Exam 2 Flashcards
1
Q
Which of the following is a type of somatic cell?
A
Hepatocyte
2
Q
Cytoplasm is also known as _____fluid
A
Intracellular
3
Q
Blood plasma is classified as an_____ fluid
A
Extracellular
4
Q
How are the phospholipids arranged to form the plasma membrane?
A
Double layer with hydrophobic tails facing inward toward each other
5
Q
Which of the following best describes proteins that transport substances across the cell membrane?
A
Integral proteins
6
Q
Membrane proteins that function to label cells as normal or abnormal as well as “nametags” for cells are…
A
Recognition proteins
7
Q
Insulin is a hormone that binds to a molecule on the cell membrane and “ gives permission” for the cell to take up glucose. What kind of membrane protein does insulin bind to?
A
Receptor protein
8
Q
Folds of the plasma membrane that increase surface area are called
A
Microvilli
9
Q
What protein are microtubules composed of?
A
Tubulin
10
Q
Microtubules and microfilaments are the primary components of the
A
Cytoskeleton
11
Q
Which of the following is an example of an intermediate filament?
A
Collagen
12
Q
Which of the following organ systems have some organs containing ciliated cells?
A
Respiratory system
13
Q
What process involves the destruction of the cell by lysosomes?
A
Autolysis
14
Q
Membrane enclosed organelles containing oxidative enzymes that form hydrogen peroxide are known as…
A
Peroxisomes
15
Q
The folded inner membranes of mitochondria are called
A
Cristae
16
Q
The organelle that acts as enzymes for protein synthesis is the
A
Ribosome
17
Q
Cells actively involved in secreting proteins would contain large numbers or quantities of
A
Rough endoplasmic reticulum
18
Q
What organelle functions to chemically modified Cellular Products and package them in vesicles?
A
Golgi apparatus
19
Q
Ribosomes are produced here
A
Nucleolus
20
Q
Liver cells that produce a lot of glycogen probably have large concentrations of this organelle:
A
Smooth endoplasmic reticulum
21
Q
The genetic instructions for producing proteins ultimately come from…
A
DNA
22
Q
Which of the following enzymes is responsible for the production of messenger RNA (mRNA)?
A
RNA polymerase
23
Q
The functional units of DNA, which hold the instructions for the production of a single protein, are…
A
Genes
24
Q
The beginning of a gene is marked by a series of nucleotides called a…
A
Promoter sequence
25
On a gene, this series of nucleotides carries the actual code for a protein.
Coding strand
26
RNA polymerase makes a complementary copy of this series of nucleotides during transcription.
Template strand
27
Pre-mRNA (un-edited mRNA) contains non-coding regions called
Introns
28
The process whereby a complementary mRNA molecule is produced from a DNA template is called...
Transcription
29
The plasma membrane separates the ______from the______
Extracellular fluid; cytoplasm
30
A sequence of three nucleotides on a gene represents the code for...
One amino acid
31
Once transcription is completed, a sequence of three nucleotides on the mRNA molecule is called this:
Codon
32
How does mRNA get out of the nucleus?
Passes through nuclear pores
33
The first codon used during the synthesis of all proteins is...
AUG
34
______has the function of bringing amino acids to the ribosome during translation.
tRNA
35
During translation,______is synthesized in the_______.
A protein: cytoplasm
36
Which of the following contains the anti-codon used during translation?
tRNA
37
If the coding strand of a gene included the following nucleotides: ACTGCC...what nucleotide sequence would the corresponding mRNA molecule be composed of?
ACUGCC
38
A gene that is 90 nucleotides long would yield a protein that has this many amino acids:
30
39
If a protein is composed of 60 amino acids, how many codons (excluding the STOP codon) will make up the mRNA molecule transcribed from the gene for this protein?
60
40
A solution consists of a ______which dissolves the_______.
Solvent, solute
41
Movement of lipid soluble molecules across a cell membrane from an area of high concentration to one of low concentration occurs via....
Simple diffusion
42
Which of the following is able to freely and passively penetrate the plasma membrane?
O2
43
Molecules tend to move spontaneously______ their chemical gradient because of________.
Down : Kinetic energy from electrons
44
Diffusion will continue to occur…
Until the concentration gradient disappears and equilibrium is reached
45
The rate of diffusion is influenced by
All of the choices are correct
| The size concentration gradient. The size of the diffusing molecules. Membrane permeability
46
What will possibly happen to a red blood cell if placed into a hypotonic solution?
It will swell
47
In order for osmosis to occur, all of the following conditions have to exist EXCEPT...
There must be a minimum of two different molecules other than water in the solute
48
Which of the following is true regarding osmosis?
Water flows from an area of high water concentration to one of lower water concentration.
49
In facilitated diffusion, _______
A molecule is moved with its concentration gradient with the assistance of a carrier protein, and no energy is required.
50
When the movement of glucose into the cell by way of facilitated diffusion accidentally brings Na+ into the cell, energy must be expended to move the Na+ back out of the cell. This is an example of....
Secondary active transport
51
When we use the terms isotonic, hypotonic, and hypertonic to describe a solution, we are referring to the:
Solute concentration
52
Let's say you put a cell into solution 'A' and the cell bursts. Then you put another cell with the exact same solute concentration into solution 'B' and it swells, but it doesn't burst. What does this tell you about the two solutions?
Both solutions are hypotonic to the cells, and solution 'A' is hypotonic to solution 'B'
53
Cells placed in hypotonic solutions will...
Gain water from the solution
54
The concentration of an anion inside a cell is 3%. The concentration of this anion outside the cell is 1%. If needed, how could the cell obtain more of this ion inside the cell?
Active transport
55
Ion channels that can be opened by some kind of physiological stimulus are said to be..
Gated
56
Active transport
Utilizes energy.
57
The Na+/K+ pump transports______into the cell and _____ out of the cell per cycle.
2 K+ , 3 Na+
58
White blood cells are an important component of our immune system. One thing they do is consume and destroy bacteria by extending their plasma membrane around the bacterium and bringing it inside the cell in a vesicle and then digesting it. By what process do the engulf the bacterium?
Phagocytosis
59
Phagosomes often fuse with the membrane of which of the following organelles to be digested?
Lysosome
60
This characteristic of a cell is a reflection of the unequal distribution of cations and anions across the plasma membrane.
Transmembrane potential
61
Comparing intracellular to extracellular fluid, the intracellular fluid has a _____charge relative to the outside of a cell due to the presence of more ______in that solution.
Negative : anions
62
The cellular process responsible for cell division of somatic cells is known as:
Mitosis
63
Two sister chromatids attached by a centromere represent:
One chromosome
64
During the cell cycle, DNA is replicated during the_____ stage of______.
S, interphase
65
What does the enzyme DNA-helicase do?
It facilitates the unwinding of DNA for the purposes of replication and transcription.
66
How many pairs of sister chromatids occur in a human cell that is in prophase?
46 pairs
67
What are the spindle fibers that are used to control chromosome movement during mitosis composed of?
Microtubules
68
Centrioles move to opposite poles of the cell during...
Prophase
69
Chromosomes are lined up at the equator of the cell during this stage of mitosis:
Metaphase
70
Sister chromatids are pulled to opposite poles of the cell during...
Anaphase
71
During this mitotic stage, nuclear membranes re-form around the DNA, nucleoli reappear, and the cytoplasm continues to divide and separate into two cells.
Telophase
72
Benign tumors differ from malignant tumors in this way:
They do not metastasize
73
What happens to a cell when tumor-suppressor genes mutate?
The cell divides out of control and forms a tumor.
74
Without an activated Cyclin D protein…
The cell cannot transition from the G1 to the S stage of interphase
75
Tumor suppressor genes code for the production of proteins that…
Inhibit activation of cyclin- dependent kinases
76
Cellular apoptosis is achieved by the bursting of these organelles within the cell:
Lysosomes
77
Loss of DNA sequences at the ends of chromosomes in the_____ region may cause cell senescence.
Telomere
78
Cancer cells can most likely divide indefinitely due to the activity of an enzyme called...
Telomerase
79
The part of the neuron that initially receives either sensory information or motor commands is the:
Dendrite
80
The thick, proximal region of the axon is known as this:
Axon hillock
81
The myelin sheaths of the CNS neurons are produced by...
oligodendrocytes
82
The gap of exposed axon in the myelin sheath is the...
Nose of Ranvier
83
Which of the following cells would have the greater electrical attraction for sodium ions to enter the cell?
Cell with a membrane potential = -90mV
84
The membrane potential at which the electrical force equals the chemical force acting in opposite directions for a specific ion and its concentration gradient is known as that ions...
Equilibrium potential
85
Let's assume that a cell has a membrane potential of -70 mV. Assuming the concentration gradients for each of these ions are equal, which would have a greater magnitude of force to try to enter the cell?
Ca2+
86
The membrane of resting nerve cells is more permeable to_______ions than ______ions.
Potassium, sodium
87
Which of the following correctly describes the distribution of sodium and potassium ions in a neuron?
There are more sodium ions outside the cell and more potassium ions inside the cell
88
Ion channels to open or close in response to a change in membrane potential are called
Voltage-gated channels
89
What type of ion channels open or close in response to a neurotransmitter binding to its receptor?
Chemical-gated channels
90
Which of the following best describes the characteristics of the sodium and potassium channels that exist on the axons of neurons?
Sodium channels are gated while potassium channels can be either gated or leaky
91
The opening of sodium channels causes a rapid______ of sodium that ______the neuron's membrane.
Influx : depolarizes
92
Blocking_____ channels would prevent neuronal depolarization.
Na+
93
The minimum depolarization value needed to open the Na+ gates is called the…
Threshold
94
Which of the following is responsible for repolarization?
Outward diffusion of K+
95
If the resting membrane potential of a nerve cell is -70 mV, which of the following would represent the membrane potential of that same cell in a depolarized state?
-10mV
96
Which of the following would result in the hyperpolarization of a neuron?
A stimulus that resulted in the Efflux of K1+ ions
97
Which of the following changes in membrane potential is considered excitatory?
Depolarization only
98
Every time an action potential occurs, the membrane potential changes from -70 mV to +30 mV. Which of the following occurs at +30 mV and prevents the membrane potential from getting any more positive?
Both 'a' and 'b' are correct
a-The voltage-regulated sodium inactivation gates close
b-The voltage-regulated potassium gates open
99
The hyperpolarization of a nerve cell:
Decreases the chances for an action potential to occur by increasing the distance between the membrane potential and the threshold value
100
Conduction of an action potential in a myelinated axon is called_____ and is _____than in an unmyelinated neuron.
Saltatory propagation, faster
101
Chemicals that stimulate action potentials in postsynaptic cells are called...
Neurotransmitters
102
The influx of calcium into the axon terminal of a chemical synapse is responsible for the______.
Fusion of vesicles to the membrane and the exocytosis of neurotransmitter molecules
103
A neurotransmitter can be considered excitatory if it______ a muscle, gland, or another neuron.
Depolarizes
104
An action potential is accomplished by…
A positive feedback mechanism
105
After an action potential has occurred and acetylcholine has been released, acetylcholine is decomposed into acetate and choline by______ which are then reabsorbed by the______ to re-form acetylcholine.
Acetylcholinesterase, pre-synaptic membrane
106
Synaptic vesicles store______.
Neurotransmitter
107
After an action potential, the neuron uses sodium-potassium exchange pumps to restore the proper balance of sodium and potassium ion concentrations on both sides of the membrane. This is accomplished via…
Active transport
108
Neurotransmitter release would be inhibited by...
Blocking Ca2+ influx in the axon terminal
109
Acetylcholine usually induces an excitatory postsynaptic potential when binding to_______ receptors and an inhibitory postsynaptic potential when binding to some______receptors.
Nicotinic, muscarinic
110
When a neurotransmitter cannot recycle fast enough to keep up with the constant stimuli, a neuron can experience this:
Synaptic fatigue
111
This hormone also functions as a neurotransmitter and is important in the formation of memories.
Norepinephrine
112
This neurotransmitter works synergistically with acetylcholine to allow for smooth muscle contraction and movement.
Dopamine
113
SSRI's such as Zoloft and Luvox prevent reuptake enzymes from removing this neurotransmitter out of the synaptic cleft.
Serotonin
114
Which of the following drugs can cause paralysis by blocking postsynaptic receptor sites?
Curare
115
Which neurotransmitter is a structural mimic of LSD and is displaced when LSD is present… Thus resulting in hallucinations and other distortions of reality.
Serotonin
116
Which of the following drugs inhibit or reduces postsynaptic activity by blocking Na+ channels?
Novocain
117
Which of the following drugs works by "decreasing the distance" between the threshold value and the resting membrane potential?
Caffeine
118
All of the following prevent cholinergic synaptic activity except:
Caffeine
119
Botulinum toxin functions by...
Inhibiting the release of acetylcholine
