Final Exam Flashcards
What are proteases a type of?
caspases
What is cellular senescence a feature of?
aging
What gene codes for the longevity protein?
SIRT1
How is senescence detrimental for cells?
Detrimental for aging
What gene mutation will lead to cancer?
Tumor suppressing genes
What becomes less efficient at generating ATP as we age?
Mitochondria
Dopamine, Glycine, and GABA are all examples of____ neurotransmitters?
A) Excitatory
B) Inhibitory
C) Complex
D) Doug Chidester “DA MITTINNN”
B) Inhibitory
What are the 3 types of drugs that affect the neuromuscular junction?
ACH - like action,
Acetylcholinesterase inhibitors,
ACH receptor antagonists
What types of cancer result from an overexpression Bcl-2?
Lymphoma, breast, Prostate, and lung cancer.
Do antioxidants increase lifespan?
no
What step in cancer development is the initial genetic insult?
Initiation
what type of signal is apoptosis initiation from mitochondria releasing cytochrome c?
Internal Signal
What type of drug affects the neuromuscular junction by decreasing the breakdown of ACH? (e.g. alzheimers, nerve gas)
Acetylcholinesterase inhibitors
Does dietary restriction decrease likelihood of cellular damage?
YES
What is the term that describes cells being replaced at the same rate as being lost?
Homeostasis.
What breaks up proteins to get a cell to apoptosis?
Caspases
Does protein degradation decrease with age?
yes
What are the normal genes that control cell growth and differentiation known as?
Protooncogenes
What protein can induce reactive oxygen species production?
p53
What is telomere attrition a feature of?
aging
How many muscle fibers does each motor nerve stimulate?
300,000
When a cell is injured or diseased, it will likely go through___, taking days and causing inflammation of the surround tissue.
A) Apoptosis.
B) Necrosis
C) Meiosis
D) Cytotermination
B) Necrosis
What is an autoimmune disease where antibodies attack ACH receptors at the neuromuscular junction resulting in an inability to transmit enough signals from nerves to muscles?
Myasthenia Gravis
What type of drug affects neuromuscular junction by not being destroyed by cholinesterases and keeping persistent action? (e.g. Nicotine)
ACH- like action
What can unregulated cell division lead to?
Cancer
Why can red wine lead to an increase in lifespan?
Resveratol in red wine can induce SIRT1
Does hematopoiesis increase with age?
NO
What is known as tumor necrosis factor receptor?
Death receptors that can initiate apoptosis
What are mutated proto-oncogenes known as?
Oncogenes
What type of cell death is due to injury or disease?
Necrosis
What step in cancer development is tumor cell invasion?
Metastasis
Is there a difference in the resting membrane potential of a nerve and muscle fiber?
NO
What is a typical numeric range for a resting potential?
-70 to -80 mV
As the cells of the body age one hallmark of the process is Genomic instability which refers to:
A) Shorter telomeres= increased mortality.
B) Accumulation of DNA damage throughout life.
C) Increase in likelihood of inflammation.
D) Cells being less efficient at generating ATP.
B) Accumulation of DNA damage throughout life.
What step in cancer development is tumor development?
Progression
Where is a muscle action potential transmitted along?
Transvers tubules
What are the 2 big theories of cancer?
Clonal evolution model,
Stem cell theory
According to stem cell theory of cancer, are cancer stems cells less likely to be resistant to drugs?
NO
How do epigenetic alterations contribute to aging?
decrease—>histone actylation
Increase—–>Heterochromatin = silencing of proliferation genes.
Why do the mouths of the ACH receptors have negatively charged amino acids?
Keeps out negative ions.
Allows mostly Na+ (small amounts K+ and Ca++) to diffuse through and create a positive charge known as the END plate potential.
Are senescent cells still metabolically active?
yes, just no more replication.
What controls cells growth?
Protooncogenes and tumor suppressor genes.
The release of what ion causes the stimulation of muscle contraction?
Ca++
During what type of cell death will a cell shrink in size?
Apoptosis
What step in cancer development is multiple mutations leading to an increased number of mutated cells?
Promotion
What are caspases’ major function?
apoptosis
Is there a difference in the velocity of conduction of a nerve and muscle fiber?
Yes, Nerve=FASTER
What gene controls unregulated progression through the cell cycle?
Tumor suppressing genes
In the Clonal evolution model theory of cancer, why does therapy require death or removal of all tumor cells?
Every mutated cell has potential to develop another tumor.
Does protein degradation increase with age?
NO
What type of cell produces high levels of inflammatory cytokines and matrix metalloproteinases (MMP’s)
Senescent cells
Caspases are a type of protease whose major function is apoptosis?
A)True
B)False
A) True
What does the end plate potential stimulate?
Contraction of a Muscle.
During what type of cell death is a cell engulfed by a macrophage?
Apoptosis
Which horns of the spinal cord do motor neurons originate from?
Anterior horns
Does SIRT1 regulate p53?
YES
Is risk of cancer in those carrying mutations much higher than those w/out the mutations?
YES
What type of disease occurs from defective apoptosis of autoreactive cells?
Autoimmune diseases such as rheumatoid arthritis, lupus, and type 1 diabetes.
Are skeletal muscle fibers innervated by large myelinated nerves?
YES
What type of drug affects the neuromuscular junction by binding to ACH receptors, so ACH cannot?
ACH-receptor antagonists
What term describes an increase in formation of ROS within the mitochondria, and may cause an adaptive reaction, which produces increased stress resistance and a long-term reduction of oxidative stress?
Mitohormesis
Serotonin is the primary neurotransmitter used in neuromuscular junctions at motor end plates?
A) True
B) False
B) False
What is deregulated nutrient sensing a feature of?
aging
What type of diseases enhance apoptosis of T-helper cells in patients?
Autoimmune diseases….HIV
When cells build up a resting membrane potential, there should be a high concentration of ____ outside the cell and a high concentration of ____ Inside the cell.
Na,
K
During acetylcholine secretion, where is the ACH finally released?
Synaptic space
Why do cell cycles decrease in stem cells in aged cells?
More DNA damage and overexpression of INK4A (Cyclin inhibitor)
What cell internalizes and degrades cells during apoptosis, preventing inflammation?
macrophage
Even though cellular senescence can independently occur from DNA damage, reactive oxygen species, telomere shortening, and oncogenes and tumor suppressor genes; What can influence the rest to act?
Reactive oxygen species
What are shorter telomeres associated with at a young age?
increased mortality at young age
What protein controls expression of genes for antioxidants?
p53
If the cancer gene being mutated is rare, is the individual at a lower risk of cancer?
NO
After the release of Ca++ that stimulates muscle contraction, what pumps Ca++ back in the myofibril?
Ca pumps in the Sarcoplasmic Reticulum
Which type of mutations mostly affect tumor suppressor genes?
inherited mutations
What state do cells tend to stay in?
homeostatic, proliferation, or cell death?
Homeostatic
During what type of cell death will a cell increase in size and lyse?
Necrosis
What nutrient sensing pathways enhance aging?
Anabolic pathways—-(Insulin, Insulin-like growth factor)
During acetylcholine secretion, what must initially reach the neuromuscular junction?
Nerve impulse
What is the most commonly mutated tumor suppressor gene?
TP53
What do caspases cleave, which in turn lead to apoptosis?
Cytoplasmic proteins
What contains a death domain that is important in external signaling of apoptosis initiation?
Ligands
According to stem cells theory of cancer, what should treatment focus on?
Eradication of small number of stem cells.
During what 2 steps of cancer development is there a recruitment of cells?
promotion, Progression.
Do senescent cells re-enter the growth cycle?
no
What is the advantage of having each impulse at the neuromuscular junction being 3 times as much as the end plate potential necessary to stimulate contraction?
Safety factor to Prevent repetitive discharge.
What type of disease occurs from mutations in apoptotic proteins?
Cancer
What type of drug must individuals with myasthenia gravis use every few hours in order to function?
acetylcholinesterase inhibitors
What proteins hide telomere damage from repair mechanisms, contributing to aging?
shelterin
During acetylcholine secretion, how many vesicles fuse with the terminal membrane?
125
What type of channels are found in ACH receptors?
Chemical gated ion channels:
-With small diameters and negatively charged amino acids at the mouth to keep negative ions out
How does a voltage change result in muscle contraction?
Voltage change triggers dihydropyridine receptors linked to Ca release channels to release Ca causing a contraction.
If the cancer gene being mutated is rare, is the individual at a higher risk of cancer?
Yes
What can accumulation of oncogenes lead to?
Deregulation of the Cell Cycle.
Eventually daughter cell will form tumor.
What do ligands, containing a “death domain” activate?
caspase 8 or 10
what is a loss of protein homeostasis a feature of?
aging
During acetylcholine secretion, a nerve impulse at the neuromuscular junction causes what channels to open and flux into the presynaptic terminal?
Ca Channels
Ca flows in.
In what type of diseases does Fas signaling not work?
Autoimmune diseases
Does hematopoiesis decrease with age?
YES
Is there a difference in the duration of action potential of a nerve and muscle fiber?
YES, MUSCLE=LONGER
According to stem cell theory of cancer, what percentage of all cells in the tumor have stem cell activity?
<1%
During acetylcholine secretion, what attracts the ACH vesicles to the membrane next to the dense bars?
Ca
Prokaryotes and Eukaryotes differ in all of these ways except:
A) Presence/absence of a nucleus.
B) Organization of DNA/RNA.
C) Presence/Absence of membrane-bound organelles.
D) Presence/Absence of ribosomes.
D) Presence/Absence of ribosomes.
What is found in synaptic space degrading ACH to acetyl-CoA and choline?
Acetylcholinesterase
What could be weakened and not reach threshold levels with some meds and toxin, such as botox, resulting in paralysis?
End Plate Potential
How is senescence beneficial for cells?
Beneficial for tumor suppression
What type of cell death is programmed and self induced?
Apoptosis
What signals nutrient scarcity and promotes cell survival and catabolism?
Sirtuins
In what type of cell death are the intracellular contents inflammatory?
Necrosis
How are cells lost in body?
Death, Sloughing off, or injury
Does dietary restriction increase likelihood of cellular damage?
no
What are the 4 causes of cellular senescence?
DNA damage
Telomere shortening
Reactive oxygen species
Oncongenes and tumor suppressor genes
What triggers apoptosome complex in the cytoplasm during apoptosis initiation?
Cytochrome C (from mitochondria)
What protein is important for tumor suppressing?
p53
What induces SIRT1 expression, thus not increasing lifespan?
over nutrition.
What part of the cell cycle are senescent cells in?
G-1
What is an altered intracellular communication a feature of?
aging
What is the biological significance of apoptosis during embryonic development?
Forming the digits of the hands and feet.
What is mitochondrial dysfunction a feature of?
aging
Are skeletal muscle fibers innervated by small unmyelinated nerves?
NO
In what type of cell death will mitochondria release cytochrome c?
Apoptosis
What leads to the production of reactive oxygen species?
mitochondrial dysfunction
What may be our body’s defense against stress by stimulating proliferative and survival signals?
Reactive oxygen species
What ion influx creates a positive potential charge at the postsynaptic muscle fiber known as the END Plate Potential?
Na+ Mostly
In a normal healthy nervous system, chemical synapses can only transmit a signal in one direction.
A) True
B) False
A) True
What is stem cell exhaustion a feature of?
aging
What type of signal is apoptosis initiation from ligands activating caspase 8 or 10?
External signal
what are epigenetic alterations a feature of?
aging
In what type of cell death will a cell’s plasma membrane bud off?
Apoptosis
What type of proteins are associated with a loss of stability due to the reduction of them in numbers as we age?
Chaperone proteins
What causes an altered intracellular communication and thus lead to aging?
increases in inflammation
What is genomic instability a feature of?
Aging
What are the 4 steps of cancer development?
1) Initiation
2) Promotion—-(Multiple mutations lead to increased # of mutated cells)
3) Progression—(Tumor development)
4) Metastasis——(Tumor cells invasion)
How does genomic instability contribute to aging?
Loss of DNA repair mechanisms = Aging acceleration
Damage to Nuclear Lamina = increases premature aging.
What does acetylcholinesterase degrade acetylcholine into?
Acetyl-CoA,
Choline
According to the stem cell theory of cancer, are cancer stem cells more likely to be resistant to drugs?
YES
Does excess reactive oxygen species increase aging?
no
Where is acetylcholinesterase found?
Synaptic cleft
Do eukaryotic cell indefinitely divide?
no
