final test prep Flashcards
label the structure of DNA.
phosphate - little circle
pentose sugar - pentogen
base - rectangle
where do antigens attach onto antibodies?
on end of the Y and little circle above it.
how does DNA replicate?
The DNA is unwound from the double helix structure. DNA helicase enzymes break the hydrogen bonds between the bases of the DNA. DNA polymerase enzymes add free nucleotides to the daughter strands using complementary base pairing. leading strands synthesise continuously whereas lagging strands synthesis is fragments. DNA ligase enzymes seal the fragments forming 2 identical daughter strands through semi conservative replication.
what is a monoclonal antibody?
produced by a single clone of a specific white blood cell. Specific to 1 binding site on 1 protein antigen.
what’s the difference between DNA and RNA?
dna - double stranded, longer chained, contains thymine, self replicating
rna - single stranded, shorter chained, contains uracil, cant replicate on its own.
how is ATP made?
produced in cells through respiration, energy released in the form on ATP.
made up of adenine, ribose and 3 phosphate
uses of monoclonal antibodies in medicine?
can attach to the cancer drug, designed to bind to antigens expressed on the surface of cancer cells, this allows the drug to be delivered specifically to cancer cells where it will release cancer drugs. this minimises the toxic effect on non cancerous cells.
how does the Eliza test work to form a positive test?
an enzyme is attached to the anitbodies, when the enzyme reacts with certain substrate a coloured product is formed causing the solution in the reaction vessel to change colour. if it changes colour then it shows the antigen or antibody is present.
give 5 properties of water that are good for organisms
high heat capacity, strong cohesion, good solvent, high specific latent heat, metabolic
2 enzymes involved in DNA replication
helicase, ligase, polymerase
how does gas exchange reduce water loss in insects?
close their spiracles to prevent water loss
exoskeleton is covered in waxy cuticle to help prevent water loss
how does gas exchange work in fish?
counter-current system, blood flows through the lamellae in the opposite direction of the flow of water through the gills.
The counter-current system ensures there is always a steep concentration gradient between the water and the blood.
