Exam Questions Flashcards
Role of disulphide bridge in quaternary structure of antibody
Joins 2 different polypeptides
Addition mutation
Frame shift
So affects more than one amino acid
Increase rate of photosynthesis….
Faster/ more growth
Contrast structure of starch and cellulose
Position of hydrogen and hydroxyl groups in carbon atom 1 inverted
Cellulose
Long straight chains
Linked together by many hydrogen bonds
Cross links between chains
Hydrogen bonds strong in large numbers
Resists digestion/ action of microorganisms/ enzymes
Can resist turgor/osmotic pressure
Flipping over of alternate molecules
Exopeptidases
Remove terminal amino acids
Function of chloroplast
Absorb light
For photosynthesis
Produces carbohydrates sugars lipids protein
Cristae in mitochondria
Folding of membrane increases surface area- more proteins for active transport
Starch
Coiled/ helical
Insoluble
Large
Branched
Adaptations of epithelial cells
Microvilli
Many mitochondria
Carrier proteins, co transport proteins, membrane bound enzymes
Antigen
Substance that causes an immune response/ production of antibodies
Molecule on cell surface…
Why antigens can’t get through membrane
Not lipid soluble
Too large to diffuse through membrane
Don’t have complementary shape
Name one organelle expected in large numbers in a mucus secreting cell
Ribosomes- make polypeptide (mucus proteins)
Golgi body- package and process proteins
Mitochondria- release energy
Vesicles- secretion and transport of protein
Stain used for viewing starch grains under microscope
Iodine in potassium iodide
Structures that cannot be viewed under optical microscope
Mitochondrion, ribosomes, lysosomes, cell surface membrane, ER
Explain why potato increased in length
More negative water potential (lower water potential)
Water taken in by osmosis
Causes cells to extend/ become turgid
Why no further decrease in length of potato
Isotonic
Little water remaining
Fully plasmolysed
Cell wall prevents further shrinkage
Functions of phospholipids
Impermeable barrier to water soluble substances
Allows cell to maintain different concentrations either side
Makes membrane fluid, self sealing, able to fuse with other membranes, form vesicles, gives flexibility
Function extrinsic glycoproteins
Cell recognition/identification
Binding to hormones
Advantage of giving results as a ratio
Easy to compare
Shows proportional change
(Eg with osmosis practical, is good method as the discs has different starting masses)
Advantage of taking multiple readings
Mean
Identify anomalies
Plot error bars to show variability about mean
Why babies can test positive for disease like hiv if mother is positive
Antibodies from mother through placenta and breast milk
Always Positive tests before 18 months
Purposes of control well in elisa tests
Shows colour change due to the secondary antibody with the enzyme binding to the hiv antibodies
Washing is effective/ all unbound antibodies washed away
Factors to consider when selecting antibiotics
Side effects, allergic reactions
How much resistance the bacteria have built up
Interactions/ effects on other medications
Narrow spectrum (only act on problem bacteria)
