Unit 2 Biomolecules, Cell Structure and Cell Transport
True/False
Indicate whether the statement is true or false.
____1.The plasma membrane of cells is a selectively permeable membrane.
____2.The breakdown of the glucose molecule and other nutrients provides the energy to make ATP molecules.
____3.The cell membrane is composed of one layer of protein and one layer of carbohydrate.
____4.Osmosis pertains only to the movement of carbon dioxide molecules.
____5.All cells are surrounded by a cell membrane, which is called the nucleus.
____6.Lysosomes are small bodies in the cytoplasm that contain powerful digestive enzymes that enhance the breakdown of cellular components.
____7.Ribosomes are the sites of protein synthesis.
____8.It is through the membrane that materials enter and exit the cell.
____9.The mitochondria are the powerhouses of the cell.
____10.The Golgi body or apparatus is a collection of flat sac-like cisternae that look like a stack of pancakes; they act as storage warehouses of the cell.
____11.Every DNA molecule is a double-helical chain of nucleotides.
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____12.A chemical fuel that allows the body cells to do work and to function is known as ____.
a. / ATP / c. / H20b. / DNA / d. / RNA
____13.The more common of the two functions of carbohydrates is ____.
a. / dissolving fats / c. / energy storageb. / strengthening muscles / d. / insulating the body
____14.An enzyme that increases the rate of a chemical reaction without being affected by the reaction is known as a(n) ____.
a. / catalyst / c. / nucleotideb. / antagonist / d. / pyrimidine
____15.The building blocks of proteins are ____.
a. / carbohydrates / c. / amino acidsb. / hydrogen / d. / fatty acids
____16.A solution in which the salt concentration inside the cell is higher than outside the cell is known as ____.
a. / hypertonic / c. / isotonicb. / hypotonic / d. / base
____17.A solution in which the salt concentration is greater outside the cell than inside the cell is known as ____.
a. / hypertonic / c. / isotonicb. / hypotonic / d. / base
____18.A solution in which the salt concentration outside a cell is the same as that inside the cell is known as ____.
a. / hypertonic / c. / isotonicb. / hypotonic / d. / base
____19.____ transport is the transportation of materials against a concentration gradient.
a. / Diffusive / c. / pHb. / Osmotic / d. / Active
____20.The basic unit of biological organization of the human body is the ____.
a. / cell / c. / ribosomeb. / cytoplasm / d. / vacuole
____21.The control center of the cell is the ____.
a. / centriole / c. / nucleusb. / vacuole / d. / Golgi body
____22.The structure within the cell that is the site of ribosomal synthesis is the ____.
a. / nucleolus / c. / vacuoleb. / Golgi body / d. / centriole
____23.The site of protein synthesis is in the ____.
a. / ribosomes / c. / endoplasmic reticulumb. / lysosomes / d. / cilia
____24.The hereditary material of the cell is ____.
a. / mRNA / c. / DNAb. / tRNA / d. / mDna
Completion
Complete each statement.
25.Carbohydrates have two important functions: structural strengthening of the cell and ______.
26.______is the movement of water molecules through a semipermeable membrane from an area of high concentration of water molecules to an area of low concentration of water molecules.
27.______is the genetic material of a cell located in the nucleus of the cell.
28. One function of the carbohydrate macromolecule is to store energy. Which
other macromolecule also functions in
storing energy?
F DNA
G protein
H RNA
J lipid
29. Many land plants store energy in starch.
When energy is needed, the starch
molecules can be broken down quickly. This
chemical reaction produces which of the
following?
Aamino acids
B lipids
C monosaccharides
D RNA chains
30. Which of the following macromolecules is a
prominent part of animal tissue that
functions in insulation, helping animals
conserve heat?
F carbohydrates
G lipids
H proteins
J nucleic acids
31. Large biological molecules are made up of smaller subunits. What are these smaller
subunits called?
F enzymes
G polymers
H monomers
J cells
32. Which of the following is arranged in the
order of INCREASING levels of organization?
Aatom, molecule, cell
B molecule, atom, cell
C cell, atom, molecule
D cell, molecule, atom
33. Which of the following is a graphical depiction of an example of active transport taking place?
34. Explain the process illustrated in the diagram.
F passage of water molecules through a semipermeablemembrane to equalize concentration
G movement of molecules against a concentration gradient expending energy
H separation of suspended particles from a fluid environment through a porous membrane
J transport of molecules across a membrane from a high to low concentration gradient by
means of a carrier molecule