IAL L1

IAL Biology L1

21 flashcards · Biology · by Michael Katsikas

1. Why is water a polar molecule ?

   Because it has partial negative and positive charges.

2. With respect to water molecules, what is the difference between adhesion and cohesion ?

   The ability of water molecules to "stick" together is called cohesion. Adhesion is the ability of water molecules to "stick" to OTHER molecules (not water molecules).

3. What is the driving force that leads to water properties such as adhesion, cohesion and surface tension ?

   These properties are all a result of hydrogen bonding.

4. Which of the following effects can occur because of the high surface tension of water? a) Lakes cannot freeze solid in winter even with extremely low temperatures. b) A spider can walk across the surface of a small pond. c) Organisms can resist temperature changes, although they give off heat due to chemical reactions. d) Sweat can evaporate from the skin, helping to keep people from overheating.

   B.

5. Which of the following pair(s) is/are correctly matched? A. Phospholipid - Lecithin B. Oligosaccharide - b-glucose C. Protein - HAemoglobin D. All of the above

   D.

6. Which of the following does not represent an energy-rich compound? A. Carbohydrates and Proteins B. Proteins and Vitamins C. Only carbohydrates D. All of the above

   C. Proteins and vitamins are less energy-rich biomolecules.

7. Identify which of the following pairs is MISMATCHED: A. Monosaccharides - Carbohydrates B. Cholesterol - Protein C. DNA - Nucleic Acid D. Triglycerides - Lipids

   B.

8. Which monomers combine to form lactose?

   Glucose and Galactose

9. What do glucose and fructose have in common ?

   They have the same molecular formulas, the same structural formulas and they are isomers.

10. Name a polysaccharide with an a-glycosidic linkage.

    Cellulose

11. A covalent linkage (bond) between two monosaccharides is referred to as:

    Glycosidic bond

12. How does starch and chitin differ from each other?

    Starch is a polysaccharide of alpha glucose while chitin is a polymer of N-acetylglucosamine. Starch contains α(1→4) glycosidic bonds while chitin contains β(1 → 4) linkage. Chitins is a structural polysaccharide while starch is a storage polysaccharide.

13. Which two functional groups are always found in amino acids?

    Carboxyl and amino groups

14. The specific amino acid sequence in a protein is its: a) Primary structure. b) Secondary structure. c) Tertiary structure. d) Quaternary structure.

    A

15. Which of the following is true of protein structure? a) Peptide bonds are formed by hydrolysis. b) Peptide bonds join the amine group on one amino acid with the R group of another amino acid. c) Secondary protein structures are caused by hydrogen bonding between atoms of the peptide backbone. d) Tertiary protein structure emerges when there is more than one polypeptide in a protein.

    C

16. Name the three parts a nucleotide is comprised of.

    A nitrogenous base, a sugar and a phosphate group.

17. Ho does DNA and RNA differ ?

    DNA is double stranded, while RNA is single-stranded. RNA contains Uracil instead of Thymine. RNA contains a ribose sugar, while DNA a deoxy-ribose sugar. DNA holds the genetic material which is transferred to the next generation, while RNA is a copy of a PART of ONE of the DNA strands. RNA can exit the nucleus, while DNA cannot.

18. The base sequence of a short strand of DNA is 5′-CAACT-3′. Identify its complementary strand.

    3'-GTTGA-5'

19. How do phospholipids interact with water molecules?

    The polar heads interact with water; the nonpolar tails do not.

20. Choose the correct statement about biological waxes: a) They contain at least one steroid molecule. b) They are fatty acids bound to long chain alcohol molecules. c) They are extremely hydrophilic. d) They are made of 4 fused carbon ring molecules.

    B

21. Name some of the functions of membrane-associated proteins.

    Recognition, anchorage, transduction, transport, linkage, enzymes.