7a- detecting pathogens

Question 1

what does the immune system use to protect us from pathogenic agents?

Answer 1

antigens

Question 2

what is an antigen

Answer 2

a molecule that triggers an immune response to protect our body from pathogenic agents

Question 3

what are self antigens? (self markers)

Answer 3

self antigens are located on the surface of cells, and mark cells of an organism as ‘self’ so the immune system doesn’t attack them

Question 4

what are self antigens in the form of?

Answer 4

MHC markers (major histocompatibility markers)

Question 5

what are MHC class 1 markers?

Answer 5

a type of self antigen expressed on all nucleated cells in the body. Virtually all cells in human body have them except for those without a nucleus express MHC class 1 markers.

Question 6

what are MHC class 2 markers?

Answer 6

a type of self antigen found on specialised cells of the immune systems

Question 7

what are non-self antigens? (antigens)

Answer 7

non-self antigens are antigens immune system reads as ‘foreign’ or not belonging to that individual

Question 8

what happens if a non self antigen is recognised within the body?

Answer 8

the immune system is activated and attempts to eliminate it.

Question 9

what happens during a malfunction involving antigens, and what is it called

Answer 9

immune system results in an error such as recognition of self antigens as non-self, and it ultimately results in immune system attacking self-cells and is known as an autoimmune disease.

Question 10

what is a type of malfunction in the immune system?

Answer 10

Allergies are a type of malfunction involving an overreaction to allergens, a specific type of antigens.

Question 11

What are a few characteristics of allergens?

Answer 11

allergens are non pathogenic and harmless and immune system recognises them as foreign and mounts an unnecessary strong response, known as an allergic reaction

Question 12

what is an allergen?

Answer 12

an allergen is often a substance that initiates an allergic response by binding to antibodies that are already bound to receptors on mast cells. the response involves the release of histamine from mast cells, which causes an inflammatory response that can vary in severity.

Question 13

cellular pathogen?

Answer 13

have a cellular structure and are living organisms

Question 14

non cellular pathogens?

Answer 14

do not have a cellular structure and are non living

Question 15

why does a disease occur?

Answer 15

a disease occurs when pathogens disrupt normal cell functions

Question 16

what do pathogens produce, and what does it cause?

Answer 16

pathogens can produce toxins causing cell lysis, inhibit protein or nucleic acid synthesis, affect cellular respiration, preventing energy production.

Question 17

what are extracellular pathogens? example?

Answer 17

interfere with cell function from outside the cell (eg bacteria)

Question 18

what are intracellular pathogens? example?

Answer 18

disrupt function from within the cell (eg viruses)

Question 19

why are non pathogenic threats such as DNA mutations leading to cancer not considered pathogenic?

Answer 19

non pathogenic threats such as DNA mutations leading to cancer not considered pathogenic since they are errors in genetic code rather than agents causing disease

Question 20

what are some types of cellular pathogens?

Answer 20

bacteria, fungi, worms, protozoa (BFWP)

Question 21

what is bacteria and how does it reproduce?

Answer 21

unicellular prokaryotes, can infect nearly any part of the body. They cause disease by producing toxins and enzymes that disrupt cell function or lead to cell death. they reproduce asexually via binary fission.

Question 22

what is fungi and how does it reproduce?

Answer 22

Eukaryotic organisms that include yeasts and moulds and contain long, branching filaments called hyphae. Reproduces through both sexual and asexual reproduction via spore formation.

Question 23

what are worms and how do they reproduce?

Answer 23

Multicellular invertebrate parasites whose development include egg, larval and adult stages. They reproduce sexually via a complex life cycle

Question 24

what are protozoa and how do they reproduce?

Answer 24

single-celled eukaryotes, can be free-living or parasitic. can inhibit nucleic acid synthesis, protein synthesis, and different stages of cellular respiration. Reproduces both from sexual and asexual reproduction.

Question 25

what are some types of non- cellular pathogens?

Answer 25

viruses and prions

Question 26

what are viruses? How do they reproduce? How do they cause disease?

Answer 26

infectious agents composed of genetic material (DNA or RNA) inside a protein coat called a capsid, sometimes surrounded by a lipid envelope. Cannot reproduce independently and must insert their genetic material in a host cell to replicate. Cause disease by lysing cells during replication.

Question 27

What are prions?

Answer 27

Abnormally folded proteins that can induce nearby normal proteins to become misfolded. Occur in mammals and specifically affect brain and neural structures. Do not contain nucleic acids.