p.29
Spindle Assembly Checkpoints
During which phase does the Spindle Assembly Checkpoint occur?
During early phases of Metaphase.
p.11
DNA Damage Checkpoints
In which phases of the cell cycle do DNA Damage Checkpoints operate?
From G1 to S and S to G2/M.
p.8
DNA Damage Checkpoints
What ensures that DNA replication was successful before proceeding?
Control mechanisms and checkpoints.
p.10
Mitogens and Signal Transduction
What role do mitogens play in cellular processes?
They are typically part of a signal transduction pathway.
p.9
Mitogens and Signal Transduction
What role do mitogens play in the cell cycle?
They instruct the cell to divide.
p.14
Cyclins and Cyclin-Dependent Kinases (Cdks)
What do Cyclin-dependent protein kinases (Cdks) do?
They phosphorylate target proteins, which can turn them on or off.
p.3
Regulatory Mechanisms of the Cell Cycle
What can lead to cells becoming cancerous?
Mutations in DNA that disrupt normal cell cycle regulation.
p.27
DNA Damage Checkpoints
What is the role of checkpoints in the cell cycle?
To ensure proper progression and prevent errors.
p.26
p53 and its Role in Cancer
How does a loss of function mutation in the p53 gene affect the progression of the cell cycle?
It would lead to increased progression of the cell cycle.
p.13
Cyclins and Cyclin-Dependent Kinases (Cdks)
What are Cyclins?
Proteins that regulate the cell cycle by activating Cdks.
p.29
Spindle Assembly Checkpoints
What is the role of Spindle Assembly Checkpoints?
They occur during early phases of Metaphase to ensure proper chromosome alignment.
p.31
Mitosis and Cytokinesis
What is the role of the centromere DNA sequence?
It promotes the assembly of a protein complex called the kinetochore.
p.9
Mitogens and Signal Transduction
What is the function of the gas pedal in the car analogy?
It represents the signal that prompts the car (cell) to move (divide).
p.10
Mitogens and Signal Transduction
What is the primary function of mitogens in cells?
To initiate signal transduction pathways that alter cell behavior.
p.32
Spindle Assembly Checkpoints
What role do 'naked' kinetochores play in the spindle assembly checkpoint?
They block the transition into anaphase.
p.30
Mitosis and Cytokinesis
What promotes the assembly of the kinetochore?
A centromere DNA sequence.
p.26
p53 and its Role in Cancer
What happens to p21 expression if there is a loss of function mutation in the p53 gene?
We would expect decreased expression of p21.
p.15
Cyclins and Cyclin-Dependent Kinases (Cdks)
Are CDKs normally active or inactive?
CDKs are normally present but inactive.
p.17
Regulatory Mechanisms of the Cell Cycle
What is the first step in the transition from G1 to S phase of the cell cycle?
Mitogen is produced extracellularly.
p.36
Regulatory Mechanisms of the Cell Cycle
What mechanisms can cause the cell cycle to pause?
Checkpoints that assess DNA integrity and cellular conditions.
What is the function of proto-oncogenes?
Their normal function is to promote the cell cycle.
p.34
Tumor Suppressor Genes
What is the role of p21?
It is a CDK inhibitor and functions as a Tumor Suppressor.
What are mitogens?
They are substances that promote cell division, acting as proto-oncogenes.
What type of mutations in proto-oncogenes are linked to cancer?
Gain of function (GOF) mutations.
p.27
Regulatory Mechanisms of the Cell Cycle
What monitors the transition from S phase to M phase?
Regulatory mechanisms and checkpoints.
p.20
Regulatory Mechanisms of the Cell Cycle
What is the role of active Rb in the cell cycle?
It inhibits the cell cycle until a cell is ready to divide.
p.15
Cyclins and Cyclin-Dependent Kinases (Cdks)
What is the role of CDKs in the cell cycle control system?
CDKs are activated to regulate the cell cycle.
p.15
Cyclins and Cyclin-Dependent Kinases (Cdks)
Do cyclins have enzymatic activity?
No, cyclins have no enzymatic activity.
p.13
Regulatory Mechanisms of the Cell Cycle
What happens if the regulation of the cell cycle is disrupted?
It can lead to uncontrolled cell division and cancer.
p.2
Regulatory Mechanisms of the Cell Cycle
What can cause the cell cycle to pause?
Regulatory mechanisms that respond to DNA damage or other cellular stress.
What is the purpose of the G2 phase in the Cell Cycle?
It is the second growth phase before mitosis.
p.33
Tumor Suppressor Genes
What is the function of the Rb protein?
It acts as a tumor suppressor by regulating the cell cycle.
p.13
Regulatory Mechanisms of the Cell Cycle
What regulates transitions of the cell cycle?
Cyclins and Cyclin-Dependent Kinases (Cdks).
p.14
Cyclins and Cyclin-Dependent Kinases (Cdks)
What do Cdks and Cyclins regulate?
Transitions of the cell cycle.
p.34
Tumor Suppressor Genes
What is the role of mutations in cell cycle proteins?
They are often linked to cancer.
p.7
Regulatory Mechanisms of the Cell Cycle
What is the nature of cell division?
It is a highly regulated process.
p.25
Tumor Suppressor Genes
Why is p53 significant in cancer biology?
It is one of the most commonly mutated genes in cancers.
p.5
Mitosis and Cytokinesis
What is the mitotic phase?
The phase where the cell divides into two daughter cells.
p.18
Regulatory Mechanisms of the Cell Cycle
What type of environment influences the decision to start the cell cycle?
Extracellular and cytosolic environments.
p.1
Cyclins and Cyclin-Dependent Kinases (Cdks)
What is the role of cyclins and cyclin-dependent kinases (Cdks) in the cell cycle?
They regulate the progression of the cell cycle, and their dysregulation can lead to cancer.
p.32
Spindle Assembly Checkpoints
What does the spindle assembly checkpoint ensure?
That all chromosomes are bound to microtubules.
p.9
Mitogens and Signal Transduction
What analogy is used to explain the cell cycle?
A parked car that is on but not moving.
p.11
DNA Damage Checkpoints
What analogy is used to explain how cells know when to stop dividing?
A car stopping at a stop sign for road work.
p.12
DNA Damage Checkpoints
What happens if DNA is damaged at the G1 → S checkpoint?
The cell cycle pauses until DNA is repaired.
p.15
Cyclins and Cyclin-Dependent Kinases (Cdks)
What do CDKs need for activation?
CDKs need cyclins and other factors for activation.
p.13
Cyclins and Cyclin-Dependent Kinases (Cdks)
What role do Cyclin-Dependent Kinases (Cdks) play in the cell cycle?
They are enzymes that, when activated by Cyclins, drive the cell cycle transitions.
p.2
Regulatory Mechanisms of the Cell Cycle
What initiates the cell cycle?
Regulatory mechanisms that signal the cell to begin division.
p.2
Tumor Suppressor Genes
What are tumor suppressor genes?
Genes that help regulate the cell cycle and prevent uncontrolled cell growth.
p.6
Mitosis and Cytokinesis
What is the M phase of the Cell Cycle responsible for?
Nuclear division (mitosis).
p.33
Tumor Suppressor Genes
What is the function of p21?
It is a CDK inhibitor that acts as a tumor suppressor.
What is the normal function of proto-oncogenes?
To promote the cell cycle.
p.5
Regulatory Mechanisms of the Cell Cycle
What can happen if a cell fails to pass a checkpoint?
The cell may undergo apoptosis or enter a resting state.
p.29
Mitosis and Cytokinesis
What are the main phases of Mitosis?
Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis.
p.32
Spindle Assembly Checkpoints
What happens if anaphase continues without microtubules attached to kinetochores?
It can lead to improper chromosome segregation.
p.12
DNA Damage Checkpoints
What is the purpose of the G1 → S checkpoint?
To ensure DNA is not damaged before entering the S phase.
p.31
Mitosis and Cytokinesis
What happens during metaphase?
Chromosomes attach to the mitotic spindle and begin to align.
Which type of cancer is associated with the deregulation of Cyclin D?
Various types, including breast cancer.
p.17
Regulatory Mechanisms of the Cell Cycle
What happens after mitogen is produced?
Mitogen binds to cell receptor.
What is the function of proto-oncogenes?
To promote the cell cycle.
What are the main phases of the cell cycle?
Interphase and the mitotic phase (M phase).
What is the role of Cyclin D in the cell cycle?
It promotes the cell cycle, making it a proto-oncogene.
p.5
Mitosis and Cytokinesis
What are the sub-phases of mitosis?
Prophase, metaphase, anaphase, and telophase.
How do mutations in proto-oncogenes contribute to cancer?
They can lead to increased cell division and growth, promoting tumor formation.
p.11
DNA Damage Checkpoints
What role do DNA Damage Checkpoints play in the cell cycle?
They act like breaks, pausing the cell cycle to repair DNA damage.
p.10
Mitogens and Signal Transduction
What are the three main steps in altered cell behavior due to mitogens?
1. Signal Reception 2. Transduction 3. Response.
p.8
Regulatory Mechanisms of the Cell Cycle
How does the cell determine when to start or block the cell cycle?
Through regulatory mechanisms and signaling pathways.
p.8
Tumor Suppressor Genes
What can happen if regulatory systems in the cell cycle fail?
It can lead to uncontrolled cell division and cancer.
p.33
Tumor Suppressor Genes
What is the role of tumor suppressor genes in the cell cycle?
Their normal function is to halt the cell cycle.
What occurs during interphase?
Cell growth, DNA replication, and preparation for mitosis.
p.4
Mitosis and Cytokinesis
What are the stages of mitosis?
Prophase, metaphase, anaphase, and telophase.
p.4
DNA Damage Checkpoints
What role do checkpoints play in the cell cycle?
They monitor and regulate the progression of the cell cycle.
p.5
Regulatory Mechanisms of the Cell Cycle
What role do checkpoints play in the cell cycle?
They ensure that the cell is ready to proceed to the next phase.
p.1
Mitogens and Signal Transduction
What is the function of mitogens in cancer genetics?
They are signaling molecules that stimulate cell division, which can contribute to cancer if dysregulated.
p.3
Tumor Suppressor Genes
What is a primary cause of cancer?
Increased cell divisions.
p.3
DNA Damage Checkpoints
How can environmental factors contribute to cancer?
Exposure to carcinogens can cause mutations that lead to cancer.
p.30
Mitosis and Cytokinesis
How many kinetochores are present per sister chromatid?
One kinetochore per sister chromatid.
What is interphase in the cell cycle?
Interphase consists of G1, S, and G2 phases.
What are the general principles of the cell cycle and mitosis?
The cell cycle consists of phases that lead to cell division, including interphase and mitosis.
p.12
DNA Damage Checkpoints
What happens if DNA is unsuccessfully replicated at the S → G2/M checkpoint?
The checkpoint becomes active and pauses the cell cycle until appropriate proteins are synthesized for M phase.
p.36
Tumor Suppressor Genes
What are tumor suppressor genes?
Genes that help regulate the cell cycle and prevent uncontrolled cell division.
What occurs during the S phase of the Cell Cycle?
DNA synthesis (replication).
p.7
DNA Damage Checkpoints
What is the effect of DNA damage checkpoints on the cell cycle?
DNA damage checkpoints block the cell cycle.
What is the cell cycle?
The series of phases that a cell goes through from its formation to division.
p.18
Regulatory Mechanisms of the Cell Cycle
What is the transition phase from G1 to S phase in the cell cycle?
The decision to start the cell cycle.
p.1
Spindle Assembly Checkpoints
What are spindle assembly checkpoints?
Mechanisms that ensure proper chromosome alignment and separation during cell division, preventing cancerous growth.
p.20
Regulatory Mechanisms of the Cell Cycle
What does the Cyclin D/Cdks complex phosphorylate?
The Rb protein (Retinoblastoma protein).
p.28
Regulatory Mechanisms of the Cell Cycle
What is the role of M Cyclin in the cell cycle?
It regulates the transition from G2 to M phase.
p.36
Regulatory Mechanisms of the Cell Cycle
What regulatory mechanisms initiate the cell cycle?
Regulatory proteins and checkpoints that ensure conditions are favorable for cell division.
p.17
Regulatory Mechanisms of the Cell Cycle
What is activated after mitogen binds to the receptor?
Signal Transduction is activated.
p.21
Regulatory Mechanisms of the Cell Cycle
Does phosphorylated Rb inhibit or promote the cell cycle?
It promotes the cell cycle.
p.24
p53 and its Role in Cancer
What happens to p53 in the absence of DNA damage?
It is targeted for destruction.
p.35
Spindle Assembly Checkpoints
Which checkpoint is associated with the spindle assembly?
Spindle assembly checkpoint.
p.35
Cyclins and Cyclin-Dependent Kinases (Cdks)
What is the role of Cyclin D in the cell cycle?
It promotes progression through the G1 phase.
p.30
Mitosis and Cytokinesis
What happens to the nuclear envelope during prophase?
It breaks down, involving lamins and other proteins.
p.11
DNA Damage Checkpoints
What happens to the cell cycle when DNA is damaged?
The cell cycle pauses to allow for DNA repair.
p.10
Mitogens and Signal Transduction
What environments are involved in the signal transduction pathway?
Extracellular environment and Cytosolic environment.
p.8
Cyclins and Cyclin-Dependent Kinases (Cdks)
What regulates the transition from G1 to S phase?
Cyclins and Cyclin-Dependent Kinases (Cdks).
p.21
Regulatory Mechanisms of the Cell Cycle
What is the role of the Rb protein in the cell cycle?
It is a target of an active cyclin D/Cdk complex.
What is the primary purpose of the cell cycle?
To ensure proper cell division and replication.
p.7
Mitogens and Signal Transduction
What role do mitogens play in the cell cycle?
Mitogens promote the cell cycle.
p.6
Mitosis and Cytokinesis
What are the stages of mitosis?
Prophase, Metaphase, Anaphase, Telophase.
p.4
Regulatory Mechanisms of the Cell Cycle
How does the cell cycle ensure genetic consistency?
By accurately replicating DNA before cell division.
p.18
Regulatory Mechanisms of the Cell Cycle
What are the three main steps in the process of Cyclin D transcription?
1. Signal Reception 2. Transduction 3. Response.
p.35
Regulatory Mechanisms of the Cell Cycle
What is the function of p21 in the cell cycle?
It inhibits cyclin-dependent kinases, thus halting the cell cycle.
p.12
DNA Damage Checkpoints
What is the function of the S → G2/M checkpoint?
To ensure that DNA has been successfully replicated without errors.
p.22
DNA Damage Checkpoints
What happens if a cell responds to a mitogen but has DNA damage?
The cell cycle will pause at a checkpoint to attempt to repair the DNA.
p.17
Regulatory Mechanisms of the Cell Cycle
What is the cell's response to activated signal transduction?
Transcription of Cyclin D.
What does the G0 phase indicate in the Cell Cycle?
The cell stays in G1 for very long periods of time.
p.4
Mitosis and Cytokinesis
What is mitosis?
The process of nuclear division that results in two daughter cells.
What are the main phases of the cell cycle?
Interphase and the mitotic phase (M phase).
p.35
p53 and its Role in Cancer
What is the role of p53 in the cell cycle?
It acts as a tumor suppressor and regulates the cell cycle.
p.19
Cyclins and Cyclin-Dependent Kinases (Cdks)
What is the function of the Cdk complex?
To phosphorylate target proteins, regulating the cell cycle.
p.22
Regulatory Mechanisms of the Cell Cycle
What is the role of Rb in the cell cycle?
Inactivating Rb prepares the cell for the transition from G1 to S phase (DNA replication).
p.22
DNA Damage Checkpoints
What is the primary function of a DNA damage checkpoint?
To pause the cell cycle and attempt to repair the DNA.
What are proto-oncogenes?
Genes that promote cell division and can lead to cancer when mutated.
p.6
Mitosis and Cytokinesis
What is cytokinesis?
Cell separation following mitosis.
p.35
Tumor Suppressor Genes
What type of mutations in tumor suppressor genes are linked to cancer?
Loss of function (LOF) mutations.
What are proto-oncogenes?
Normal genes that can become oncogenes due to mutations, leading to cancer.
p.35
Mitogens and Signal Transduction
What are mitogens?
Signals that promote cell division.
What are the general principles of the cell cycle?
The cell cycle consists of phases that lead to cell division, including interphase and mitosis.
What are proto-oncogenes?
Normal genes that can become oncogenes when mutated, leading to cancer.
p.2
Tumor Suppressor Genes
How are genes linked to cancer identified?
By determining their roles in the cell cycle as tumor suppressor genes or proto-oncogenes.
p.5
Mitosis and Cytokinesis
What is cytokinesis?
The process that follows mitosis, dividing the cytoplasm and organelles into two daughter cells.
p.18
Regulatory Mechanisms of the Cell Cycle
What is the outcome of Cyclin D translation?
It promotes the transition from G1 to S phase.
p.22
DNA Damage Checkpoints
What are the consequences of DNA damage in a cell?
1. Prevent DNA replication 2. Induce mutations 3. Cause chromosomal breaks.
p.36
Tumor Suppressor Genes
How are genes linked to cancer identified in the cell cycle?
By studying mutations in tumor suppressor genes and proto-oncogenes.
p.4
Mitosis and Cytokinesis
What is cytokinesis?
The division of the cytoplasm, resulting in two separate cells.
p.1
Tumor Suppressor Genes
What is cancer genetics?
The study of genetic mutations and alterations that lead to cancer.
p.18
Regulatory Mechanisms of the Cell Cycle
What role does a mitogen play in the cell cycle?
It signals the cell to start the cycle.
What occurs during interphase?
The cell grows, duplicates its DNA, and prepares for division.
p.1
Tumor Suppressor Genes
What role do tumor suppressor genes play in cancer?
They help regulate cell growth and division, preventing uncontrolled cell proliferation.
p.1
DNA Damage Checkpoints
How does DNA damage affect cancer development?
Unrepaired DNA damage can lead to mutations that contribute to cancer progression.
p.1
p53 and its Role in Cancer
What is the significance of the p53 gene in cancer?
It is a tumor suppressor gene that regulates the cell cycle and prevents genomic instability.
