Download Chapter 2 and 3 Homework Assignment

BSC 103 Homework Chapters 2-3
Class # ____________
Fill in the missing information about macromolucles. (1-9)
Macromolecule
Subunits
One Function
One Example
Carbohydrate
3.
Storage
4.
2.
5.
Proteins
1.
Fatty acids and
glycerol
6.
7.
Enzymes
8.
Nucleotides
9.
DNA
Multiple Choice. Choose the letter that best answers the question or completes the statement.
____10. The joining of two smaller molecules to make a macromolecule involves the removal of
A. carbon
B. water
C. carbon dioxide
D. protein
____11. For an atom to achieve maximum stability and become chemically un-reactive, what must occur?
A. Its outermost energy shell must be filled with electrons
B. The number of electrons must equal the number of protons
C. Sharing of electron pairs is necessary
D. It must give away 2 electrons
____12. If two atoms have the same atomic number but different mass numbers, they are called
_______ of the same element.
A. isotopes
B. isomers
C. ions
D. orbitals
____ 13. Phospholipids make up a large part of cell membranes. They form a bilayer because
A. they have both proteins and lipids attached to them
B. they have two carbon rings instead of only one
C. they have only ionic bonds
D. they have both a hydrophobic (tail) and a hydrophilic (head) region
____14. The high surface tension of water is due to attraction between molecules of water called
A. adhesion
B. cohesion
C. tension
D. filtration
Select the type of chemical bond described in the statements below. (15-18)
A. nonpolar covalent bond B. polar covalent bond C. ionic bond D. hydrogen bond
____ 15. Results from a transfer of electron(s) between atoms
____ 16. Results from an equal sharing of electrons between atoms
____ 17. Best explains the attraction of water molecules to each other
____ 18. Best explains the bond between the oxygen and hydrogens in a single molecule of water
____19. Small groupings of atoms on a carbon backbone that help to determine physical and chemical properties
A. isomers
B. functional groups
C. organic molecules
D. proteins
____20. The plasma membrane allows the passage of some molecules while prohibiting the passage of others.
Thus the membrane is said to be
A. permeable
B. semi or selectively permeable
C. porous
D. semiporous
____21. Proteins in the plasma membrane are responsible for all of the following membrane functions EXCEPT
A. transport of molecules across membrane
B. response to the environment
C. adhesion of adjacent cells
D. maintaining fluidity at low temperatures
____22. A solution with a pH of 1 is ________ while a solution with a pH of 14 is ______.
A. Neutral ………..acidic
B. Acidic …………basic
C. Basic ………….neutral
D. Basic ………….acidic
____23. If a protein unfolds and loses its characteristic shape it is said to be
A. denatured
B. stable
C. functional
D. active
____24. The pH scale is used to measure the concentration of _______ in a solution.
A. Cl- ions
B. Na+ ions
C. H+ ions
D. All of the above
____25. Membrane components that provide a “fingerprint” are an essential part of membrane structure because
A. they help the immune system distinguish “self” from “non-self”
B. they help insure membrane fluidity at cold temps and stability at warm temps
C. they provide a mechanism for adjacent cells to attach firmly and form into tissues
D. provide an attachment point for chemical signals like the hormone adrenaline
Select the type of transport described in the statements below. (22-26)
A. Simple Diffusion B. Facilitated diffusion C. Osmosis D. Active transport
E. Endocytosis
____26. The movement of small molecules across a membrane to regions in which they are more
concentrated, using the energy in the form of ATP.
____27. The passive movement of small hydrophobic molecules from area of high concentration to area of
low concentration right through the lipid bilayer
____28. The movement of water across a membrane from area of low solute concentration to area of high
solute concentration
____29. The passive movement of solutes from area of high concentration to area of low concentration
through membrane transport proteins
____30. The active movement of large solids or fluids into cells enclosed within a vesicle