biofinal

Biology II Final Review Sheet 

Term 1- Infectious diseases



  1. Koch’s postulates: Koch's postulates are four criteria designed to establish a causal relationship between a microbe and a disease.

Koch’s 4 Postulates:
1. Presence: The microorganism must be found in abundance in all organisms suffering from the disease but should not be found in healthy organisms.

2. Isolation & Culture: The microorganism must be isolated from a diseased organism and grown in pure culture.

3. Reproduction & Disease: The cultured microorganism should cause disease when introduced into a healthy organism.

4. Re-isolation: The microorganism must be re-isolated from the experimentally infected host and identified as being identical to the original specific causative agent.



  1. Pathogen vs. microbe:


Pathogen: A pathogen is a living thing that causes disease. Viruses and bacteria can be pathogens, but there are also other types of pathogens. Every single living thing, even bacteria themselves, can get infected with a pathogen.

Microbe: Microbes that cause disease are called pathogens. It is important to remember that: A pathogen is a microorganism that has the potential to cause disease. 

An infection is the invasion and multiplication of pathogenic microbes in an individual or population/A microscopic organism, which can be pathogenic or non-pathogenic. Pathogenic microbes cause disease.



  1. Disease vs. infectious disease:


Infectious Disease: These are diseases caused by pathogenic microorganisms, such as bacteria, viruses, parasites, or fungi. These diseases can spread, directly or indirectly, from one person to another. Examples include influenza, HIV/AIDS, and tuberculosis.

(Non-Infectious) Disease: These diseases are not caused by infectious agents. They include chronic diseases like heart disease, diabetes, and most cancers, which are often caused by genetic factors, lifestyle choices, and environmental factors.

  1. Viruses

    1. structure and reproduction: 

Structure: Viruses are composed of genetic material (DNA or RNA) enclosed in a protein coat called a capsid; some viruses also have an outer lipid envelope derived from the host cell membrane.

Reproduction: Viruses replicate by infecting a host cell and hijacking the host's cellular machinery to produce viral components, which are then assembled into new viral particles.

  1. viral diseases: Illnesses caused by viruses, such as influenza, HIV, and COVID-19.

  2. vaccines: Biological preparations that provide immunity to a particular infectious disease, often by stimulating the immune system to recognize and fight the pathogen.

  3. advantages and adaptations:  Viruses can mutate rapidly, allowing them to evade the host immune system and develop resistance to antiviral drugs.

  4. naked vs. enveloped: 

Naked Viruses: Lack an outer lipid envelope and are generally more resistant to harsh environmental conditions.

Enveloped Viruses: Have an outer lipid envelope and are typically more sensitive to desiccation, heat, and detergents.

  1. retroviruses:  A type of virus that uses reverse transcription to integrate its RNA genome into the host DNA, such as HIV.

    1. HIV starts as RNA (through reverse transcriptase) → DNA goes against dogma

  2. antigenic shift vs. drift: 

Antigenic Shift: A major change in the antigenic composition of a virus due to the reassortment of its genome segments, leading to new virus strains. (ex. COVID-19)

Antigenic Drift: Minor changes in the virus's antigens due to mutations, resulting in variations of virus strains. (ex. rhinovirus)




  1. Bacteria 

    1. structure: Bacteria are prokaryotic cells with a simple structure, including a cell wall, cell membrane, cytoplasm, and sometimes a capsule. They lack a nucleus and membrane-bound organelles.

    2. replication:  Bacteria primarily reproduce asexually through binary fission, where a single bacterial cell divides into two identical daughter cells.

    3. toxins: Many bacteria produce toxins, which are harmful substances that can damage host tissues and cause disease. Examples include the botulinum toxin produced by Clostridium botulinum and the cholera toxin produced by Vibrio cholerae.

    4. antibiotics: Drugs that kill or inhibit the growth of bacteria. They target specific bacterial structures or processes, such as cell wall synthesis or protein synthesis.

    5. three things that cause disease

      1. pili (antigens?)

      2. toxin 

      3. capsule 

        1. gram positive/ negative

  2. Immune system

    1. external barriers to infection: Physical and chemical barriers that protect the body from pathogens, including the skin, mucous membranes, and antimicrobial substances like lysozyme in saliva.

    2. lines of defense: 

Innate Immunity: The non-specific first line of defense against pathogens, involving physical barriers, phagocytic cells, and inflammatory responses.

Adaptive Immunity: The specific second line of defense that involves the activation of lymphocytes (T cells and B cells) and the production of antibodies.

  1. clonal replication: The process by which immune cells (lymphocytes) proliferate and differentiate in response to a specific antigen, creating a large population of cells that can specifically target the pathogen.

  1. Correlation vs. causation (for ALL diseases!): 

Correlation: A relationship or connection between two variables where changes in one variable are associated with changes in another, but this does not imply that one causes the other.

Causation: A cause-and-effect relationship where one variable directly affects another, establishing that one event is the result of the occurrence of the other event.



Term 2 – Neurological disease

  1. Technology (brain)

  1.  PET scan: An imaging test that helps reveal how tissues and organs are functioning by detecting the radiation emitted by a radioactive tracer injected into the body.

  2. fMRI: Measures brain activity by detecting changes in blood flow, providing insights into brain function and identifying regions involved in specific tasks.

  3. MRI: Uses strong magnetic fields and radio waves to produce detailed images of the organs and tissues in the body, often used to diagnose brain and spinal cord conditions.

  4. EEG: Records the electrical activity of the brain using electrodes placed on the scalp, commonly used to diagnose epilepsy and other neurological disorders.



  1. Parts of the brain

  1. Senses (types and locations for processing!): Different senses are processed in specific regions of the brain. For example, the occipital lobe processes vision, the temporal lobe processes hearing, and the parietal lobe processes touch and spatial awareness.

  2. Lobes:

Frontal Lobe: Involved in decision-making, problem-solving, and planning.

Parietal Lobe: Processes sensory information and spatial orientation.

Temporal Lobe: Involved in hearing, memory, and language.

Occipital Lobe: Processes visual information.

Cerebellum: navigation, coordination & balance

  1. Broca and Wernicke’s area (function  and disorder): 

Broca’s Area: Located in the frontal lobe, responsible for speech production. Damage to this area can result in Broca's aphasia, characterized by difficulty in speech production.

Wernicke’s Area: Located in the temporal lobe, responsible for language comprehension. Damage to this area can result in Wernicke's aphasia, characterized by fluent but nonsensical speech and difficulty understanding language.

Conduction aphasia: lesions the pathway between the frontal and temporal lobe cause this aphasia; 



  1. Parts of a neuron

  1. diagram and function of nerve cell: Neurons consist of a cell body (soma), dendrites (receive signals), and an axon (transmits signals). The axon terminal releases neurotransmitters to communicate with other neurons.

  2. action potential and diagram: A rapid rise and fall in voltage across a neuron’s membrane that enables the transmission of nerve impulses. The process involves the movement of ions (sodium (depolar) and potassium (repolar)) across the membrane.

  3. synaptic transmission: The process by which neurotransmitters are released from the axon terminal of a neuron, cross the synaptic cleft, and bind to receptors on the dendrites of the next neuron, transmitting the signal.



  1. Pain and perception

  1.  excitatory (EPSP) vs. inhibitory neurons (IPSP): 

Excitatory Postsynaptic Potential (EPSP): A depolarizing event that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP): A hyperpolarizing event that makes a neuron less likely to fire an action potential.

  1.  pain circuit (synaptic connections): Neural pathways involved in the perception of pain, including sensory neurons, spinal cord processing, and brain regions responsible for pain perception.

  2. circuits for EPSPs/IPSPs*: 

Excitatory Postsynaptic Potentials (EPSPs):

Function: Depolarize the postsynaptic membrane, making it more likely to fire an action potential.

Mechanism: Excitatory neurotransmitters (e.g., glutamate) bind to receptors, opening ion channels that allow positively charged ions (e.g., Na+) to enter the cell.

Inhibitory Postsynaptic Potentials (IPSPs):

Function: Hyperpolarize the postsynaptic membrane, making it less likely to fire an action potential.

Mechanism: Inhibitory neurotransmitters (e.g., GABA) bind to receptors, opening ion channels that allow negatively charged ions (e.g., Cl-) to enter the cell or positively charged ions (e.g., K+) to exit.

  1. Sleep* 

    1. VLPO: Promotes sleep by inhibiting arousal systems in the brain.

    2. Arousal neurons: Neurons that keep the brain awake and alert, involved in the regulation of wakefulness.

    3. Orexin neurons: Neurons that produce orexin (hypocretin), a neuropeptide that regulates arousal, wakefulness, and appetite.

    4. SCN: The master clock of the brain that regulates circadian rhythms.

    5. Adenosine and caffeine: Adenosine promotes sleep by inhibiting neural activity; caffeine blocks adenosine receptors, promoting wakefulness.

    6. Narcolepsy: A sleep disorder characterized by excessive daytime sleepiness and sudden episodes of sleep.

    7. Types of sleep: Includes REM (rapid eye movement) sleep and non-REM sleep, each with distinct physiological and neurological characteristics.



  1. Drugs, addiction and neuronal changes

    1. reward pathway:  A series of brain structures involved in the experience of pleasure and reinforcement of behaviors.

    2. VTA: Produces dopamine, involved in reward and motivation.

    3. NAc: A key structure in the reward circuit, associated with pleasure and reinforcement.

    4. PFC: Involved in decision making, impulse control, and moderating social behavior.

    5. Tolerance and withdrawal: Tolerance refers to the need for increasing amounts of a drug to achieve the same effect, while withdrawal refers to the physical and psychological symptoms experienced when reducing or discontinuing the use of a drug.

  2. Epilepsy: A neurological disorder characterized by recurrent seizures due to abnormal electrical activity in the brain.



Term 3 - Metabolic diseases

  1. What is found in food?

  1. Calories: Units of energy provided by food 

  2. Macromolecules and subunits: Carbohydrates (sugars), proteins (amino acids), and fats (fatty acids).

  3. Additives, antibiotics: Substances added to food to preserve flavor or enhance taste and appearance; antibiotics may be used in livestock to prevent disease.

  4. Vitamins/minerals: Essential nutrients required in small amounts for various bodily functions.

  5. Fiber: Indigestible part of plant foods that aids digestion.

  6. GMO: Organisms whose genetic material has been altered using genetic engineering techniques.

  1. Human digestive system.

    1. organs, order and function: The digestive system includes the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Each organ plays a specific role in breaking down food, absorbing nutrients, and eliminating waste.

    2. enzymes involved: Enzymes such as amylase, protease, and lipase help break down carbohydrates, proteins, and fats, respectively.

    3. Pancreas (warehouse): -protease(proteins), amylase(carbs), lipase(lipids) and it goes to the small intestine

    4. Mouth: salivary amylase breaks down carbs in the mouth

    5. Stomach: pepsin breaks down proteins in the stomach
      -two types of neurons, send electrical signals (ghrelin/leptin)up to the brain (hypothalamus) 

    6. small intestine does most of the digestion and absorption of nutrients 


  2. Fasting vs. feasting 

    1. ring models (lipogenesis, lipolysis, gluconeogenesis): 

Lipogenesis: The process of converting excess glucose into fat for storage.

Lipolysis: The breakdown of fats into fatty acids for energy.

Gluconeogenesis: The production of glucose from noncarbohydrate sources during fasting.

  1. the liver is the master regulator: The liver regulates metabolism by controlling the storage and release of glucose and fats.

  1.  Appetite regulating hormones 

    1. ghrelin: A hormone that stimulates appetite.

    2. leptin: A hormone that suppresses appetite and regulates energy balance.

    3. role of the hypothalamus: The hypothalamus regulates hunger and satiety through signals from hormones like ghrelin and leptin.

  2. BMR/factors that impact it: BMR(Basal Metabolic Rate)-Age, sex, weight, body composition, and genetics.

  3. BMI/body composition: 

BMI: A measure of body fat based on height and weight.

BMR(baseline metabolic rate): how many calories do you burn by being alive 

Body Composition: The proportions of fat, muscle, and bone in the body.

  1. Diabetes: A metabolic disease characterized by high blood sugar levels due to insulin deficiency or resistance.

Type I: In diabetes type 1, the pancreas does not make insulin, because the body's immune system attacks the islet cells in the pancreas that make insulin.
Type II: In diabetes type 2, the pancreas makes less insulin than used to, and your body becomes resistant to insulin.

  1. Heart disease and atherosclerosis: Conditions involving the narrowing or blockage of blood vessels due to the buildup of plaques, leading to cardiovascular complications.

       

Term 4 – Cancer

  1. Cell Cycle (normal): The series of events that take place in a cell leading to its division and replication, including interphase, mitosis, and cytokinesis.

  2. Carcinogens

    - Hills vs. Koch’s postulates: Hill’s criteria are a set of nine principles to establish a causal relationship between a presumed cause and an observed effect; Koch's postulates are used to link a specific microorganism to a disease.

    - Ames test: A test to determine the mutagenic potential of a substance, indicating its carcinogenic potential.

  1. Abnormal Cell Cycle: Disruption in the normal regulation of the cell cycle, leading to uncontrolled cell division and cancer.

  • Transformation: The process by which normal cells become cancerous.

4. Malignant vs. Benign tumors: 

Malignant Tumors: Cancerous growths that can invade and destroy nearby tissue and spread to other parts of the body.

Benign Tumors: Non-cancerous growths that do not spread to other parts of the body.

5. Primary Site vs. Metastatic tumors

Primary Site: The original location where cancer begins.

Metastatic Tumors: Tumors that have spread from the primary site to other parts of the body.

6. Treatment

       - Radiation,  Surgery, and Chemotherapy:

Radiation: Uses high-energy particles or waves to destroy or damage cancer cells.

Surgery: Physical removal of cancerous tissue.

Chemotherapy: Uses drugs to kill or inhibit the growth of cancer cells.

7.  Stages of Cancer and the characteristics of the tumor:

Cancer stages range from I to IV, indicating the extent of cancer spread. Characteristics include tumor size, lymph node involvement, and metastasis.

8.  Mutations affect the cell cycle and carcinogens

- Hyper proliferation: Excessive cell division.

- Tumor Suppressor: Genes that normally prevent uncontrolled cell growth; mutations can lead to cancer.

      - Telomeres and telomerase: Telomeres protect chromosome ends; telomerase maintains telomeres, allowing cells to divide indefinitely.
-Over time, our chromosomes are at the edge(telomeres). As you copy your DNA it loses a little bit of DNA and reaches a point where no more DNA can be lost and the cell stops dividing or apoptosis.
-Telomerase helps regrow lost cells. If you can keep those chromosomes the right size, the cell continues to divide and stops aging, that's why cancer cells don't die/age because of those mutations.

9.  Odds ratio: A measure of association between an exposure and an outcome, indicating the odds of an outcome occurring with exposure compared to without exposure.
IF the odds ratio is above 1, more likely to get cancer, less than 1 less likely to get cancer (the number you get is the percentage of how much more likely you are to get cancer; 2.77x more likely __)

ED= exposed to disease

EH= exposed but healthy

NED= not exposed but diseased

NEH= not exposed and healthy



Other Notes:

  • aflatoxin-sometimes find in soybeans or other plants

  • casein-protein in diary

  • the types of protein you eat may nurture the tumor better. your diet may help the tumor grow depending on what you eat

  • diet can not only help promote weight loss or can increase/disease your rate of cardiovascular disease

  • whole foods plant-based diet can slow or reverse cardiovascular disease

  • our cells can get amino acids from breaking down proteins and metabolizing (non-essentials) you do not have to eat non-essential because you can make them yourself and manufacture those amino acids from carbs or lipids, there are some you can get from plants that your cells can't make.

  • even if there's a low percentage of proteins (potatoes) can give you a sufficient amount

  • plant base sources of proteins dont make cancer grow faster, but animal base sources of proteins do

  • food types don't cause cancer but can promote growth if mutations occur

  • eat items that are not processed that are more nutritious as a whole

  • If we have a virus, we are HIV positive, but the more and more the virus destroys T cells, once our T cells drop below a certain number, you have aids and aids is a syndrome/acquired immunodeficiency syndrome, caused by aggression and attack of HIV->on finals test?

  • cardiovascular blockages → probably have another blockage (erectile dysfunction) 

  • in a signaling cascade, transcription factors make cells go thru gene expression

  • mitochondria sends caspases to signal apoptosis

  • calcium lets neurotransmitters travel

Cell cycle (G1->S->G2->mitosis): The ordered sequence of events that a cell undergoes as it divides and duplicates itself, consisting of four main phases—G1 (gap 1), S (synthesis), G2 (gap 2), and mitosis.

G1-The cell grows and gets ready to copy its DNA.

Synthesis-DNA replication occurs, making an exact copy of the cell's genetic material. Duplicate chromosomes.

G2-The cell continues to grow and prepares for cell division. Prepares for mitosis

Mitosis-Mitosis, which includes prophase, metaphase, anaphase, and telophase, occurs after the G2 phase. It is the stage of the cell cycle where the replicated chromosomes are segregated and distributed equally into two daughter cells during cell division. Deals with the division of the nucleus.

Cytokinesis-The cell divides into two new cells, each with its own complete set of DNA. Cytokinesis completes the process by physically separating the cell into two distinct daughter cells, each with its own nucleus and cellular components.

Mitosis: A type of cell division where a parent cell divides into two daughter cells, each having the same number of chromosomes as the parent cell. Mitosis is essential for growth, repair, and asexual reproduction.

Cells spend most of their life here

Proto-oncogenes (oncogenes): Normal genes that regulate cell growth and division. When mutated or altered, they can become oncogenes, promoting uncontrolled cell growth and potentially leading to cancer, these are driver proteins(ONLY ONCOGENES ARE DRIVERS< NOT PROTO ONCOGENES)???

Everyone has proto-oncogenes that move the cells through stages of cell cycle-gas pedals (driver proteins) when driver proteins are made by taking a proto-oncogene DNA and make protogonen rna and ribosome makes dna into 

Driver plus cyclin = MPF when that signal is received the cell moves through that checkpoint (combined signal). Oncogenes are now corrupted signals when they’re mutated cells and will keep dividing until the proliferation (cells multiplying)

MPF-Maturation Promoting Factor (MPF) is a key regulatory complex involved in controlling the progression of the cell cycle, particularly the transition from the G2 phase to the M phase (mitosis).

Tumor suppressors: Genes that inhibit cell division and regulate cell growth, preventing the development of tumors. Mutations in tumor suppressor genes can contribute to cancer.

Drivers: Genetic alterations or mutations that promote cancer development by driving abnormal cell growth and proliferation.

Drivers are proto-oncogenes(Normal genes that regulate cell growth and division)

When cells acquire these driver mutations or alterations, they gain a growth advantage over normal cells. These changes disrupt the balance of cell growth and division, leading to the formation of tumors and the progression of cancer. These alterations essentially "drive" the abnormal behavior of cells, allowing them to proliferate( rapid increase or multiplication of cells. When cells proliferate, they undergo a process of division, resulting in the generation of new cell) unchecked and potentially invade surrounding tissues or spread to other parts of the body, causing harm and disease progression.



Checkpoints are tumor suppressors

cyclin/MPF: Cyclins are proteins that regulate the progression of the cell cycle. Maturation-promoting factor (MPF) is a complex of proteins, including cyclins and kinases, that triggers a cell's passage from the G2 phase into mitosis.

STPs: Series of molecular events within a cell that relay external signals to the cell's interior, leading to specific cellular responses.

Signal Transduction Pathway, which is a series of steps by which a signal from the outside of a cell is transmitted to the cell's interior. This pathway involves a cascade of molecular interactions that transmit the signal, leading to specific cellular responses.

Receptors: Proteins on the cell surface or within the cell that bind to signaling molecules, initiating a cellular response.

Signal (PDGF): Platelet-derived growth Factor (PDGF) is a signaling molecule involved in cell growth, division, and blood vessel formation.

PDGF stands for Platelet-Derived Growth Factor. It's a protein that plays a significant role in cell growth and division, particularly in the context of wound healing, embryonic development, and the formation of blood vessels.



PDGF is released by platelets (a type of blood cell) and various other cells in the body. It acts as a signaling molecule, binding to specific receptors on the surface of cells. When PDGF binds to its receptors, it triggers a cascade of signals inside the cells, leading to processes like cell proliferation, migration, and the stimulation of other growth factors.

Transduction proteins (TP): Proteins involved in transmitting signals from receptors to various cellular components.

Growth signals (growth factors) are proteins that tell cells to divide (undergo mitosis)



They use a process called signal transduction-Signal transduction is like a messaging system inside cells. It's how cells communicate and respond to signals from their environment or other cells. Imagine it as a chain reaction where a signal starts outside the cell, travels inside, and triggers a series of actions that help the cell respond and adapt to its surroundings. This process allows cells to react to changes, make decisions, and carry out various functions essential for life.



Transcription factor (TF): Proteins that control the process of transcription, regulating gene expression by binding to specific DNA sequences., someone said it was like a checkpoint? Not a checkpoint . Bro the girl i asked about this is yapping and i feel like it’s rude to ask mr spezzano now



Transcription factors transcribe genes that encourage growth (drivers, microtubules).

Transcription factors activate gene transcription

Transcription factors (note: they are molecules that need to bind to a gene, for it to be used to make a protein!




Apoptosis: Programmed cell death, crucial for maintaining tissue homeostasis, removing damaged cells, and preventing the proliferation of abnormal cells.

Results from external or internal signals (like DNA damage).



Cells shrink.



No inflammation or tissue damage because phagocytes eat cell debris. 




Necrosis: Uncontrolled cell death often results from injury or disease, leading to cell swelling and inflammation.

Results from tissue injury or infection



Cell swells and bursts



Causes inflammation then tissue damage



P53: A tumor suppressor gene that is critical in preventing cancer by regulating cell division and initiating apoptosis in damaged cells.



p53 is a tumor suppressor protein that plays a crucial role in preventing cancer development. Normally, p53 functions to regulate cell division, repair damaged DNA, and induce apoptosis (programmed cell death) in cells with irreparable DNA damage. This helps prevent the propagation of cells with mutations that could potentially lead to cancer.



However, mutations or inactivation of the p53 gene can disrupt its tumor-suppressing functions. When p53 is not functioning properly, cells can accumulate genetic errors more easily, as damaged cells might continue to divide instead of undergoing apoptosis or repair. This can increase the likelihood of cells becoming cancerous and contribute to the development and progression of certain types of cancer.



Apoptosis, or programmed cell death, is helpful because it:

Removes old or damaged cells, keeping tissues healthy.

Helps the immune system by getting rid of infected cells.

Prevents cancer by eliminating potentially harmful cells.

Shapes organs during development.

Gets rid of cells with irreparable DNA damage, maintaining genetic stability.

Hyperproliferation + tumors: Excessive cell division leads to an increased number of cells, potentially forming a tumor or mass of abnormal cells.

Uncontrolled growth is called hyperproliferation.

This is what leads to cancer!

Can occur when CeLL receives too much pro-growth (divide) signals or when Cell ignores anti-growth (don’t divide) signals

Without signals:

DNA Damage

-Occurs randomly

-Caused by carcinogens

Which mutations cause cells to hyperproliferative?

Any mutation in a pathway that leads to: 

Overactive driver proteins (oncogenes).

Inactive tumor suppressors.

Angiogenesis: The process of forming new blood vessels, often associated with tumor growth and development.

Growth of new blood vessels

  • Signals that promote blood vessel growth also promote lymph vessel growth

Metastasis: The spread of cancer cells from the primary site to other parts of the body, forming secondary tumors.

Cancer cells migrate through lymph or blood

Cancer metastasis is like wound healing

“Fertile soil”: Term used metaphorically to describe the microenvironment that supports and enables the growth and spread of cancer cells.

Cell line: A population of cells derived from a single cell or group of cells and cultured in a laboratory.

Differentiation:  Differentiation is the process where cells become specialized for specific functions.

Dedifferentiation: Dedifferentiation is the reverse process, where specialized cells revert to a less specialized state. = high grade 

As tumor cells de-differentiate they become invasive 

A cells higher stage = less specialized in certain organs and more general for most organs 



Grade: Refers to the level of abnormality or aggressiveness of cancer cells, often indicating how quickly the cancer is likely to grow and spread.

Grade defines how invasive a tumor is likely to be.

A three step signaling chain reaction:

1. The PDGF receptor activates a

transduction protein - TP

2. The TP activates (changes the shape of) a 

Transcription factor - TF (EX: P53)

3. The TF passes into the nucleus

Steps in metastasis:we

Proliferation: Cells multiplying rapidly, creating more cells.

Local Invasion: Cells moving from where they originated to nearby tissues.

Growth of New Blood Vessels: Formation of new blood vessels to supply nutrients and oxygen to growing tissue.

Entering the Bloodstream: Cells getting into the blood vessels.

Exiting the Bloodstream and Forming a Secondary Tumor: Cells leaving the bloodstream and establishing a new tumor in a different part of the body.



Apoptosis and necrosis?

The difference between apoptosis and necrosis is in apoptosis, the affected cell actively participates in the cell death process, whereas in necrosis the cell death occurs in response to adverse conditions in the cell's environment. I think heat and radiation initiate apoptosis

Apoptosis

implodes->little damage

Programmed death, neighboring cells can send signals to other cells to die

Necrosis

explodes->lots damage

Necrosis is often considered unregulated/unprogrammed because it's a form of cell death that occurs due to external factors or extreme conditions, rather than a controlled, programmed process like apoptosis.

Angiogenesis and metastasis?

Angiogenesis vs proliferation

Proliferation: Means cells multiplying/cell division and increasing in number.

Angiogenesis: Is the creation/growth of new blood vessels to provide oxygen and nutrients to 



Tumor grade vs stage

"Grade" in biology denotes varying levels of structural or functional complexity within a group of organisms, while "stage" refers to specific points or phases in an organism's developmental sequence.

Grade - how different or unique they look, how many cells (proliferation)->related to growth, 

  • Grade describes how different cancer cells are from normal cells

  • Grade is about how invasive a cell is relative to healthy 

Stage - how likely they are to travel to the bloodstream / its ability to metastasize, if it spreads, the tumor itself (grown), metastasis->become a tumor --- MIGRATION, how much the tumor spread (beyond stroma and basement membrane)( stage 4 = spread to other organs)

Cancer stage - how much the tumor has spread

Stage describes how far the cells have migrated



Types of genes:

Oncogene-mutated gene

P53-regulates apoptosis



If the tumor cells are growing into stroma, it could be getting more problematic. If that spreads in the area you can have a high-grade tumor



3 common stereotypical stages of STP

  1. Reception of Signals

  2. Molecules that carry the messages across (transduction). Transduction proteins make up transduction

  3. Response (apoptosis, cell division, cells not dividing (inhibition), releases water)

Reason response is activated because of transduction proteins. Transduction proteins are activated because of their shape. The receptor changes its shape and doesn’t change its shape unless it's signaled to.

Ex: (lock that you can put key in is active because it has right shape)

  1. Reception of Signals: Cells receive signals from external factors, such as hormones, growth factors (Think of a growth factor as a signal that tells cells to grow, multiply, or do specific jobs in the body. It's like a message that guides cells on what they need to do to keep things working and growing well.), or environmental cues. These signals are detected by specific receptors on the cell's surface.

  2. Transduction: Once the signal is received, it triggers a series of molecular events inside the cell. Transduction involves the relay of the signal through a cascade of molecules, often including transduction proteins, which transmit the signal from the cell's surface to the nucleus or other cellular components.

  3. Cellular Response: The signal transmitted through the transduction pathway leads to a cellular response. This response can vary widely, including processes like apoptosis (programmed cell death), cell division (proliferation), inhibition of cell division, or changes in cell function, such as releasing water or altering metabolism.




Other:

Resonance: the vibration in an MRI that shows tissue (vibrates at a different frequency)

Biopsy: Looks for mutated genes in the blood (biopsy) or live tissue 

Mutated genes might be……..

  • Oncogenes (mutated proto-oncogenes)

  • P53 (regulates apoptosis)



What is intravasation?

 Intravasation is when cancer cells enter blood or lymphatic vessels.