1 / 86

Sub-topic (b) Responses to Infections

Biological Systems. Sub-topic (b) Responses to Infections. Learning Outcome. Describe the structure of viruses. Three types of microorganism. fungi. bacteria. viruses. Parasite. Viruses are true parasites living off the cell they have infected.

naasir
Télécharger la présentation

Sub-topic (b) Responses to Infections

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Biological Systems Sub-topic (b)Responses to Infections

  2. Learning Outcome • Describe the structure of viruses.

  3. Three types of microorganism fungi bacteria viruses

  4. Parasite • Viruses are true parasites living off the cell they have infected. • Some viruses enter a host and leave virtually unnoticed. • Others cause disease and destroy the host.

  5. Tiniest of Microbes • They are the tiniest and simplest of microbes. • They can be 10,000 times smaller than bacteria. • Viruses consist of a small collection of genetic material (DNA or RNA) covered in a protective protein coat called a capsid.

  6. Take Over • Once inside a cell the virus takes over. • The virus gives the host cell instructions. • In other words the host cell does all the work and the virus gets all the rewards. • They persuade the host cell to make new viral particles.

  7. Infection • The same virus can cause different reactions in different hosts. • For example, flu viruses infect birds, pigs and humans. • While some of these flu viruses will not harm the birds they can overwhelm and kill humans.

  8. Structure protein coat nucleic acid

  9. Success Criteria • I can describe can describe the structure of viruses.

  10. Learning Outcome • Give an outline of the stages of viral replication.

  11. Bacteriophage

  12. Genetic material (DNA) Protein coat Hollow tail Fibre

  13. bacterium Virus adheres to host cell

  14. Virus adheres to host cell

  15. Virus adheres to host cell

  16. Virus adheres to host cell

  17. Virus adheres to host cell

  18. Virus thrusts tail through cell wall

  19. Virus thrusts tail through cell wall

  20. Virus thrusts tail through cell wall

  21. Virus thrusts tail through cell wall

  22. Virus thrusts tail through cell wall

  23. Virus thrusts tail through cell wall

  24. Virus thrusts tail through cell wall Viral DNA injected into host cell

  25. Virus thrusts tail through cell wall Viral DNA injected into host cell

  26. Virus thrusts tail through cell wall Viral DNA injected into host cell

  27. Viral DNA replicates using bacterial nucleotides

  28. Viral DNA transcribed into viral mRNA which directs formation of protein coats using bacterial amino acids

  29. Each viral DNA becomes enclosed in a protein coat

  30. Each viral DNA becomes enclosed in a protein coat

  31. Each viral DNA becomes enclosed in a protein coat

  32. Host cell bursts releasing many copies of virus

  33. Host cell bursts releasing many copies of virus

  34. To summarise.... • Attachment • Insertion • Replication • Release Remember AIRR

  35. Success Criteria • I can give an outline of the stages of viral replication.

  36. Learning Outcome • Give examples of viral infections and how they are spread.

  37. Group Activity Complete the viruses group activity to find out about viral diseases and how they are spread. Complete the table in your booklet

  38. Success Criteria • I can give example of viral diseases and how the are spread.

  39. Learning Outcome • Name the different parts of the blood and their function.

  40. The blood • The blood is extremely important for the body. • It carries substances to all parts of the body through the circulatory system. • On average a person has 5 litres of blood.

  41. Blood • Plasma • Red Blood Cells • White Blood Cells • Platelets

  42. Plasma • Blood may look like just a red liquid, however, it is made up of a variety of different types of cells all suspended in a fluid. • The main component of blood is a fluid called plasma which is mainly water.

  43. Components of blood • Suspended in the plasma are: • red blood cells and white blood cells. • dissolved substances such as glucose, urea and amino acids • plasma proteins such as antibodies and hormones

  44. Red blood cells • There are around 5 million red blood cells per mm3 of blood. • Their main function is to carry oxygen.

  45. Red blood cells • Red blood cells have a biconcave shape. • This increases their surface area. • They contain a substance called haemoglobin, a red oxygen carrying pigment which gives red blood cells their colour.

  46. Red blood cells • Red blood cells are very special animal cells because they do notcontain a nucleus. • This means they have a maximum amount of space for haemoglobin.

  47. Transport of respiratory gases • Oxygen is carried in red blood cells. • It is attached to a haemoglobin, the red pigment found in rbc. • The oxygen is carried around the body attached to haemoglobin, it can then leave the rbc and diffuse into the body cells.

More Related