Back to AI Flashcard MakerBiology /Biology IB HL - 6.3 Disease Defences Part 3
Where does the antigen bind to? (antibodies)
The ends of the arms are where the antigen binds – these areas are called the variable regions and differ between antibodies
Tap or swipe ↕ to flip
Swipe ←→Navigate
1/25
Key Terms
Term
Definition
Where does the antigen bind to? (antibodies)
The ends of the arms are where the antigen binds – these areas are called the variable regions and differ between antibodies
Apart from the variable region (where antigen binds), is the rest of the antibody structure different?
NO
The rest of the molecule is constant across all antibodies and serves as a recognition site for the immune system (opsonisation)
What can antibody-antigen interaction be compared to?
Each type of antibody recognises a unique antigen, making antigen-antibody interactions specific (like enzymes and substrates)
What are antibiotics?
Antibiotics are compounds that kill or inhibit the growth of microbes (specifically bacteria) by targeting prokaryotic metabolism
What are 3 metabolic features that may be targeted by antibiotics?
Metabolic features that may be targeted by antibiotics include key enzymes, 70S ribosomes and components of the cell wall
Do antibiotics target both eu- and prokaryotic cells? Why?
Because eukaryotic cells do not possess these features, antibiotics will target the pathogenic bacteria and not the infected host
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
Where does the antigen bind to? (antibodies) | The ends of the arms are where the antigen binds – these areas are called the variable regions and differ between antibodies |
Apart from the variable region (where antigen binds), is the rest of the antibody structure different? | NO
The rest of the molecule is constant across all antibodies and serves as a recognition site for the immune system (opsonisation) |
What can antibody-antigen interaction be compared to? | Each type of antibody recognises a unique antigen, making antigen-antibody interactions specific (like enzymes and substrates) |
What are antibiotics? | Antibiotics are compounds that kill or inhibit the growth of microbes (specifically bacteria) by targeting prokaryotic metabolism |
What are 3 metabolic features that may be targeted by antibiotics? | Metabolic features that may be targeted by antibiotics include key enzymes, 70S ribosomes and components of the cell wall |
Do antibiotics target both eu- and prokaryotic cells? Why? | Because eukaryotic cells do not possess these features, antibiotics will target the pathogenic bacteria and not the infected host |
In what two general ways may an antibiotic kill invading bacteria? | Antibiotics may either kill the invading bacteria (bactericidal) or suppress its potential to reproduce (bacteriostatic) |
What is the mode of infection for viruses? | Viruses do not possess a metabolism (they are not alive) and instead take over the cellular machinery of infected host cells |
Therefore, are antibiotics effective for viruses? | NO!!!
As such, they cannot be treated with antibiotics and must instead be treated with specific antiviral agents |
What do antiviral treatments target? | Antiviral treatments target features specific to viruses (e.g. viral enzymes like reverse transcriptase or components of the capsid) |
What two types of antibiotics may there be? | Antibiotics can be narrow spectrum (effective against specific bacteria) or broad spectrum (effective against many bacteria) |
When was the first antibiotic discovered? | Since the discovery of the first antibiotic in 1928, antibiotic compounds have been used to treat a variety of bacterial infections |
What have some strains of bacteria developed? | Some strains of bacteria have evolved with genes that confer resistance to antibiotics and some strains have multiple resistance |
How may genes in bacteria confer resistance? | Genes may confer resistance by encoding traits that degrade the antibiotic, block its entry, increase its removal or alter the target |
Why is antibiotic resistance possible in bacteria? | Because bacteria reproduce at a rapid rate, resistant strains of bacteria can proliferate very quickly following the initial mutation |
How can the resistant strain be passed on? | Additionally, resistant strains can pass resistance genes to susceptible strains via bacterial conjugation (horizontal gene transfer)
binary fission |
What are three factors that are causing an increase in the prevalence of resistant bacterial strains? | Antibiotics are often over-prescribed (particularly broad-spectrum drugs) or misused (e.g. given to treat a viral infection)
Many antibiotics are freely available without a prescription and certain antibiotics are commonly included in livestock feed
Multi-drug resistant bacteria are especially common in hospitals (i.e. nosocomial infections) where antibiotic use is high |
What is an example of an antibiotic-resistant strain? | An example of an antibiotic-resistant strain of bacteria is Golden Staph (MRSA – Methicillin Resistant Staphylococcus aureus) |
Who found the first chemical compound? | The first chemical compound found to have antibiotic properties was penicillin, which was identified by Alexander Fleming in 1928 |
How was penicillin found? | The discovery of penicillin was a fortuitous accident, resulting from the unintended contamination of a dish containing S. aureus
A Penicillium mould began to grow on the plate and a halo of inhibited bacterial growth was observed around the mould |
What did Fleming conclude? | Fleming concluded that the mould was releasing a substance (penicillin) that was killing the nearby bacteria |
Who demonstrated the medical application of penicillin? | The medical applications of penicillin as an antibiotic were demonstrated by an Australian scientist, Sir Howard Florey, in 1940 |
What did Florey and Chain test penicillin on? | Working with another scientist (Ernst Chain) and a team of researchers, Florey tested penicillin on infected mice |
What were the mouse infected with? Florey and Chain | Eight mice were injected with hemolytic streptococci and four of these mice were subsequently injected with doses of penicillin |
What were the results of Florey and Chain? | The untreated mice died of bacterial infection while those treated with penicillin all survived – demonstrating its antibiotic potential |