends on what molecule it is
4. What reactions break apart polymers?
a. hydrolysis reactions
b. dehydration reactions
c. neutralization reactions
d. catalytic reactions
5. What is the general formula for carbohydrates?
a. (CH2O)n
b. (C2HO)n
c. (CHCHCH)
d. (COOH)
6. In what category of organic molecules are sugars placed?
a. proteins
b. lipids
c. hormones
d. carbohydrates
7. What are long chains of sugars called?
a. monosaccharides
b. disaccharides
c. polysaccharides
d. proteins
8. What is the most common monosaccharide?
a. cellulose
b. glucose
c. triglycerides
d. starches
9. Plants store energy as __________.
a. starch
b. lactose
c. RNA
d. protein
10. Muscle cells store energy in the form of ____________.
a. starch
b. glycogen
c. cellulose
d. steroids
11. Plant cell walls contain large amounts, of what polysaccharide?
a. carbon
b. water
c. chitin
d. cellulose
12. What type of organic molecule is a fat?
a. carbohydrate
b. lipid
c. starch
d. protein
13. What type of bonds found between carbon atoms cause fats to form kinks?
a. ionic
b. polar
c. double
d. proton
14. Fats and oils are composed of what two groups of molecules?
a. starch and sugar
b. glucose and fructose
c. fatty acids and glycerol
d. water and cellulose
15. What best describes phospholipid molecules?
a. their chemical formula is (CH2O)n
b. they form cell membranes
c. they are proteins
d. they are ionic
16. What structures are found in steroid molecules?
a. molecular rings
b. proteins
c. waxes
d. double helixes
17. What monomers make up proteins?
a. starches
b. enzymes
c. nucleic acids
d. amino acids
18. How many different amino acids are there?
a. ten
b. twenty
c. four
d. hundreds
19. What are the bonds between amino acids called?
a. hydrogen bonds
b. peptide bonds
c. ionic bonds
d. covalent bonds
20. Where do substrates attach to an enzyme?
a. peptide bond
b. ring binding site
c. active site
d. enzymatic site
21. Which of the following types of molecules is found in genetic material?
a. cellulose
b. enzymes
c. lipids
d. nucleic acids
22. Which of the following are found in nucleotides of DNA and RNA respectively?
a. deoxyribose and ribose
b. proteins and enzymes
c. fats and oils
d. sugars and starches
23. What are the four bases in DNA?
a. first, second, third and fourth
b. adenine, guanine, cytosine, uracil
c. nitrogen, hydrogen, carbon and phosphate
d. adenine, guanine, cytosine, thymine
24. Which of the following molecules function as an intracellular message carriers?
a. cAMP or cyclic adenosine monophosphate
b. enzymes
c. glycogen
d. water
25. What is the function of ATP, adenosine triphosphate?
a. message carrier
b. store and transport energy
c. make proteins
d. breakdown sugars

ANSWERS
1. c
2. b
3. b
4. a
5. a
6. d
7. c
8. b
9. a
10. b
11. d
12. b
13. c
14. c
15. b
16. a
17. d
18. b
19. b
20. c
21. d
22. a
23. d
24. a
25. b