Learning Outcome Describe the structure of viruses Three

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. Some viruses enter a host and leave virtually unnoticed. Others cause disease and destroy the host.

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.

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.

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.

Structure protein coat nucleic acid

Success Criteria I can describe the structure of viruses.

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

Genetic material (DNA) Protein coat Hollow tail Fibre

Host Cell Virus attaches to host cell

Virus attaches to host cell

Virus puts tail through cell wall

Virus pierces through cell wall

Virus pierces through cell wall Viral DNA injected into host cell

Viral DNA replicates

Protein coats are synthesised

Each viral DNA becomes enclosed in a protein coat

Host cell bursts releasing many copies of virus

To summarise. . Attachment Insertion Replication Release Remember AIRR

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

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

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

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

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

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.

Blood Plasma Red Blood Cells White Blood Cells Platelets

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.

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

Red blood cells There around 5 million red blood cells per mm 3 of blood. Their main function is to carry oxygen.

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

Red blood cells are very special animal cells because they do not contain a nucleus. This means they have a maximum amount of space for haemoglobin.

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.

haemoglobin + oxygen —> oxy-haemoglobin

White blood cells There are many different types of white blood cell. They are larger than red blood cells and do contain a nucleus but no haemoglobin. White blood cells are involved in the immune system.

Platelets are tiny cells found in the blood They have no nucleus and their job is to make the blood clot. If a blood vessel is damages platelets rush to the area and form a clump to help stop blood loss.

Success Criteria I can name the different parts of the blood and their function.

Learning Outcome Name and recognise the two main types of white blood cell involved in defence. Describe the process of phagocytosis, as used by white blood cells, stating the importance of lysosomes in this process.

First-line defences Before disease causing organisms can get into the body and cause harm, they must pass several barriers. First-line defences are features of the body that help to prevent the entry of harmful organisms.

First Line of Defence SKIN TEARS HAIR & MUCUS

Second-line defences White blood cells are the second-line defence.

Macrophage A macrophage is a special type of white blood cell which can engulf and digest bacteria. It has a nucleus and special structures called lysosomes which contain digestive enzymes.

Phagocytosis Finding Destroy Engulf Digest

Phagocytosis lysosome Bacterium being engulfed The enzymes digest the bacterium so it is now harmless Bacterium trapped inside vacuole Lysosome release digestive enzymes into vacuole

Success Criteria I can name and recognise the two main types of white blood cell involved in defence. I can describe the process of phagocytosis, as used by white blood cells, stating the importance of lysosomes in this process.

Learning Outcome Explain the role of antibody production in immunity.

Macrophages are a type of non-specific immunity. This is because they work against lots of different pathogens. Specific immunity involves acting against one particular pathogen.

Specific Immune Response A specific immune response is against one particular type of virus. The white blood cells involved are called LYMPHOCYTES. These produce special protein molecules called ANTIBODIES

Lymphocyte If a child catches the chicken pox virus, a specific lymphocyte is stimulated. This lymphocyte then multiplies. All these lymphocytes produce antibodies specifically against the virus. The virus is then destroyed eventually.

Antigens antigen cell Antigens are your body’s way of telling which cells are your own, and which cells are unwanted invaders. Pathogens e. g. bacteria or viruses, have different shaped antigens from your body cells, and your body can tell that they don’t belong.

Antigens are a bit like an identity card. Pathogens don’t carry the right identity card, so your body attacks them. red blood cell Salmonella I cause food poisoning

Lymphocyte produces antibodies specific to the antigen Lymphocyte recognises antigen as non-self Antibodies specifically attack the antigen The bacteria or virus is rendered harmless

Antibodies attach to the viral antigens at receptor sites. This causes the virus to become harmless.

Specific immunity Antibody production is a type of specific immunity. This is because the antibodies being produced only work against one type of antigen.

Defence by antibodies

1. Viral particles become attached to ______ by their antigens. 1. _______enters body cell. 2. Lymphocytes multiply and produce large numbers of ______. 2. Virus ______. 3. ______ and antibodies meet and combine. This makes the antigen ______. Antigens antibodies multiplies Virus lymphocyte harmless

New pathogens you have never been exposed to before attack the body and multiply. This makes you feel ill Lymphocytes detect the foreign antigens on the pathogens Lymphocytes make specific antibodies for the antigen The antibodies attach themselves to the antigens on the pathogens and make them harmless

Lymphocyte remembers the shape of the Pathogen you have previously come into antigen contact with enters your body again Lymphocytes instantly recognise the pathogens and make antibodies immediately The antibodies attach themselves to the pathogens and kill them before the pathogens have a chance to make you ill. You now have immunity!!!

Make a model - The Immune Response v Collect: ü 10 cocktail sticks ü 3 pipe cleaners ü 2 colours of playdoh v You have 10 minutes to design and make a model showing the immune response after exposure to a pathogen v Remember to include: ü pathogen ü antibody ü phagocyte

Key part Part of structure Explanation of what it is/ does? Pathogen A disease causing microbe Antigen Found on the outside of the pathogen Antibody Is made by the white blood cells to kill the pathogen Phagocyte A type of white blood which engulfs and ingests the pathogens Phagocyte Pathogen Antibody q. What was good about your model? q. How do you think it could have been improved?

Success Criteria I can explain the role of antibody production in immunity.

Learning Outcome Explain the importance of knowing blood groups in organ donation.

Blood Grouping A B AB O It is the type of antigens on the surface of your red blood cells which decide your blood group. You will have the opposite antibodies in your plasma

Blood Group A If you belong to the blood group A, you have A antigens on the surface of your red blood cells. You have B antibodies in your blood plasma.

Blood Group B If you belong to the blood group B, you have B antigens on the surface of your red blood cells. You have A antibodies in your blood plasma.

Blood Group AB You have both A and B antigens on the surface of your red blood cells. No A or B antibodies at all in your blood plasma.

Blood Group O You have neither A or B antigens on the surface of your red blood cells. You have both A and B antibodies in your blood plasma.

Who can donate to who? RECIPIENT’S BLOOD GROUP O O DONOR’S BLOOD GROUP A B AB

RECIPIENT’S BLOOD GROUP O No antigens A DONOR BLOOD GROUP Antigen A B Antigen B AB Antigens A& B O A B AB Anti-A & Anti-B Anti-A No antibodies √ √ √ √ √

Questions 1. Who is the ‘universal donor’? 2. Who is the ‘universal recipient’?

Success Criteria I can explain the importance of knowing blood groups in organ donation.

Earl’s Exit A small pool of blood and a knife were found near the bins. After examining the area, the police discovered a body and identified him as Earnest “One Eyed” Earl. The police have collected blood samples from the pool of blood and the weapon. The police need to know their blood types to see if it matches one of the 3 suspects they have identified or if it belongs to the victim.

Suspects 1. Bobby “Baby” Brooks 2. “Slim” Jim Snoot 3. Barbie “Doll” Jones Carry out the blood typing experiment to see if you can identify who the blood on the weapon and at the crime scene belong to: Can you find Earl’s murderer?

Agglutination + X X + + X

Who Did It? ! Blood Samples Blood group Suspect 1 A Suspect 2 B Suspect 3 AB Victim O Crime Scene A Weapon O The blood on the weapon must have belonged to the victim. But the blood left at the crime scene belongs to suspect 1 so he must have killed Earl!