Bio Lec Exam 2 Flashcards
(157 cards)
1
FALSE
The inner membrane of mitochondria is folded into cristae. Chloroplasts have thylakoid membranes.
2
2) FALSE
All cells have a plasma membrane that
regulates the passage of molecules into and
out of the cell. Animal cells do not have a
cell wall.
3
3) TRUE
It is true that mitochondria are thought to be
derived from aerobic bacteria that became
part of the eukaryotic cell through
endosymbiosis.
4
4) TRUE
It is true that mitochondria and chloroplasts
are able to reproduce independently from the
division of the cell.
5
5) TRUE
It is true that receptor-mediated endocytosis
involves the use of specific proteins in the
cell membrane.
6
6) FALSE
It is true that the fluidity of a membrane
increases as the percentage of unsaturated
fatty acids in the phospholipids goes up. As
the percentage of unsaturated fatty acids
goes down, the membrane become less fluid
7
False
In the cells that line the lumen of the small
intestine, it is tight junctions, not gap
junctions that keep materials in the digestive
tract from slipping between the cells and
entering the tissues.
8
8) FALSE
In the sodium-potassium pump, sodium is
transported out of the cell and potassium is
transported into the cell using ATP energy.
9
9) FALSE
The process by which a white blood cell or
an amoeba engulfs bacteria is called
phagocytosis. Pinocytosis is “cell drinking”
and instead of solid particles, the cell
engulfs small droplets of liquid or very tiny
particles.
10
10) TRUE
It is true that an extracellular matrix helps
some cells to adhere to neighboring cells.
11
11) TRUE
If a change in pH alters an allosteric site
where an inhibitor binds, but doesn’t change
the active site for the intended substrate, it
would be possible for an enzymatically
controlled reaction to occur as normal. This
is a true statement.
12
12) TRUE
In order to roll a rock down a hillside, you
must first push it up the hill. It is true that
pushing the rock is analogous to the energy
of activation of a chemical reaction
13
True
Enzyme inhibition is the process that turns
off an early enzyme in a metabolic pathway.
This can occur when the product of the
pathway acts as an inhibitor. This is a true
statement.
14
14) FALSE
This is a false statement. Enzymes are
proteins that speed up chemical reactions.
15
15) [A, C, D]
Bacterial cells have a cell wall, a cell
membrane, and ribosomes (along with
cytosol) but do not have any membrane-
bound organelles such as a nucleus or a
Golgi apparatus.
16
16) [A, B, C]
Eukaryotic cells in general will not be
affected by penicillin. Animal cells do not
have a cell wall and plant cell walls are
constructed differently from bacterial cell
walls. It is also true that bacteria that have
already formed their cell walls would be
unaffected and that penicillin would stop the
growth of active colonies of susceptible
bacteria.
17
17) [A, B, C]
The bacteria cell wall is located outside the
cell membrane. There may or may not be
fimbriae present on the outside of the cell.
Inside the cell there may be plasmids and
DNA, but the DNA is not separated from the
rest of the cell by a membrane. The
glycocalyx, which has a protective function,
lies outside of the cell membrane
18
A, B, D
Microtubules are important for maintaining
cell shape, for moving chromosomes during
cell division and for moving materials across
the surface of respiratory cells. Microtubules
do not play a role in the breakdown of fatty
acids and lipids. That is accomplished by the
peroxisome.
19
19) [C, D, E]
Plant cells and prokaryotic cells have a cell
wall. Animal cells do not. The functions of
the cell wall are to shape, support, and
protect the cell.
20
20) [A, C]
21
21) [A, B, C, D]
The major functions of the plasma
membrane include everything but the
production of proteins used in construction
of the cell wall.
22
22) [A, D, E]
The extracellular matrix can help cells
adhere to neighboring cells, and can be
made of collagen and elastin. It influences
the activities of the cytoskeleton and,
therefore, the shape and activities of a cell.
23
23) [C, D, E]
The binding of a chemical messenger to a
membrane receptor usually initiates a
cascade of reactions called the signal
transduction pathway which can cause
changes in the shape or movement of a cell
or the activation of an enzyme. The
chemical messenger may also affect
activities in the nucleus. For example, it can
cause a gene to be activated.
24
24) [B, D, E]
Cyclic AMP and calcium ions are common
second messengers. Cyclic AMP usually
activates an enzyme in a second messenger
system. Second messenger systems usually
amplify the cellular response to a chemical
messenger.