Apicomplexan Parasites

Question 1

Giardia belongs to which phylum?

Answer 1

Metamonida

Question 2

Characteristics of Apicomplexa?

Answer 2

• Pellicle which determines the crescent shape
• Apicoplast= a non-photosynthetic plastid
• Apical complex
• Gliding motility
• Sexual and asexual reproduction

Question 3

What is the pellicle made up of?

Answer 3

The plasma membrane, the inner membrane complex, subpellicular microtubles and alveolin network

Question 4

What is the IMC made up of?

Answer 4

Inner and outer membrane

Question 5

What links the IMC to the subpellicular microtubules?

Answer 5

Network of alveolins

Question 6

What is the apical complex?

Answer 6

A group of cytoskeletal structures (conoid, apical ring, pre-conoidal ring) and membrane bounded organelles which include: rhoptries (club shaped), micronemes…

Question 7

What are the two secretory organelles found in the apical complex?

Answer 7

Rhoptries and micronemes

Question 8

Which stage of the Plasmodium parasite lacks rhoptries?

Answer 8

Ookinete

Question 9

Apical complex is involved in?

Answer 9

Gliding motility, cell attachment, cell invasion

Question 10

What genomes are there in Apicomplexa?

Answer 10

Nuclear genome
Mitochondrial gene
Apicoplast genome

Question 11

The apicoplast genome is how large?

Answer 11

35kb

Question 12

Shape of the apicoplast genome?

Answer 12

Circular

Question 13

What are the 4 major species of Plasmodium that can infect humans?

Answer 13

Malariae, ovale, vivax and falciparum

Question 14

What are the motile stages of Plasmodium infection?

Answer 14

Ookinete

Sporozoite

Question 15

What is the non-motile stage of Plasmodium infection?

Answer 15

Merozoite

Question 16

What is the motile stage of Toxoplasma infection?

Answer 16

Tachyzoite

Question 17

Male microgametocyte must undergo?

Answer 17

3 rounds of division to produce 8 microgametes which are released from the RBC in a process known as exflagellation

Question 18

How many of the human population are infected with Toxoplasma?

Answer 18

An estimated 1/3 of the global population

Question 19

Toxoplasma definitive host?

Answer 19

Members of felidae

Question 20

Sporulation of Toxoplasma occurs?

Answer 20

In the environment

Question 21

Only the sporulated cysts are?

Answer 21

Infectious

Question 22

Tachyzoites are involved in what type of infection?

Answer 22

Acute infection

Question 23

Bradyzoites are involved in what type of infection?

Answer 23

Chronic infection

Question 24

Toxoplasma infection of cats is?

Answer 24

Gut limited

Question 25

What is the main cause of death in HIV patients?

Answer 25

Toxoplasmosis

Question 26

Micronemes are involved in?

Answer 26

Gliding motility and cell entry

Question 27

Rhoptries are involved in?

Answer 27

Cell entry

Question 28

Subpellicular microtubules determine the trajectory of the Apicomplexan parasites which is?

Answer 28

The left handed spiral arrangement of the subpellicular microtubules results in a clockwise corkscrew trajectory

Question 29

What is the apicoplast?

Answer 29

A plastid which is present in the majority of Apicomplexan members It is a non-photosynthetic plastid

Question 30

What is the function of the apicoplast?

Answer 30

Involved in many anabolic pathways including biosynthesis of fatty acids, isoprenoids, iron-sulfur clusters and heme

Question 31

Apicoplast is surrounded by how many membranes?

Answer 31

4 membranes

Question 32

What do proteins that are transported to the apicoplast possess?

Answer 32

Bipartite targeting sequence N terminus Signal peptide Transit peptide

Question 33

What does the signal peptide do?

Answer 33

Targets the protein for the secretory pathway | The signal peptide is cleaved in the ER to reveal the transit peptide

Question 34

What does the transit peptide do?

Answer 34

Causes transportation of the protein through the multiple membranes of the apicoplast where it is then cleaved to reveal the mature protein

Question 35

What phenomenon is witnessed upon apicoplast destruction?

Answer 35

Delayed death phenomenon. Upon destruction of the apicoplast the parasite does not die straight away, it is unable to infect cells subsequently

Question 36

Transcription and translation machinery in the apicoplast is of what origin?

Answer 36

Prokaryotic origin

Question 37

Fluoroquinolone action?

Answer 37

Prevent DNA replication by inhibiting DNA gyrase or topoisomerase IV

Question 38

Rifampin action?

Answer 38

Prevents transcription by inhibiting DNA dependent RNA polymerase

Question 39

Fatty acids are assembled how many carbon atoms at a time?

Answer 39

Two carbon atoms at a time

Question 40

What synthesises fatty acids?

Answer 40

Fatty acid synthase

Question 41

How many fatty acid synthesis pathways are there?

Answer 41

Two

Question 42

What is the fatty acid synthesis pathway in vertebrates?

Answer 42

Type I pathway

Question 43

What is the fatty acid synthesis pathway in prokaryotes?

Answer 43

Type II pathway

Question 44

Fatty acid synthase of the type I pathway?

Answer 44

A large multifunctional polypeptide

Question 45

Fatty acid synthase of the type II pathway?

Answer 45

Made up of individual enzymes- distinct individual proteins. Each protein catalyses a single step in the reaction pathway.

Question 46

Isoprenoid biosynthesis in vertebrates is?

Answer 46

Mevalonate dependent

Question 47

Isoprenoid biosynthesis in parasites is?

Answer 47

Mavalonate independent... DOXP pathway

Question 48

Artemisinin is derived from?

Answer 48

Sweet wormwood

Question 49

Artemisinin was discovered by?

Answer 49

Tu YouYou a Chinese scientist