Biochemistry - Cell Cycle, Apoptosis, and Cancer

c. Regulation of growth and division

Which of the following is a characteristic of cancer cells?

a. Limited ability to divide and replicate

b. Strict adherence to surrounding cell

c. Regulation of growth and division

d. Programmed cell death in response to damage

a. Inherited genetic mutations

What is the primary cause of cancer development?

a. Inherited genetic mutations

b. Exposure to environmental toxins

c. Viral infections

d. Random chance events

b. Eliminating damaged or unwanted cells

What is the role of apoptosis in normal and malignant cells?

a. Preventing autoimmunity and chronic inflammation

b. Eliminating damaged or unwanted cells

c. Promoting cell growth and division

d. Inhibiting angiogenesis and epithelial-mesenchymal transitions

a. Source of the signal that initiates apoptosis

What is the main difference between the extrinsic and intrinsic pathways of apoptosis?

a. Source of the signal that initiates apoptosis

b. Activation of caspase-3

c. Involvement of growth factors or hormones

d. Formation of new blood vessels

a. Genes that regulate cell growth and division

What are oncogenes and tumor suppressor genes?

a. Genes that regulate cell growth and division

b. Genes that promote apoptosis

c. Genes that control the extrinsic pathway of apoptosis

d. Genes involved in DNA repair

G1 Phase

The phase of cell growth and preparation for DNA synthesis.

Cyclin-CDK Complex

A key regulatory mechanism of the cell cycle progression.

M Phase

The mitotic phase where the cell divides into two daughter cells.

S Phase

Phase in which DNA replication occurs.

Checkpoint

Ensures DNA is undamaged before cell cycle progression.

True

T/F: The cell cycle is made up of G1, S, G2, and M phases.

False

T/F: CDKs activate cyclins to drive the cell cycle.

True

T/F: Cell cycle regulation prevents uncontrolled growth.

False

T/F: DNA replication occurs during the G2 phase.

True

T/F: Mutations in TP53 can impair cell cycle checkpoint control.

Apoptosis

Programmed cell death to eliminate damaged or unwanted cells.

Cancer

Uncontrolled cell growth due to cell cycle dysregulation.

Oncogene

Gene that promotes cell proliferation when mutated.

Tumor Suppressor Gene

Gene that inhibits cell division and promotes apoptosis.

BRCA1/2

Tumor suppressor genes involved in breast and ovarian cancer.

True

T/F: Apoptosis helps maintain tissue homeostasis.

False

T/F: Oncogenes slow down cell division.

True

T/F: Cancer can result from mutated tumor suppressor genes.

False

T/F: BRCA1 is located on chromosome 13.

False

T/F: Apoptosis only occurs in malignant cells.

Checkpoint Gene Mutation

Can disable cell cycle "brakes."

TP53 Mutation

Leads to accumulation of damaged cells.

Uncontrolled Progression

Caused by failed checkpoint response.

Genetic Instability

Result of continued division despite DNA damage.

Therapeutic Target

Checkpoints are potential drug targets.

True

T/F: Checkpoint abnormalities allow damaged cells to divide.

False

T/F: Functional checkpoints accelerate the cell cycle.

True

T/F: TP53 mutation can contribute to tumorigenesis.

False

T/F: Damaged DNA always halts cell cycle progression.

False

T/F: Checkpoint proteins are never considered in cancer therapies.

Anticancer Drugs

Target rapidly dividing cells in the cycle.

Treatment Goal

Disrupt cell division or trigger apoptosis.

Combination Therapy

Targets multiple stages for effectiveness.

Therapy Limitation

Effectiveness varies by cancer type/stage.

Drug Mechanism

Inhibits specific cell cycle phases.

False

T/F: All cancer treatments are equally effective for all cancers.

True

T/F: Cell cycle-targeting drugs induce apoptosis.

False

T/F: Chemotherapy only affects cancer cells.

True

T/F: Combination therapies improve treatment outcomes.

True

T/F: Cell-cycle drugs prevent DNA synthesis and mitosis.

Initiation

First step where mutation occurs.

Promotion

Proliferation of mutated cells via stimuli.

Progression

Acquisition of further mutations, tumor formation.

Metastasis

Spread of cancer to distant organs.

Familial Cancer Syndrome

Higher familial incidence of cancer.

False

T/F: Initiation involves multiple mutations.

True

T/F: Promotion is a reversible step.

False

T/F: Metastasis means local tumor growth.

True

T/F: Familial cancer syndrome can involve lifestyle factors.

False

T/F: Progression does not affect tumor aggressiveness.

Caspase-3

Common executor of apoptosis.

Extrinsic Pathway

Triggered by death receptors (e.g., Fas).

Intrinsic Pathway

Triggered by DNA damage, via mitochondria.

Bcl-2 Proteins

Regulate mitochondrial pathway.

p53

Activates intrinsic apoptosis in response to DNA damage.

False

T/F: Intrinsic pathway involves death receptors.

True

T/F: Caspase-8 is part of the extrinsic pathway.

True

T/F: Apoptosis contributes to tissue remodeling.

True

T/F: Both apoptosis pathways converge on caspase-3.

False

T/F: Bcl-2 family proteins are involved in the extrinsic pathway.